This document discusses fetal pain and the development of the human brain prior to birth. It summarizes that the human brain is more developed than once thought by around 2 months before birth, comparable to a newborn macaque. Neurons in the subplate zone of the fetal brain form functional networks and influence cortical development. While cortical neurons were once thought necessary for conscious pain perception, immaturity alone does not preclude fetal pain, as subcortical structures are also involved in consciousness.
The document discusses whether there is sufficient evidence to support the concept that a fetus can experience pain. It outlines key developments in fetal neurobiology and the anatomical pathways involved in pain processing. While certain pathways are intact by 7 weeks gestation, the brain is not fully developed and lacks key features, such as cortical lamination, until later in gestation. The document concludes that the neurological systems necessary for pain experience are not fully intact and functional until around 26 weeks gestation.
1) A study of fetal anatomy shows that by 20 weeks gestation, the brain structures necessary for consciousness (thalamus and related areas) are developed and accompanied by coordinated EEG rhythms, suggesting consciousness is possible by this point.
2) If a more stringent threshold of continuous EEG is required, consciousness would be possible by 30 weeks gestation.
3) If consciousness is possible beginning at 20-30 weeks gestation, it is also possible that fetuses could experience something like "pain" beginning at this point. The possibility of consciousness and pain would require appropriate anesthesia and analgesia for fetal surgery.
Dermatoglyphic anomalies and neurocognitive deficits in siblingCA. Sanjay Ruia
1) Sibling pairs discordant for schizophrenia spectrum disorders were assessed for neurocognitive performance and dermatoglyphic anomalies.
2) Affected siblings performed significantly worse on tests of executive function, set shifting, and attention compared to their unaffected siblings.
3) Affected siblings also had a greater number of dermatoglyphic anomalies including abnormal palmar flexion creases and ridge dissociations.
4) However, no significant association was found between dermatoglyphic anomalies and neurocognitive deficits in the affected siblings, suggesting a role for genetic or late environmental factors in the origin of their cognitive impairments.
1. The article discusses the development of pain responses from preterm infants through childhood.
2. It notes that while pain pathways are immature early in development, nociceptors and basic pain responses exist even in the youngest preterm infants.
3. The article reviews the maturation of peripheral and central pain pathways from fetal stages through early postnatal life, finding that pathways are functional but immature neonatally and continue developing into childhood.
This article discusses the presence of consciousness in children born with hydranencephaly, a rare condition where the cerebral hemispheres are absent or severely compromised. While it is widely believed that these children lack consciousness, the article reviews evidence that some hydranencephalic children exhibit behaviors indicating basic levels of consciousness, such as recognizing faces, responding preferentially to familiar people/stimuli, and learning associations. However, whether they experience reflective consciousness remains controversial. The article concludes the evidence for some level of consciousness in these children is more convincing than arguments against it.
This document summarizes recent research on the development of nociceptive (pain-sensing) circuits in infants. It discusses how:
1) Nociceptive neurons are specified early in development through molecular pathways involving tyrosine kinase receptors and neurotrophic factors.
2) Functional synapses and neural circuits in the dorsal horn develop over the first postnatal weeks through changes in excitatory and inhibitory synaptic transmission.
3) Sensory activity, both non-nociceptive and excessive nociceptive inputs, can influence the development of pain processing circuits in early life.
The document discusses whether there is sufficient evidence to support the concept that a fetus can experience pain. It outlines key developments in fetal neurobiology and the anatomical pathways involved in pain processing. While certain pathways are intact by 7 weeks gestation, the brain is not fully developed and lacks key features, such as cortical lamination, until later in gestation. The document concludes that the neurological systems necessary for pain experience are not fully intact and functional until around 26 weeks gestation.
1) A study of fetal anatomy shows that by 20 weeks gestation, the brain structures necessary for consciousness (thalamus and related areas) are developed and accompanied by coordinated EEG rhythms, suggesting consciousness is possible by this point.
2) If a more stringent threshold of continuous EEG is required, consciousness would be possible by 30 weeks gestation.
3) If consciousness is possible beginning at 20-30 weeks gestation, it is also possible that fetuses could experience something like "pain" beginning at this point. The possibility of consciousness and pain would require appropriate anesthesia and analgesia for fetal surgery.
Dermatoglyphic anomalies and neurocognitive deficits in siblingCA. Sanjay Ruia
1) Sibling pairs discordant for schizophrenia spectrum disorders were assessed for neurocognitive performance and dermatoglyphic anomalies.
2) Affected siblings performed significantly worse on tests of executive function, set shifting, and attention compared to their unaffected siblings.
3) Affected siblings also had a greater number of dermatoglyphic anomalies including abnormal palmar flexion creases and ridge dissociations.
4) However, no significant association was found between dermatoglyphic anomalies and neurocognitive deficits in the affected siblings, suggesting a role for genetic or late environmental factors in the origin of their cognitive impairments.
1. The article discusses the development of pain responses from preterm infants through childhood.
2. It notes that while pain pathways are immature early in development, nociceptors and basic pain responses exist even in the youngest preterm infants.
3. The article reviews the maturation of peripheral and central pain pathways from fetal stages through early postnatal life, finding that pathways are functional but immature neonatally and continue developing into childhood.
This article discusses the presence of consciousness in children born with hydranencephaly, a rare condition where the cerebral hemispheres are absent or severely compromised. While it is widely believed that these children lack consciousness, the article reviews evidence that some hydranencephalic children exhibit behaviors indicating basic levels of consciousness, such as recognizing faces, responding preferentially to familiar people/stimuli, and learning associations. However, whether they experience reflective consciousness remains controversial. The article concludes the evidence for some level of consciousness in these children is more convincing than arguments against it.
This document summarizes recent research on the development of nociceptive (pain-sensing) circuits in infants. It discusses how:
1) Nociceptive neurons are specified early in development through molecular pathways involving tyrosine kinase receptors and neurotrophic factors.
2) Functional synapses and neural circuits in the dorsal horn develop over the first postnatal weeks through changes in excitatory and inhibitory synaptic transmission.
3) Sensory activity, both non-nociceptive and excessive nociceptive inputs, can influence the development of pain processing circuits in early life.
Sleep And Sudden Infant Death Syndrome Research Infant Arousals During Mother...Biblioteca Virtual
This study examined how bed sharing impacts infant arousal and sleep stages using polysomnography on 35 breastfeeding mother-infant pairs. The study found that bed sharing promoted more frequent infant arousals, especially during quiet/deep sleep stages. Bed sharing also reduced infants' time spent in quiet/deep sleep stages. By facilitating arousals and reducing deep sleep, bed sharing may enhance infants' ability to arouse in response to dangerous situations, potentially protecting against SIDS. The temporal overlap of infant and mother arousals doubled with bed sharing, suggesting mothers may also be more responsive to infants' needs during co-sleeping.
The document discusses evidence related to whether a fetus can experience pain. It summarizes the development of anatomical structures and pathways involved in pain perception in a fetus from 8 weeks gestation onwards. It also discusses physiological evidence from preterm infants that suggests nociceptive pathways are functional from 24-26 weeks gestation. The document considers arguments that a fetus may experience pain in a primitive way without requiring consciousness, self-consciousness, or previous experience. It notes evidence that early painful experiences can have long-term effects on stress responses and sensitivity to pain.
This review discusses the development of fetal pain pathways and consciousness. It summarizes that:
1) The anatomical pathways necessary for nociception are in place by 24 weeks gestation, including connections from peripheral receptors to the spinal cord and thalamus.
2) The subplate zone, which is involved in pain processing, is well-developed between 22-26 weeks and can be influenced by external stimuli via thalamic pathways.
3) Physiological evidence shows somatosensory potentials can be elicited in the fetus from 24 weeks gestation, suggesting nociceptive pathways are functionally developed.
1. Using clonal lineage tracing in the adult mouse dentate gyrus, the study found that neuronal precursors of glutamatergic granule neurons exhibit significant tangential migration along blood vessels, followed by limited radial migration.
2. Genetic birthdating and morphological/molecular analyses identified the neuroblast stage as the main developmental window when tangential migration occurs.
3. Observations of a dense plexus of capillaries associated specifically with neuroblasts provided insight into the role of blood vessels as a substrate for neuronal migration in the adult mammalian brain.
This document discusses whether fetal "awareness" and the ability to experience pain exist, and what precautions should be taken to safeguard fetal welfare during experiments. It summarizes recent reviews on the potential for prenatal consciousness. While fetuses show reflexive responses to stimuli, extensive animal studies show the fetal brain is in a continuous state of unconsciousness maintained by neuroinhibitory mechanisms. Fetuses may not be consciously aware or able to experience pain. Caution is needed in giving analgesics since they can have unique adverse effects on fetuses.
Asking The Right Questions - they key to preventing persistent pain?BodyIn Mind
The document discusses how the brain produces pain and protective responses through nociception and various neural pathways and networks in the brain. It explains that nociception occurs automatically through basic motor responses and sympathetic nervous system responses without conscious awareness. However, the brain can modulate pain through factors like beliefs, knowledge, context and memory. Central sensitization can also cause normally non-painful stimuli to produce pain responses through sensitization of nociceptors and neural pathways in the spinal cord and brain.
Menkes Disease A Differential Diagnosis To Child Abusealisonegypt
1) A 9-month-old male infant presented with repetitive seizures, poor muscle tone, and an enlarged head circumference. Imaging showed a subdural hematoma, initially leading to a diagnosis of shaken baby syndrome.
2) Further examination found pale skin, sparse hair with a pili torti pattern, low copper and ceruloplasmin levels, confirming a diagnosis of Menkes disease.
3) Menkes disease can mimic signs of abuse like subdural hematomas due to brain atrophy and fragile blood vessels. This case highlights the importance of considering alternative diagnoses to avoid misdiagnosing child abuse.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study describes the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders: Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from 9 couples, identifying 2 embryos with mutations and deriving stem cell lines from them. The technique was highly accurate, avoiding transmission of diseases while establishing mutant stem cell lines for research.
Tryptophan metabolism and the kynurenine pathway play an important role in neuropsychiatric disorders and immune regulation. Tryptophan is converted to kynurenine via the enzymes IDO and TDO, with kynurenine then processed differently by astrocytes and microglia in the brain. Pro-inflammatory cytokines increase IDO/TDO activity, depleting tryptophan and producing neurotoxic metabolites, while anti-inflammatory cytokines decrease their activity. Abnormalities in this pathway have been linked to depression, psychosis, Alzheimer's, and autoimmune diseases. IDO also plays a key role in immune tolerance by inhibiting T-cell responses and preventing rejection of the fetus during
This study examines synaptic changes in a mouse model of infantile Batten disease. Researchers isolated synapses from mouse brain regions and identified protein differences between healthy and diseased synapses. They found that synaptic breakdown begins earlier in certain brain regions, suggesting some synapses are more vulnerable than others. The team then used a fruit fly model of Batten disease to test whether modifying levels of candidate proteins identified in mouse synapses could slow disease progression, identifying potential therapeutic targets.
This case report describes an infant who presented with an acute life-threatening event after choking while being bottle fed. The infant became apneic and pulseless, and later developed disseminated intravascular coagulopathy and died. Imaging showed subdural hemorrhages, subarachnoid hemorrhage, and retinal hemorrhages, consistent with nonaccidental injury. However, the autopsy findings provided evidence that the infant's injuries could have resulted from a dysphagic choking event as described by the caretaker, rather than nonaccidental trauma.
This document summarizes a study investigating how the gene encoding the nogo-66 receptor 1 (ngr1) regulates plasticity in the visual cortex during the critical period of development. The study found that mice lacking ngr1 retained characteristics of critical period plasticity into adulthood, including shifts in ocular dominance following brief monocular deprivation. In both juvenile wild-type mice and adult ngr1-deficient mice, monocular deprivation led to a loss of excitatory synaptic input onto inhibitory interneurons that express parvalbumin, indicating increased disinhibition. The study proposes that ngr1 acts to close the critical period by preventing this disinhibitory effect of monocular deprivation in adulthood.
Prevention of lysosomal storage diseases and derivation of1Palaelo
This study used preimplantation genetic diagnosis (PGD) to derive stem cell lines from embryos carrying mutations for four lysosomal storage disorders (LSDs): Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from affected families, resulting in two human embryonic stem cell lines - one from a female Hunter syndrome embryo and one from a compound heterozygote embryo for Gaucher disease. The stem cell lines showed typical embryonic stem cell characteristics and normal karyotypes. This demonstrates the potential of PGD and stem cell derivation to establish disease models and prevent transmission of LSDs.
The document discusses evidence for fetal pain from an evolutionary perspective. It argues that since fish feel pain, and early fetal development resembles the fish stage, fetuses may experience pain from an early stage. Studies showing that fish exhibit wariness after painful stimuli and can remember pain provide support. Further evidence discussed includes fetal learning abilities before birth, functional brain and sensory development by 20 weeks, and lack of self-harm suggesting sensation and memory. While some research has questioned fetal pain capabilities, the overall document makes a case that fetuses may experience some levels of consciousness, sensation and pain beginning fairly early in development.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study evaluated the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders (TSD, GD, FD, HS) in couples at risk. PGD was performed on 28 embryos from 8 couples, identifying 2 embryos with mutations for Hunter syndrome and GD. These embryos were used to derive 2 human embryonic stem cell lines expressing markers of an undifferentiated state. PGD accurately diagnosed mutations in embryos and allowed derivation of disease-specific stem cell lines, demonstrating the potential of PGD to avoid inherited diseases while generating disease models.
This document discusses plasticity in the brain and its implications. It outlines three neurotransmitters involved in learning - glutamate, dopamine, and acetylcholine. It describes developmental plasticity as changes in the brain's structure in response to experience during growth and development. A case study demonstrates adaptive plasticity through a woman who regained functions after a stroke through rehabilitation. The document also discusses sensitive periods in development that are optimal times for learning certain skills like language. Neuroimaging technologies allow researchers to study brain changes associated with learning.
An update of wallace´s zoogeographic regions of the worldCarlos Sáenz
This document reports on a study that mapped global zoogeographic regions by integrating data on the distributions and phylogenetic relationships of over 21,000 amphibian, bird, and mammal species. The study identified 20 distinct zoogeographic regions grouped into 11 larger realms. Key findings include:
1) Support was lacking for several regions previously defined based solely on distributional data.
2) Spatial turnover in phylogenetic composition was higher in the Southern Hemisphere than the Northern Hemisphere.
3) Incorporating phylogenetic information provided insight on historical relationships among regions and identified evolutionarily unique regions.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study describes the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders: Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from 9 couples, identifying 2 embryos with mutations and deriving stem cell lines from them. The technique was highly accurate, avoiding transmission of diseases while establishing mutant stem cell lines for research.
This document appears to be a collection of 11 unfiled note pages with no other context or information provided. The pages are unlabeled and contain no discernible main topics, key details, or overall narrative to summarize.
1) The article proposes that the primary function of consciousness is to integrate competing demands from specialized systems in the nervous system that influence skeletal muscle plans.
2) These "supramodular systems" operate in parallel to control actions like breathing, pain response, elimination, but can only collectively influence action through consciousness.
3) During a "supramodular conflict", when different systems demand opposing skeletal muscle actions, consciousness is necessary to integrate the systems and determine the appropriate response.
The document summarizes developmental reorganization of the human cerebral cortex based on three criteria: 1) presence of transient cellular zones, 2) intensity of specific neurodevelopmental events, and 3) patterns of functional organization. During the first half of gestation, proliferation and migration are dominant, while the second half sees growth of major axonal pathways through transient zones. Initial synaptogenesis begins in the third month and relates to endogenous circuitry. In early preterm infants, thalamic fibers relocate from transient zones and evoked potentials can be recorded, showing coexistence of endogenous and sensory-driven circuitry. In neonates, synaptogenesis is dominant and transient zones disappear gradually.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against developing mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
Sleep And Sudden Infant Death Syndrome Research Infant Arousals During Mother...Biblioteca Virtual
This study examined how bed sharing impacts infant arousal and sleep stages using polysomnography on 35 breastfeeding mother-infant pairs. The study found that bed sharing promoted more frequent infant arousals, especially during quiet/deep sleep stages. Bed sharing also reduced infants' time spent in quiet/deep sleep stages. By facilitating arousals and reducing deep sleep, bed sharing may enhance infants' ability to arouse in response to dangerous situations, potentially protecting against SIDS. The temporal overlap of infant and mother arousals doubled with bed sharing, suggesting mothers may also be more responsive to infants' needs during co-sleeping.
The document discusses evidence related to whether a fetus can experience pain. It summarizes the development of anatomical structures and pathways involved in pain perception in a fetus from 8 weeks gestation onwards. It also discusses physiological evidence from preterm infants that suggests nociceptive pathways are functional from 24-26 weeks gestation. The document considers arguments that a fetus may experience pain in a primitive way without requiring consciousness, self-consciousness, or previous experience. It notes evidence that early painful experiences can have long-term effects on stress responses and sensitivity to pain.
This review discusses the development of fetal pain pathways and consciousness. It summarizes that:
1) The anatomical pathways necessary for nociception are in place by 24 weeks gestation, including connections from peripheral receptors to the spinal cord and thalamus.
2) The subplate zone, which is involved in pain processing, is well-developed between 22-26 weeks and can be influenced by external stimuli via thalamic pathways.
3) Physiological evidence shows somatosensory potentials can be elicited in the fetus from 24 weeks gestation, suggesting nociceptive pathways are functionally developed.
1. Using clonal lineage tracing in the adult mouse dentate gyrus, the study found that neuronal precursors of glutamatergic granule neurons exhibit significant tangential migration along blood vessels, followed by limited radial migration.
2. Genetic birthdating and morphological/molecular analyses identified the neuroblast stage as the main developmental window when tangential migration occurs.
3. Observations of a dense plexus of capillaries associated specifically with neuroblasts provided insight into the role of blood vessels as a substrate for neuronal migration in the adult mammalian brain.
This document discusses whether fetal "awareness" and the ability to experience pain exist, and what precautions should be taken to safeguard fetal welfare during experiments. It summarizes recent reviews on the potential for prenatal consciousness. While fetuses show reflexive responses to stimuli, extensive animal studies show the fetal brain is in a continuous state of unconsciousness maintained by neuroinhibitory mechanisms. Fetuses may not be consciously aware or able to experience pain. Caution is needed in giving analgesics since they can have unique adverse effects on fetuses.
Asking The Right Questions - they key to preventing persistent pain?BodyIn Mind
The document discusses how the brain produces pain and protective responses through nociception and various neural pathways and networks in the brain. It explains that nociception occurs automatically through basic motor responses and sympathetic nervous system responses without conscious awareness. However, the brain can modulate pain through factors like beliefs, knowledge, context and memory. Central sensitization can also cause normally non-painful stimuli to produce pain responses through sensitization of nociceptors and neural pathways in the spinal cord and brain.
Menkes Disease A Differential Diagnosis To Child Abusealisonegypt
1) A 9-month-old male infant presented with repetitive seizures, poor muscle tone, and an enlarged head circumference. Imaging showed a subdural hematoma, initially leading to a diagnosis of shaken baby syndrome.
2) Further examination found pale skin, sparse hair with a pili torti pattern, low copper and ceruloplasmin levels, confirming a diagnosis of Menkes disease.
3) Menkes disease can mimic signs of abuse like subdural hematomas due to brain atrophy and fragile blood vessels. This case highlights the importance of considering alternative diagnoses to avoid misdiagnosing child abuse.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study describes the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders: Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from 9 couples, identifying 2 embryos with mutations and deriving stem cell lines from them. The technique was highly accurate, avoiding transmission of diseases while establishing mutant stem cell lines for research.
Tryptophan metabolism and the kynurenine pathway play an important role in neuropsychiatric disorders and immune regulation. Tryptophan is converted to kynurenine via the enzymes IDO and TDO, with kynurenine then processed differently by astrocytes and microglia in the brain. Pro-inflammatory cytokines increase IDO/TDO activity, depleting tryptophan and producing neurotoxic metabolites, while anti-inflammatory cytokines decrease their activity. Abnormalities in this pathway have been linked to depression, psychosis, Alzheimer's, and autoimmune diseases. IDO also plays a key role in immune tolerance by inhibiting T-cell responses and preventing rejection of the fetus during
This study examines synaptic changes in a mouse model of infantile Batten disease. Researchers isolated synapses from mouse brain regions and identified protein differences between healthy and diseased synapses. They found that synaptic breakdown begins earlier in certain brain regions, suggesting some synapses are more vulnerable than others. The team then used a fruit fly model of Batten disease to test whether modifying levels of candidate proteins identified in mouse synapses could slow disease progression, identifying potential therapeutic targets.
This case report describes an infant who presented with an acute life-threatening event after choking while being bottle fed. The infant became apneic and pulseless, and later developed disseminated intravascular coagulopathy and died. Imaging showed subdural hemorrhages, subarachnoid hemorrhage, and retinal hemorrhages, consistent with nonaccidental injury. However, the autopsy findings provided evidence that the infant's injuries could have resulted from a dysphagic choking event as described by the caretaker, rather than nonaccidental trauma.
This document summarizes a study investigating how the gene encoding the nogo-66 receptor 1 (ngr1) regulates plasticity in the visual cortex during the critical period of development. The study found that mice lacking ngr1 retained characteristics of critical period plasticity into adulthood, including shifts in ocular dominance following brief monocular deprivation. In both juvenile wild-type mice and adult ngr1-deficient mice, monocular deprivation led to a loss of excitatory synaptic input onto inhibitory interneurons that express parvalbumin, indicating increased disinhibition. The study proposes that ngr1 acts to close the critical period by preventing this disinhibitory effect of monocular deprivation in adulthood.
Prevention of lysosomal storage diseases and derivation of1Palaelo
This study used preimplantation genetic diagnosis (PGD) to derive stem cell lines from embryos carrying mutations for four lysosomal storage disorders (LSDs): Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from affected families, resulting in two human embryonic stem cell lines - one from a female Hunter syndrome embryo and one from a compound heterozygote embryo for Gaucher disease. The stem cell lines showed typical embryonic stem cell characteristics and normal karyotypes. This demonstrates the potential of PGD and stem cell derivation to establish disease models and prevent transmission of LSDs.
The document discusses evidence for fetal pain from an evolutionary perspective. It argues that since fish feel pain, and early fetal development resembles the fish stage, fetuses may experience pain from an early stage. Studies showing that fish exhibit wariness after painful stimuli and can remember pain provide support. Further evidence discussed includes fetal learning abilities before birth, functional brain and sensory development by 20 weeks, and lack of self-harm suggesting sensation and memory. While some research has questioned fetal pain capabilities, the overall document makes a case that fetuses may experience some levels of consciousness, sensation and pain beginning fairly early in development.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study evaluated the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders (TSD, GD, FD, HS) in couples at risk. PGD was performed on 28 embryos from 8 couples, identifying 2 embryos with mutations for Hunter syndrome and GD. These embryos were used to derive 2 human embryonic stem cell lines expressing markers of an undifferentiated state. PGD accurately diagnosed mutations in embryos and allowed derivation of disease-specific stem cell lines, demonstrating the potential of PGD to avoid inherited diseases while generating disease models.
This document discusses plasticity in the brain and its implications. It outlines three neurotransmitters involved in learning - glutamate, dopamine, and acetylcholine. It describes developmental plasticity as changes in the brain's structure in response to experience during growth and development. A case study demonstrates adaptive plasticity through a woman who regained functions after a stroke through rehabilitation. The document also discusses sensitive periods in development that are optimal times for learning certain skills like language. Neuroimaging technologies allow researchers to study brain changes associated with learning.
An update of wallace´s zoogeographic regions of the worldCarlos Sáenz
This document reports on a study that mapped global zoogeographic regions by integrating data on the distributions and phylogenetic relationships of over 21,000 amphibian, bird, and mammal species. The study identified 20 distinct zoogeographic regions grouped into 11 larger realms. Key findings include:
1) Support was lacking for several regions previously defined based solely on distributional data.
2) Spatial turnover in phylogenetic composition was higher in the Southern Hemisphere than the Northern Hemisphere.
3) Incorporating phylogenetic information provided insight on historical relationships among regions and identified evolutionarily unique regions.
Prevention of lysosomal storage diseases and derivation of2Palaelo
This study describes the use of preimplantation genetic diagnosis (PGD) to prevent the transmission of four lysosomal storage disorders: Tay-Sachs disease, Gaucher disease, Fabry disease, and Hunter syndrome. PGD was performed on 28 embryos from 9 couples, identifying 2 embryos with mutations and deriving stem cell lines from them. The technique was highly accurate, avoiding transmission of diseases while establishing mutant stem cell lines for research.
This document appears to be a collection of 11 unfiled note pages with no other context or information provided. The pages are unlabeled and contain no discernible main topics, key details, or overall narrative to summarize.
1) The article proposes that the primary function of consciousness is to integrate competing demands from specialized systems in the nervous system that influence skeletal muscle plans.
2) These "supramodular systems" operate in parallel to control actions like breathing, pain response, elimination, but can only collectively influence action through consciousness.
3) During a "supramodular conflict", when different systems demand opposing skeletal muscle actions, consciousness is necessary to integrate the systems and determine the appropriate response.
The document summarizes developmental reorganization of the human cerebral cortex based on three criteria: 1) presence of transient cellular zones, 2) intensity of specific neurodevelopmental events, and 3) patterns of functional organization. During the first half of gestation, proliferation and migration are dominant, while the second half sees growth of major axonal pathways through transient zones. Initial synaptogenesis begins in the third month and relates to endogenous circuitry. In early preterm infants, thalamic fibers relocate from transient zones and evoked potentials can be recorded, showing coexistence of endogenous and sensory-driven circuitry. In neonates, synaptogenesis is dominant and transient zones disappear gradually.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against developing mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
This document examines the possibility of fetal pain based on anatomical and psychological evidence. It finds that:
1) The basic anatomy for pain processing, including free nerve endings and connections from the spinal cord to the thalamus, develop by 7 weeks gestation. However, the nervous system is still immature at this stage without laminar brain structures or cortical development.
2) More advanced connections from the thalamus to the cortex begin to form between 12-16 weeks, but these connections initially target the transient subplate zone and not the cortical plate.
3) For pain to be experienced, unique in utero neuroinhibitors that maintain unconsciousness must be overcome, and the psychological elements of experience
This document discusses anesthesia considerations for fetal surgery procedures. It describes how open fetal surgery requires general anesthesia but minimal invasive procedures can be done with local or regional anesthesia. Ex-utero intrapartum treatment procedures are open fetal surgeries but can be done with regional anesthesia if uterine relaxation can be achieved without volatile anesthetics using intravenous nitroglycerin. Both maternal and fetal factors must be considered during fetal anesthesia as the fetus is at risk from hypothermia, hypoperfusion and hypoxia during surgery due to its immature organ systems.
This bill seeks to ensure that women seeking abortions after 20 weeks of fertilization are informed about evidence that unborn children at this stage of development can experience pain during certain abortion procedures. The bill cites several findings regarding the capacity for unborn children to feel pain after 20 weeks of development, as well as existing laws and regulations that aim to protect animals and fetuses from unnecessary pain and discomfort. If passed, it would add a new title to the Public Health Service Act requiring abortion providers to inform women of the pain the unborn child could experience during the procedure.
A feature about latest research to improve premature babies' medical care.
Published in The Lancet Neurology:
http://www.lancet.com/journals/laneur/article/PIIS1474-4422%2813%2970041-3/fulltext
Contributions of Neuroscience toOur Understanding of CognitiAlleneMcclendon878
Contributions of Neuroscience to
Our Understanding of Cognitive
Development
Adele Diamond1 and Dima Amso2
1
Department of Psychiatry, University of British Columbia, and Department of Child and Adolescent Psychiatry,
BC Children’s Hospital, Vancouver, Canada; and
2
Sackler Institute for Developmental Psychobiology,
Weill Medical College of Cornell University
ABSTRACT—One major contribution of neuroscience to
understanding cognitive development has been in demon-
strating that biology is not destiny—that is, demonstrating
the remarkable role of experience in shaping the mind,
brain, and body. Only rarely has neuroscience provided
wholly new insights into cognitive development, but often
it has provided evidence of mechanisms by which obser-
vations of developmental psychologists could be explained.
Behavioral findings have often remained controversial
until an underlying biological mechanism for them was
offered. Neuroscience has demonstrated promise for de-
tecting cognitive problems before they are behaviorally
observable—and, hence, promise for early intervention. In
this article, we discuss examples drawn from imitation and
mirror neurons, phenylketonuria (PKU) and prefrontal
dopamine, maternal touch and stress reactivity, and non-
genetic (behavioral) intergenerational transmission of bi-
ological characteristics.
KEYWORDS—plasticity; epigenesis; mothering; executive
functions; animal models; molecular genetics; memory
Neuroscience research has made its greatest contributions to the
study of cognitive development by illuminating mechanisms
(providing a ‘‘how’’) that underlie behavioral observations made
earlier by psychologists. It has also made important contribu-
tions to our understanding of cognitive development by dem-
onstrating that the brain is far more plastic at all ages than
previously thought—and thus that the speed and extent by which
experience and behavior can shape the brain is greater than al-
most anyone imagined. In other words, rather than showing that
biology is destiny, neuroscience research has been at the fore-
front of demonstrating the powerful role of experience throughout
life. Besides the surprising evidence of the remarkable extent
of experience-induced plasticity, rarely has neuroscience given
us previously unknown insights into cognitive development, but
neuroscience does offer promise of being able to detect some
problems before they are behaviorally observable.
PROVIDING MECHANISMS THAT CAN ACCOUNT FOR
BEHAVIORAL RESULTS REPORTED BY
PSYCHOLOGISTS
Here we describe two examples of behavioral findings by psy-
chologists that were largely ignored or extremely controversial
until underlying biological mechanisms capable of accounting
for them were provided by neuroscience research. One such
example concerns cognitive deficits documented in children
treated early and continuously for phenylketonuria (PKU). The
second example involves neonatal imitation observed b ...
1. The document discusses the importance of skin-to-skin contact between mothers and newborns from a neuroscience perspective. It summarizes evidence that separation from the mother is a form of toxic stress that can disrupt brain development and have lifelong negative impacts on learning, behavior, and health.
2. The author argues that reducing toxic stress for newborns is very easy and involves practices like skin-to-skin contact, attachment, bonding, and breastfeeding that allow the mother's body to regulate the infant's physiology. Public health policies should focus on supporting these early interactions between mothers and babies.
3. Evidence is presented showing that early adversity can get "under the skin" and alter stress response systems
1) The document discusses the development of the fetal pain pathway and whether the fetus can feel pain from invasive procedures.
2) It notes that the necessary neuroanatomical structures for pain perception, like intact thalamocortical connections, do not develop until 26 weeks of gestation.
3) While the fetus reacts to stimuli through stress responses, there is no evidence these reactions involve conscious awareness or feeling of pain. However, providing fetal analgesia can reduce the stress response caused by invasive procedures.
The document discusses the evolution of pain perception and evidence that fetal pain perception may develop earlier than previously thought. It notes that by the third month of development, the fetal nervous system is developed enough to experience pain, as evidenced by studies showing fish and other early evolutionary stages can feel pain. Additional studies on fetal learning and responses to stimuli in the womb provide evidence for a level of consciousness and pain perception before the third trimester. While some research disputes these findings, the document argues that the ability to perceive and avoid harm is necessary for survival and is thus an evolved trait present early in development.
This document proposes a neurobiological model for understanding the effects of early brainstem functioning on the development of behavior and emotion regulation in infants. The model incorporates three integrated levels: (1) brainstem-related physiological regulation, (2) emotion and attention regulation drawing on brainstem-limbic integration, and (3) higher-level outcomes drawing on intact brainstem-limbic networks. Prenatal and perinatal risk factors can disrupt brainstem functioning, which may impact later regulatory capacities. Assessing brainstem dysfunction in high-risk neonates could help identify infants at risk of self-regulatory deficits and inform longitudinal studies of developmental outcomes.
The insular cortex is an area of the brain that is involved in smoking cessation. Scientists recently identified the insular cortex as playing a key role in helping smokers quit. The insular cortex processes internal body sensations and regulates cravings and urges. Damage or abnormalities in this region have been linked to addiction and substance abuse issues.
Scientists are using new technologies like fMRI to study how the brain is affected by experiences like learning a new language or playing video games. Animal models and human studies show that the brain remains plastic throughout life, changing with new experiences. Research on neurogenesis and neural communication has provided insights into development and learning. Studies on animal behavior have also helped explain behaviors and how animals survive.
The document discusses chemical imbalances in the brain and their relationship to mental disorders. It acknowledges that while chemical imbalances have not been pinpointed as the direct causes of specific disorders, they are real factors that can contribute to neural dysfunction. Treatment and prevention of chemical imbalances early on may help avoid full symptoms of mental conditions. The document also examines various brain imaging techniques and neurotransmitters implicated in disorders like depression.
Schizophrenia is a collection of neurodevelopmental disorders involving alterations in brain circuits during early development. While psychosis occurs late, prevention is key. Recent research integrates genetics, neuroimaging, biomarkers and patient-specific cell cultures to map pathophysiology across stages. This enables early detection, personalized treatment selection and outcome monitoring. Going forward, multidimensional classification systems may integrate these data to transform care through prevention, early intervention and integrated treatment approaches.
The document summarizes chronic disorders of consciousness, specifically the vegetative state and minimally conscious state. It discusses:
1) The vegetative state is characterized by wakefulness without awareness due to diffuse brain damage sparing the brainstem. Patients show sleep-wake cycles and reflexes but no signs of consciousness.
2) The minimally conscious state involves minimal but discernible awareness demonstrated through inconsistent responses, in contrast with the vegetative state which shows no awareness.
3) Assessing the level of awareness is difficult but important for correctly diagnosing the disorder of consciousness, as misdiagnoses are common. Sophisticated assessment methods have been developed to carefully evaluate awareness.
The document discusses the evolution of nervous systems in invertebrates and vertebrates. It describes how invertebrates like sponges, cnidarians, flatworms, and mollusks have a ganglionic nervous system with nerve cords and ganglia. Vertebrates evolved a cerebrospinal nervous system with a centralized brain and spinal cord. The cerebrospinal system allows for more complex processing and specialized functions in different brain regions. Comparing nervous system organization across species provides insights into neurodegenerative diseases and potential new treatment strategies.
Adult Neurogenesis and it's Role in Alzheimer'sAbhishek Das
This document summarizes adult neurogenesis and its role in brain disorders such as Alzheimer's disease. It describes how new neurons are generated from neural stem cells in the subventricular zone and hippocampus of the adult brain. Alterations in neurogenesis are linked to neurological conditions like Alzheimer's, where neurofibrillary tangles and amyloid plaques accumulate and neurons die, affecting areas like the hippocampus early on. Efforts are underway to understand how neurogenesis contributes to disease and potentially harness neural stem cells to help repair symptoms.
Abhishek Das_20131056_BIO334_Adult Neurogenesis_RevisedAbhishek Das
This document summarizes adult neurogenesis and its role in brain disorders such as Alzheimer's disease. It describes how new neurons are generated from neural stem cells in the subventricular zone and hippocampus of the adult brain. Alterations in neurogenesis are linked to neurological conditions - decreased neurogenesis is associated with Alzheimer's disease, where neurofibrillary tangles and amyloid plaques accumulate and cause neuronal death. Efforts are being made to understand how neurogenesis contributes to disease and potentially harness neural stem cells to help repair symptoms.
Cortical dysplasia is a malformation of cortical development caused by abnormal neuronal migration or organization during brain development. It can cause intractable epilepsy and neurodevelopmental disorders like autism. The lecture discusses normal brain development and corticogenesis. It then covers specific malformations including focal cortical dysplasia, describing their histopathology and clinical correlates. Recent research suggests focal disruptions of cortical layering found in children with autism may represent early cortical dysplasia, providing insight into a potential cause of autism.
The research showing how exposure to extreme stress affects
brain function is making important contributions to understanding the nature of traumatic stress. This includes the notion that traumatized individuals are vulnerable to react to sensory information with sub-cortically initiated responses that are irrelevant, and often harmful, in the present. Reminders of traumatic experiences activate brain regions that support intense emotions, and decrease activation in the central nervous system (CNS) regions involved in (a) the integration of sensory input with motor output, (b) the modulation of physiological arousal, and (c) the capacity to communicate experience in words. Failures of attention and memory in post-traumatic stress disorder (PTSD) interfere with the capacity to engage in the present: traumatized individuals “lose their way in the world.” This article discusses the implications of this research by suggesting that effective treatment needs to involve (1) learning to tolerate feelings and sensations by increasing the capacity for interoception, (2) learning to modulate arousal, and (3) learning that after confrontation with physical helplessness it is essential to engage in taking effective action.
Neuroplasticity: The Brain That Changes ItselfS'eclairer
The document discusses neuroplasticity and how the brain can change itself through experiences like stress, beliefs, environment, and activities. It provides examples of research that shows how thinking patterns can impact health conditions like heart disease, how environments and experiences can influence gene expression, and how cognitive behavioral therapy and mindfulness can help rewire the brain and reduce symptoms of obsessive compulsive disorder.
This document discusses the rising rates of premature birth worldwide and the associated neurodevelopmental disabilities. While medical advances have improved survival rates for extremely premature infants, rates of long-term disabilities remain high. Brain injuries are the most common neurological consequence and can include cerebral palsy and cognitive impairments. Researchers are working to better understand brain development and identify biomarkers to predict injuries, as well as develop more targeted neuroprotective treatments beyond the only currently effective therapy of therapeutic hypothermia. Precision treatments are needed to protect the developing brain from common stresses in premature infants like hypoxia and infection.
The document discusses evidence that fetuses are capable of feeling pain from as early as 8 weeks gestation. It notes that by 20 weeks gestation, the fetal brain has a full complement of neurons and EEG recordings are possible, indicating the fetus is capable of experiencing pain from 20 weeks onward. The document also discusses the gene c-fos, which is activated in response to painful stimuli and is a marker for pain in the central nervous system. Fos expression has been found in fetal bones as early as 16 weeks gestation, suggesting the fetus is capable of feeling pain from that point.
The document discusses evidence that fetuses are capable of feeling pain from as early as 8 weeks gestation. It notes that by 20 weeks gestation, the fetal brain has a full complement of neurons and EEG recordings are possible, indicating the fetus is capable of experiencing pain from 20 weeks onward. The document also discusses the gene c-fos, which is activated in response to painful stimuli and is a marker for pain in the central nervous system. Fos expression has been found in fetal bones as early as 16 weeks gestation, suggesting the fetus is capable of feeling pain from that point.
Similar to International association for the study of pain (20)
An unborn child has the capacity to feel pain by 20 weeks gestation according to scientific evidence. By this point in development, the neural pathways, nerve tracts, thalamus, and cortex necessary to feel pain are all present. Studies show the unborn child responds to touch as early as 6 weeks and releases stress hormones when injected with a needle at 18 weeks, similar to the stress response in adults feeling pain. While abortion methods do not provide anesthesia to the unborn child, commercial livestock must be rendered insensible to pain before slaughter according to federal law.
This document discusses two approaches to understanding associative learning: the propositional approach and the dual-system approach. The propositional approach argues that associative learning results from controlled reasoning processes, while the dual-system approach argues it results from both controlled reasoning and the automatic formation of links between mental representations. The authors review evidence from past research and conclude that there is little support for the automatic link-formation mechanism proposed by the dual-system approach. Instead, they argue learning is better understood as resulting from propositional reasoning processes.
This document discusses the concept of fetal pain and whether a fetus is capable of perceiving pain. It explores definitions of pain, the anatomical and neurophysiological development of the fetal nervous system, and behavioral responses to stimuli. While connections from the spinal cord to the thalamus develop by 20 weeks, and thalamocortical connections are present from around 26 weeks, the document notes debate around whether these are necessary for pain perception. It concludes that while the very young fetus is likely incapable of feeling pain, the capacity for pain perception likely develops before full term birth.
The document reviews the development of the fetal pain system and debates whether a fetus can feel pain. It finds that:
1) While reflex reactions to noxious stimuli can occur very early in development, cortical processing required for the emotional experience of pain likely only emerges after 26 weeks of gestation with the development of thalamo-cortical connections.
2) Before the cortex is involved, noxious stimuli can still trigger stress responses that affect development.
3) Rather than speculate on fetal pain, the clinically relevant aim is to avoid noxious stimuli to prevent their potential adverse effects on development.
This document summarizes a research article about the mental capacities of newborn infants. It argues that while newborns appear helpless, research shows they have an integrated consciousness and can engage in synchronized interactions with caregivers. This suggests newborns have intersubjective minds, emotions, and motives for social engagement. The study of infant cognition required moving beyond theories of the mind as developing through experience and language alone, to recognize innate capacities for shared intentionality and cultural learning from birth.
This commentary agrees with Shanahan's view that language acquisition has an emotional basis. It provides a supplementary neuroscience perspective, arguing that:
1) Primary-process emotional systems in subcortical brain regions like the central amygdala generate affective intensity, not just secondary cognitive processes.
2) Social-emotional systems like separation distress, nurturance, play, and lust motivated the development of inter-subjective communication between mothers and infants, which may have promoted linguistic prosody.
3) Early affective communication through melodic "motherese" engages infants more than cognitive thought, and music is tightly linked to language in brain and development. Language may have evolved from our emotional nature through
The study recorded EEG signals simultaneously from the scalp and thalamus of 7 patients undergoing deep brain stimulation for essential tremor. The patients performed a go/no-go task where they had to either execute or withhold a cued finger movement based on subsequent go or no-go cues. Event-related potentials differentiated between go and no-go conditions earlier at thalamic recording sites compared to scalp sites, suggesting the thalamus is involved in early classification of go and no-go instructions. Correlations between thalamic and frontal scalp responses were stronger for no-go activities, indicating the thalamus provides information to frontal areas involved in inhibiting prepared actions. The findings support a role for the thalamus
The document discusses whether a fetus can feel pain and at what gestational age. It examines the anatomical, physiological, and behavioral evidence. While the fetus's experience of pain cannot be directly measured, the neural pathways for pain are developed by 20 weeks gestation. The fetus shows stress responses to invasive procedures from 16 weeks onward. Therefore, it is possible the fetus can feel pain from 20 weeks of gestation. More research is needed to fully understand fetal pain and how to provide appropriate analgesia during invasive prenatal procedures.
This randomized, double-blind study compared remifentanil and diazepam for fetal immobilization and maternal sedation during fetoscopic surgery. The study found that remifentanil produced better fetal immobilization with mild maternal respiratory depression, allowing for shorter surgeries, while diazepam resulted in greater maternal sedation but less fetal immobilization and longer surgeries. Remifentanil may thus be superior to diazepam for fetal immobilization during fetoscopic procedures.
The article discusses pain and stress responses in the human fetus. It notes that fetuses likely develop the physiological capacity to feel pain between 20-26 weeks gestation as the connections between the thalamus and cortex develop during this period. The article references evidence that fetuses as young as 18 weeks can experience rises in stress hormones in response to noxious stimuli like invasive medical procedures. While cortical involvement is thought necessary for a conscious pain experience, the fetus may experience pain prior to full cortical development due to subplate zone connections between 20-26 weeks gestation.
This summary provides the key details from the document in 3 sentences:
The document discusses an experimental drug that has shown promise in stopping the hepatitis C virus from replicating and reducing virus levels in test subjects by over 1000 times. It also mentions that surveys found some tanning bed users exhibited behaviors indicating addiction to tanning, and interventions are needed to address addiction and anxiety regarding skin cancer risks. Additionally, it briefly outlines the debate around a new Nebraska law restricting abortion claiming fetuses can feel pain at 20 weeks, which is contradicted by experts saying the structures and ability to feel pain do not exist until later in development.
This document discusses disagreements between Lisa Feldman Barrett's view of emotions and Jaak Panksepp's theory of basic emotions. Panksepp argues that Barrett does not adequately consider evidence from animal studies of how stimulating specific brain regions produces distinct emotional states. He believes multiple basic emotional systems exist in the brain beyond just positive and negative affect. Panksepp claims human brain imaging and physiology are not robust enough on their own to determine basic vs complex emotions. He advocates considering causal evidence from animal models to better understand the neural bases of human emotion.
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...EduSkills OECD
Andreas Schleicher, Director of Education and Skills at the OECD presents at the launch of PISA 2022 Volume III - Creative Minds, Creative Schools on 18 June 2024.
Level 3 NCEA - NZ: A Nation In the Making 1872 - 1900 SML.pptHenry Hollis
The History of NZ 1870-1900.
Making of a Nation.
From the NZ Wars to Liberals,
Richard Seddon, George Grey,
Social Laboratory, New Zealand,
Confiscations, Kotahitanga, Kingitanga, Parliament, Suffrage, Repudiation, Economic Change, Agriculture, Gold Mining, Timber, Flax, Sheep, Dairying,
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Elevate Your Nonprofit's Online Presence_ A Guide to Effective SEO Strategies...TechSoup
Whether you're new to SEO or looking to refine your existing strategies, this webinar will provide you with actionable insights and practical tips to elevate your nonprofit's online presence.
Elevate Your Nonprofit's Online Presence_ A Guide to Effective SEO Strategies...
International association for the study of pain
1. ®
PAIN
INTERNATIONAL ASSOCIATION FOR THE STUDY OF PAIN®
Clinical
Updates
Volume XIV, No. 2 June 2006
EDITORIAL BOARD
Editor-in-Chief
Daniel B. Carr, MD
Internal Medicine, Endocrinology,
Fetal Pain?
Anesthesiology
USA
Advisory Board
Elon Eisenberg, MD
F etal pain has so many implications that it requires a scientific appraisal
independent of the heated controversies regarding abortions, women’s rights,
Neurology
Israel or the beginnings of human life. These implications include pain perception in
James R. Fricton, DDS, MS preterm neonates, anesthesia for fetal surgery or intra-uterine procedures, and
Dentistry, Orofacial Pain the long-term consequences of perinatal anesthesia/analgesia on brain develop-
USA
Maria Adele Giamberardino, MD
ment. Published during the current IASP Global Year Against Pain in Children,
Internal Medicine, Physiology this issue of Pain: Clinical Updates summarizes the evidence concerning fetal
Italy
pain, evaluates recent reviews of this topic, and explores future research in
Cynthia R. Goh, MB BS, FRCP, PhD
Palliative Medicine this field.
Singapore
Alejandro R. Jadad, MD, PhD
Anesthesiology, Evidence-Based Fetal pain requires a scientific appraisal
Medicine and Consumer Issues
Canada independent of the heated controversies regarding
Andrzej W. Lipkowski, PhD, DSc
Neuropharmacology and abortions, women’s rights, or the beginnings
Peptide Chemistry
Poland of human life
Patricia A. McGrath, PhD
Psychology, Pediatric Pain
Canada Human Brains Are Well Developed Prior to Birth
Mohammad Sharify, MD
Family Medicine, Rheumatology By convention, assessments of brain development are mostly based upon
Iran somatomotor development at birth, by which point the human brain has already
Bengt H. Sjolund, MD, PhD
Neurosurgery, Rehabilitation
achieved a relatively advanced stage of development. Comparisons between
Sweden species1 show that more than two months before birth, the human brain is at the
Maree T. Smith, PhD developmental stage of the newborn macaque, a species considered quite preco-
Pharmacology
Australia cious at birth.2 Human newborns are capable of complex processing, including
Harriët M. Wittink, PhD, PT abstract processing of the shapes of objects and the properties of numbers,
Physical Therapy
The Netherlands
implying advanced prenatal development of sensory processing. Earlier argu-
ments against the possibility of fetal pain were based upon the immaturity of,
Production
Elizabeth Endres, Copy Editing
or inhibition of, cortical neurons and thalamocortical inputs in the fetus,3,4 as
Kathleen E. Havers, Executive Assistant these elements are considered essential for conscious pain perception. However,
Juana Braganza Peck, Layout/Graphics
immaturity or hypofunction of cortical neurons are not by themselves sufficient
to preclude the occurrence of fetal pain.
UPCOMING ISSUES Neurons in the Subplate Zone Are Functional
Neurons in the subplate zone of the forebrain, which later separates to in-
Pediatric Pain
clude interstitial neurons in the subjacent white matter and neurons in cortical
Cancer Pain layer I, form an intrinsic synaptic network within which synaptic communication
Placebo relies upon glutamate, gamma-aminobutyric acid, acetylcholine, neuropeptides,
Supported by an educational grant from Endo Pharmaceuticals Inc., USA
2. Comparisons between species show that sies or dream-like experiences, suggesting that the observer
more than two months before birth, function of consciousness is separable from its cortical content.
Lesions in the reticular activating system, but not the cortex,
the human brain is at the developmental lead to loss of consciousness.
stage of the newborn macaque Transient lapses of consciousness also occur in absence
epilepsy, associated with distinctive electroencephalogram
and calcium-binding proteins. The somatosensory subplate zone (EEG) patterns of synchronously evolving bilateral spike and
receives distinct inputs from the thalamus and the neocortex5 wave discharges. These discharges show a symmetrical coinci-
and reaches four times the width of the somatosensory cortex in dence of even the first abnormal EEG spike bilaterally, incon-
the human fetus (and twice the width in the monkey). Neurons sistent with epileptic spread across interhemispheric pathways,
in the subplate zone initiate excitatory amino acid or peptide but instead resulting from paroxysmal discharges in midline
neurotransmission in the cortex, influencing the development of subcortical structures, which are radially and symmetrically
fetal cortical circuits.6,7 Differentiation of subplate neurons at connected with both cerebral hemispheres. This EEG pattern
17–25 weeks’ gestation produces five cellular subtypes whose cannot be produced by experimental stimulation of cortical
distinct dendritic and axonal patterns correspond to different areas, but is evoked by stimulation of the midline thalamus. The
functional roles in development. Changes in the subplate zone Nobel laureate Edelman and colleagues have also reviewed the
are evident in the lamination patterns of the developing human criteria for consciousness in animal species and concluded that
fetal cerebral cortex.8,9 the mechanisms for consciousness are not exclusively cortical.
Subplate neurons remaining in deep cortical layers have Further clinical evidence for conscious perception mediated
been termed “vestigial remnants,” simply because subplate by subcortical centers comes from infants and children with
neurons in other areas undergo programmed cell death during hydranencephaly.12,13 Despite total or near-total absence of the
normal development. Yet a high proportion of spinal cord neu- cortex, these children clearly possess discriminative awareness.
rons also normally die prior to maturity, with no suggestions They distinguish familiar from unfamiliar people and environ-
that remaining neurons are vestigial. Maintaining “vestigial” ments and are capable of social interaction, visual orienting,
neurons would be metabolically expensive and unlikely to musical preferences, appropriate affective responses, and asso-
occur in normal development. Subplate neurons are optimally ciative learning.14
positioned for efficient communication, with sparse connections Thus, a subcortical system comprising the basal ganglia,
across time and space and rich inputs from cortical and thalamic medial and midline thalamic nuclei, substantia nigra, ventral
afferents. These neurons play essential roles in the formation tegmental area, superior colliculi, midbrain, and pontine reticu-
of ocular dominance columns, sensory receptive fields, and lar formation mediates the organization of consciousness.15
cortical gyri. They are particularly vulnerable to preterm In the words of Penfield and Jasper, this system does not func-
injuries that produce cognitive and sensory deficits during later tion “by itself alone, independent of the cortex,” but “by means
childhood. of employment of various cortical areas.” That intact forebrain
Apoptosis of subplate cells in superficial layers leaves commissures are not required for high levels of cognitive func-
behind well-connected subplate cells in deep cortical layers that tion16 provides further evidence for the subcortical integration
form the earliest cortical circuits. Their connectivity strongly of both cerebral hemispheres, symmetrically and radially
correlates with the behaviorally relevant component of evoked connected to this midline system.
responses termed “N1,” which represents sensory perception in Multiple lines of evidence thus corroborate that the key
primates and is initiated in cortical layer I.10 These superficial mechanisms of consciousness or conscious sensory perception
connections, initially formed in the subplate zone, are essential are not dependent on cortical activity. Consistent with this evi-
components of the cognitive processing by which sensory dence, the responses to noxious stimulation of children with
information is primed, guided, and interpreted.10,11 hydranencephaly are purposeful, coordinated, and similar to
those of intact children.14 Further, preterm neonates or adoles-
cents with cortical parenchymal injury mount biobehavioral
Consciousness Occurs below the Cerebral Cortex responses to pain that are indistinguishable from those of nor-
Half a century ago, neurosurgeon Wilder Penfield noted mal controls. Whether consciousness is required for sensory
that large amounts of the cerebral cortex could be excised, even perception has also been questioned by recent studies of adult
as extensive as hemispherectomy, while he continued to con- patients in a persistent vegetative state.17,18
verse with his patients, who suffered no evident impairment of
consciousness. Surgical removal of dysfunctional portions of Attempts to set forth criteria for fetal
the cerebral cortex that contained epileptic foci deprived these consciousness create difficulties of
patients of stored information or discriminative capacities, but measurement and conundrums
not consciousness itself. Based on findings from more than 750
patients, Penfield and Jasper proposed that “the highest integra- of proof and disproof
tive functions of the brain are not completed at the cortical
Is the Fetus Conscious?
level, but in a system of highly convergent subcortical struc-
tures supplying the key mechanism of consciousness.” Electri- Attempts to set forth criteria for fetal consciousness create
cal stimulation of various cortical areas revealed that the difficulties of measurement and conundrums of proof and
reflective, conscious capacities of their patients proceeded in disproof. As the starting point for human observation of all
parallel with cortical stimulation effects such as elaborate fanta- natural phenomena, consciousness is required to construct
2
3. proofs of the existence of anything, but it is another matter to pain system thus uses the neural elements available during each
prove that consciousness is present.19 Fetal behavioral states stage of development to carry out its signaling role.
are frequently described in words such as “arousal,” “wake- Third, such reviews presuppose that cortical activation is
fulness,” or “awareness,” despite significant differences necessary for fetal pain perception.3,4,22 Based upon this as-
between these terms. sumption, the lack of evidence for pain-specific thalamocortical
Fetal sleep-like states can be inferred from EEG patterns connections supports their contention against fetal pain. This
or behaviors, implying an inhibition of cortical activity in utero, line of reasoning, however, ignores clinical data cited above that
mediated by cortical inhibitors such as adenosine, neurosteroids ablation or stimulation of the primary somatosensory cortex
(pregnenolone, allopregnenolone), corticotrophin-releasing does not alter pain perception in adults, whereas thalamic abla-
hormone, prostaglandins (prostaglandin D2), or a low blood tion or stimulation does. The thalamus plays a pivotal role in
oxygen.4 Conversely, high circulating levels of neurosteroids regulating the spinal-brainstem-spinal loops that mediate con-
such as dehydroepiandrosterone during fetal life may activate text-dependent descending facilitation or inhibition, coordinated
excitatory NMDA receptors, resulting in neuronal activation. via the key mechanisms underlying consciousness. Recent stud-
It remains unclear whether these hormonal changes are the ies have noted robust activation of the somatosensory cortex in
cause or consequence of fetal behavioral states. preterm neonates exposed to tactile or painful stimuli, modu-
In a careful analysis of fetal behavior that relies upon lated by gestational maturity, postnatal age, sex, laterality, and
memory and learning as the highest-order evidence for sleep/wake states.24,25
psychological function in utero, Hepper and Shahidullah
concluded that conscious sensory perception does occur in the The available scientific evidence
fetus.20 Can the fetus perceive pain from tissue injury? Abortion makes it possible, even probable,
or fetal surgery provoke robust behavioral and physiological that fetal pain perception occurs
responses not unlike the fetal responses to other aversive well before late gestation
stimuli.21
Conclusions
Closer examination reveals three major
The available scientific evidence makes it possible, even
flaws in the scientific rationale of recent probable, that fetal pain perception occurs well before late
reviews purporting to rule out the gestation. Those attempting to deny or delay its occurrence
occurrence of fetal pain must offer conclusive evidence for the absence of fetal pain at
given levels of maturity. When developmental time is translated
Critique of Recent Reviews across animal species to humans, it is clear that functionally
effective patterns of sensory processing develop during the
Closer examination reveals three major flaws in the second trimester. Thalamocortical interactions located in the
scientific rationale of recent reviews purporting to rule out the subplate zone persist into maturity, thus providing a functional
occurrence of fetal pain.3,4,22 First, pain perception is presented template for subsequent cortical processing. Several lines of
as mediated by a hard-wired system, passively transmitting evidence indicate that consciousness depends on a subcortical
nociceptive impulses until “perception” occurs in the system and that certain contents of consciousness are located in
somatosensory cortex.3,22 Pain research over the past 40 years, cortical areas. These subcortical structures, which develop much
beginning with the gate control theory and extended through earlier than the cortex, may play a pivotal role in sensory
vast amounts of clinical and experimental data, has long perception. Our current understanding of development provides
outgrown this Cartesian view of pain. Based upon this progress, the anatomical structures, the physiological mechanisms, and
we can assert with confidence that nociceptive signaling in the functional evidence for pain perception developing in the
prenatal development depends not only on the context and second trimester, certainly not in the first trimester, but well
characteristics of the stimulus, but also on the fetal behavioral before the third trimester of human gestation.
state at that time. For example, fetuses undergoing intrauterine
invasive procedures were reported to show coordinated
Acknowledgments
responses promoting the avoidance of tissue injury.21,23
Second, reviewers of this literature incorrectly assume that Comments and contributions from Barbara Clancy, Ph.D.
pain perception during fetal life must engage the same neural Associate Professor, Department of Biology, University of
structures as those used by adults. Lack of development of the Central Arkansas (Conway), Dr. Elie D. Al-Chaer, Associate
latter areas is then used to support the argument that fetuses do Professor of Pediatrics, Neurobiology and Developmental
not feel pain until late gestation. Clinical and animal research Sciences, UAMS College of Medicine; Dr. Bjorn Merker,
shows that the fetus or neonate is not a “little adult,” that the Professor of Psychology, Uppsala University (Sweden), and Dr.
structures used for pain processing in early development are R. Whit Hall, Associate Professor of Pediatrics, UAMS College
unique and different from those of adults, and that many of of Medicine, are gratefully acknowledged. This research was
these fetal structures and mechanisms are not maintained supported by the National Institutes of Health (NICHD: U10
beyond specific periods of early development. The immature HD50009-02; NCRR: P20 RR018765-02).
3