To understand some of the advanced concepts in Fetal Pain, you must first have an understanding offetal pain basics. Three components are necessary for establishing the presence of fetal pain. First, thenecessary structures, which include nociceptors, nerve pathways and the thalamus. Second, function,established through electrical, neurotransmitter or hormonal activity and finally, observation of anaversive response to a noxious stimulus.In addition, one needs to understand evolutionary concepts of pain development and how they favorearly development of pain sensation and response. One of the theories associated with evolutionarydevelopment is that "Ontogeny recapitulates phylogeny". This is known as the recapitulation (or briefrepetition) theory. Ontogeny is the growth and development of an individual organism – for example,the human embryo; phylogeny is the evolutionary history of a species. Haeckel, who formulated therecapitulation theory, claims that the changes in size and shape that constitute growth anddevelopment of advanced species passes through stages represented by adult organisms of moreprimitive species. Otherwise put, each successive stage in the development of an individual representsone of the adult forms that appeared in its evolutionary history. Even more simply the development ofthe individual repeats the evolution of the race. A corollary to Haeckel’s theory is that primitive functionalabilities, possessed by the more primitive evolutionary species, appear at the time those evolutionarystages appear.How does this apply to human fetal pain theory? Well, one of the earliest “stages” of fetal developmentis the Fish stage. Well, fish feel pain. In a 2003 study, researchers from the University of Edinburgh shotbee venom into the lips of trout. The bee-stung fish rubbed their lips in the gravel of their tank andgenerally demonstrated aversive behavior. The researchers, led by Dr Lynne Sneddon, say the"profound behavioural and physiological changes" shown by the trout after exposure to noxioussubstances are comparable to those seen in higher mammals. They investigated the fish for thepresence of nociceptors, sites that respond to tissue-damaging stimuli and found an extensive array ofsuch receptors. These polymodal receptors are the first to be found in fish, and resemble those inamphibians, birds and mammals, including humans. The research, by a team from the Roslin Institute, ispublished in Proceedings B of the Royal Society, the UKs national academy of science.There is a new study out that also contends fish feel pain. A professor at Purdue and his Norwegiangraduate student attached small foil heaters to goldfish. In the (2009) Journal - Applied AnimalBehavior Science, Purdue University Assistant Professor Joseph Garner and Janicke Nordgreen, adoctoral student in the Norwegian School of Veterinary Science performed the research where half ofthe goldfish were injected with morphine, half with saline, and then the researchers turned on theattached micro-heaters. After the heat was gone, the fish without painkillers "acted with defensivebehaviors, indicating wariness, or fear and anxiety." This indicates that the fish consciously perceivepain in the test and had memory for the pain.Before the 2003 and 2009 research, opponents cited the work of Dr. James Rose, a professor of zoologyand physiology at the University of Wyoming. He wrote a paper in 2002 debunking the idea thatexperiments such as injecting fish with bee venom and then observing their behavior leads to anyreasonable conclusions about fish pain. He argues that fish dont have the neurological capacity toexperience the "psychological aspect" of pain. They react to pain, but they cannot mentally process"pain" when painful things happen to them. Its the human observer who puts these mental states onthe fish. The 2009 fish study effectively debunked his assertions.
The 2003 and 2009 studies show fish are able to form sensory memories. For instance, trout canremember how to avoid getting caught in fishing nets months after the initial experience, memories of itstick in their brains.Scientific American stated: New research suggests that (fish) may feel and remember pain, revealingthat their nervous system may be more complex than we thought—and our own awareness of pain maybe much more evolutionarily ancient than suspected.Which leads us into our next topic, which is the question of fetal consciousness versus instinct orreflex. Instinct or innate behavior is the inherent inclination of a living organism toward a particularbehavior. The simplest example of an instinctive behavior is a fixed action pattern, such as a birdbuilding a nest, in which a short sequence of actions, without variation, are carried out in response to aclearly defined stimulus. An early researcher on instinct, Fabre, considered instinct to be any behaviorwhich did not require cognition or consciousness to perform. Freudian Psychoanalysts have stated thatinstinct refers to human motivational forces (such as sex and aggression) outside of our control or abilityto alter.A simple definition of consciousness is sensory awareness of the body, the self, and the world. I wouldgo beyond that to say some level of consciousness must be present if one is capable of remembering oraltering behavior in response to changes in the environment. Such decision-making must take place at ahigher level than mere reflex.Several studies suggest that children can learn while they are still in the womb. For example, newbornsprefer the sound of their own mothers voice. In one experiment, they learned to change their patternof sucking in order to activate a recording of their mothers voice instead of that of another woman. Thepreference appears to have been acquired before birth.In another case, newborns preferred the sound of their mothers voice when it was adjusted toresemble what they might have heard in the womb. In an even more amazing study, newborns stoppedcrying and responded to songs played on shows that their mothers watched while they were pregnant.Prenatal learning seems to extend to the sense of taste as well. Mothers who maintained the same dietbefore and after they gave birth were more successful in breastfeeding than mothers who changed to aless spicy diet. This may reflect the childs preference for food the mother ate while she was pregnantbecause the mothers milk contains clues about her diet.Even the olfactory system in the womb is functional from the second month onwards, and the baby cannot only taste the food that you have eaten, but also smell it by its fragrance in the amniotic fluid.Assertions of fetal consciousness seem to center around the 20th week and certain events occur aroundthis time that favors this belief.At 20 weeks, the fetal brain has the full complement of neurons present in adulthood. Lagercrantz H et. al. Lakartidningen 1991;88:1880-85 (Ranalli)
By 19-20 weeks, the earliest electroencephalogram (EEG) recordings are possible. Flower MJ. J Med Philos 1985;10:237-251 (Ran)From 20 weeks and beyond, the fetus is fully capable of experiencing pain. Expert testimony from Dr. Robert White, pediatric neurosurgeon, before U.S. Congress,June 15, 1995 (Ran)Opioid receptor labeling in the brain stem of fetuses at 19-21 weeks gestation demonstrate very highdensities in supraspinal centers associated with sensory perception. These inhibitory opioid receptorsmay be the only protection for the developing neuronal systems from constant over stimulation, giventhe overall underdeveloped gate control mechanism in the dorsal horn of the spinal cord. (Wright)And the physical response to painful stimuli by unborn children undergoing fetal surgery can be blockedby the administration of fentanyl, a potent narcotic.The eyelids start opening at around 20 weeks gestation and the child can perceive light from outside.In a 1998 article by Wade, the author asserted:In recent years, prenatal research has demonstrated that fetuses are far more sophisticatedthan previously thought, findings generally ignored by the medical and psychologicalestablishment in part because the neurological structures traditionally associated with mentationwere not believed to be functional. Recent research on memory suggests that consciousnessmay not be dependent on the central nervous system, or even on the body. Using each majortheory of memory and neurological research to examine the prenatal data, this paper concludesthat two sources of consciousness are present before and during birth constructing a singlesubjective experience of self.Also see “Changes of Mind: A Holonomic theory of the evolution of Consciousness”By 18 weeks, or as Aquinas would say, quickening, purposeful movements of the unborn child are aregular occurrence. These include positioning within the womb, preference for handedness, includingthumb sucking, and activity against the external environment. We know categorically that full bodysensation and response is present in all limbs, including a memory component. How can this be? Simplyput, due to the lack of self-harm.While this concept may seem difficult at first, consider for the moment the diabetic - or any patient withperipheral neuropathy. The lack of sensation in lower legs and feet regularly results in injury, often
associated with severe trauma, but without the awareness of injury. The end result can be infection,amputation and even death. But despite the jumps, bumps and pounding associated with quickening,we see no intrauterine injury. No maceration or deformity of limbs. The lack of these injuries implies atleast some degree of intrauterine sensation and activity modulation, including primitive memory. Myhat is off, therefore, to Thomas Aquinas, The FATHER of fetal pain.Not all science is supportive of these concepts. In a study of EEG patterns in foetal sheep it was alleged:“Consciousness appears for the first time after birth. We conclude the embryo and foetus cannot suffer before orduring birth. Suffering can only occur in the newborn when the onset of breathing oxygenates its tissues,” Mellorsaid. Since the fetus is oxygenated throughout the time in the womb, how does the brain know that the oxygen itis getting comes from it’s own lungs and not from the placenta? No explanation is provided. And if the fetus isindeed in a sleep state, as some claim, then what is quickening? – The earliest example of restless leg syndrome?Finally, we need to consider genetic aspects of development and the importance of the pain response.In an article on Genetic Influences on Pain Perception and TreatmentAlyson Fincke stated quote:From a Darwinian perspective, nociceptive pain is impossible to eliminate nor is it desirable to do so.Nociception is essential for survival and, if a variation in a pain mechanism gene alters the function of anociception-related molecule, the survival rate would be diminished. For instance, without painmechanisms, people would not recognize the danger of leaving their hand on a hot stove. Mutationsleading to decreased pain sensitivity occur in well under 1% of the population and lead to frequentinjuries and inadvertent self-mutilation, which are incompatible with longevity or transmission tooffspring. The limited number of individuals who have this mutation makes it difficult to produce astrong study, as that would require a large number of participants. While it is necessary to perceive painfrom a survival standpoint, we must strive to manage pain pathways when they go awry and fire in theabsence of noxious stimuli.Even with that basis, there are significant differences in individual pain sensation and response. Forexample, A person’s level of the enzyme catecholamine-O-methytransferase (COMT)—the enzyme thatcontrols levels of adrenaline, noadrenalin and dopamine—is an indicator of how sensitive that individualis to painful stimulation. Humans’ genetic variants of COMT fall into one of three variations that givethem high, average or low pain sensitivity.And among other genetic oddities, redheads have been shown to be more sensitive to pain thanaverage, often requiring 20% more anesthetic to reach the same level of pain relief.And in the latest research on the genetic origins of painfrom:http://www.anaesthetist.com/icu/pain/Findex.htm#pain3.htmProbably the most significant discovery ever in the field of pain hasbeen the gene c-fos. The cellular analogue of a viral oncogene (cancer),
this rather special gene and its cellular product, the protein called Fosseem crucial to the profound central nervous system changes thatoccur when an animal (or man) feels pain. Central nervous system c-fosexpression correlates extremely well with painful stimulation.Generically, Fos is one of the inducible transcription factors (ITFs) thatcontrols mammalian gene expression.We now have a molecular marker for pain! Even more important, weknow that because c-fos is a proto-oncogene - that is, it can promotevast intracellular changes including cellular restructuring andproliferation - it is almost certainly involved in the long-termneurological consequences of noxious stimulation.An incidental note - FOS has been found in the fetal bones at least asearly as the 16th week of gestation.