The limbic system is a ring of structures located deep within the brain that is involved in emotion, motivation, learning, and memory. It includes the hippocampus, amygdala, hypothalamus, and other structures. The limbic system regulates behaviors related to survival like eating, drinking, and reproduction through reward and punishment centers. It also plays a role in emotions, memory formation, and decision making. Damage to limbic structures can impact behaviors, with lesions to areas like the hippocampus causing anterograde amnesia and lesions to the amygdala producing symptoms like the Kluver-Bucy syndrome.
The field of general sensory physiology is concerned with the principles underlying the sensory abilities of humans and animals. This general approach is possible and useful because the various sense organs closely resemble one another in organization and function, in their connections to centers in the brain, and in the reactions they elicit. Moreover, for all sense organs there is the problem of “objective” and “subjective” aspects. We can observe and analyze the performance of a human or animal sense organ by the same procedures as in research on the circulatory system, for example; in so doing, we are studying objective sensory physiology. But we can go further and apply scientific analysis to our own sensations, produced by environmental phenomena with the mediation of the sense organs, and in this we can also draw upon the analogous experiences reported by other people. Here we are in the area of subjective sensory physiology. One of the basic concerns in general sensory physiology is to analyze these two aspects and evaluate their interdependence.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
The Gram stain is a fundamental technique in microbiology used to classify bacteria based on their cell wall structure. It provides a quick and simple method to distinguish between Gram-positive and Gram-negative bacteria, which have different susceptibilities to antibiotics
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Adv. biopharm. APPLICATION OF PHARMACOKINETICS : TARGETED DRUG DELIVERY SYSTEMSAkankshaAshtankar
MIP 201T & MPH 202T
ADVANCED BIOPHARMACEUTICS & PHARMACOKINETICS : UNIT 5
APPLICATION OF PHARMACOKINETICS : TARGETED DRUG DELIVERY SYSTEMS By - AKANKSHA ASHTANKAR
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
2. LEARNIBG OBJECTIVES
• Brief physiological anatomy of limbic system.
• Describe the roles of limbic system.
• Discuss especially the roles of
– hippocampus
– amygdale
– various reward and punishment centers.
• Discuss the lesions of various parts of limbic
system,with neurophysiologic basis and
effects.
3. LIMBIC SYSTEM
• Limbic:border
• Refers to a ring of gray matter on the medial
aspect of the cerebral hemispheres.
4.
5.
6. LIMBIC SYSTEM
• the entire neuronal circuitry that controls
emotional behavior and motivational drives.
• Network of structures is associated with
emotions, basic survival and sociosexual
behavioral patterns, motivation, and learning.
7. Motivation
• is the ability to direct behavior toward specific
goals.
• Some goal-directed behaviors are aimed at
satisfying specific physical needs related to
homeostasis:Homeostatic drives
• As an example, the sensation of thirst,hunger.
10. Hypothalamus:
• Major part
• Vegetative roles
• Behavioral control
• governs the involuntary internal responses of various
body systems in preparation for appropriate action to
accompany a particular emotional state. For
example, the hypothalamus controls the increase of
heart rate and respiratory rate, elevation of blood
pressure, and diversion of blood to skeletal muscles
that occur in anticipation of attack or when angered.
• these preparatory changes in the internal state require
no conscious control
11. • Stimulation in the lateral hypothalamus :
thirst and eating, overt rage and fighting.
• Stimulation in the ventromedial nucleus and
surrounding areas mainly causes effects
opposite to those caused by lateral
hypothalamic stimulation—that is, a sense of
satiety, decreased eating, and tranquility.
12. • Stimulation of a thin zone of periventricular
nuclei, located immediately adjacent to the third
ventricle (or also stimulation of the central gray
area of the mesencephalon that is continuous
with, this portion of the hypothalamus), usually
leads to fear and punishment reactions.
• Sexual drive can be stimulated from several areas
of the hypothalamus, especially the most anterior
and most posterior portions of the hypothalamus
13. Effects Caused by Hypothalamic
Lesions.
• Bilateral lesions in the lateral hypothalamus :decrease drinking and
eating almost to zero, lethal starvation,extreme passivity of the
animal as well, with loss of most of its overt drives that are
observable emotional expressions (for example, laughing,
crying, or blushing).
• Bilateral lesions of the ventromedial areas of the
hypothalamus : excessive drinking and eating ,hyperactivity and often
continuous savagery (cruelty) along with frequent bouts of extreme
rage on the slightest provocation.
• Stimulation or lesions in other regions of the limbic
system, especially in the amygdala, the septal area,
and areas in the mesencephalon, often cause effects
similar to those elicited from the hypothalamus.
14. Anterior nucleus of thalamus
• Afferent connections:
– Mammillothalamic tract,cingulate gyrus and
hypothalamus
• Efferent connections:
– Cingulate gyrus,hypothalamus
• Functions:
– Emotional tone i-e attitude,mechanism of recent
memory.
15. Mamillary bodies
• They are connected to other parts of the brain
• act as a relay for impulses coming from
the amygdalae and hippocampi, via
the mamillo-thalamic tract to the thalamus.
• This circuit, from amygdalae to mammillary
bodies, and then on to the thalamus, is part of
the larger 'Papez circuit'.
16.
17. • Mammillotegmental tract: terminates in
reticular formation of mid brain.
• They, along with the anterior and dorsomedial
nuclei in the thalamus, are involved with the
processing of memory.
• They are believed to add the element of smell
to memories.
18. Dorsomedial nucleus of thalamus
• Prefrontal cortex,hypothalamus,other
thalamic
• Integration of somatic,visceral,olfactory
information and relation to subjective feelings
and emotional states
19. Damage to the mammillary bodies
• due to thiamine deficiency is implied in
pathogenesis ofWernicke-Korsakoff syndrome.
Symptoms include impaired memory, also
called anterograde amnesia.
• Lesions of the medial dorsal and anterior
nuclei of the thalami and lesions of the
mammillary bodies are commonly involved
in amnesic syndromes in humans.
20. Hippocampus
• The hippocampus and its adjacent temporal
and parietal lobe structures, all together
called the hipocampal formation.
• has numerous but mainly indirect
connections with many portions of the
cerebral cortex ,the amygdala, the
hypothalamus, the septum,and the mamillary
bodies
21. • Hyperexcitable:Prolonged discharges with slight
stimulus
• 3 layered structure
• Involved in sensations
– Almost any type of sensory experience causes
activation of at least some part of the hippocampus
– incoming sensory signals
– can initiate behavioral reactions for different purposes
22. • Seizures and hallucinations:focal epileptic
seizures with psychomotor effects
(olfactory,visual, auditory, tactile, and other
types of hallucinations that cannot be
suppressed as long as the seizure persists)
• pleasure,rage, passivity, or excess sex drive.
23. • Roles
– Learning(bilateral lesion,cant learn even names)
– Memory(working memory,consolidation of memory, declarative memory
functions)
– Evolutionary role (smell things to eat)
– Decision making for life and death
– It helps control corticosteroid production.
– It also has significant contribution to understanding spatial relations within
the environment.
• Lesion
– Anterograde amnesia
– No long term memory establishment.
– Lobes are removed for treatement of epilepsy.
24. Regions of the Amygdala
• Large basolateral region:
Provides direct input to basal ganglia and
motor system.
• Small corticomedial group of nuclei:
Related to olfactory cortex especially in
lower animals.
• Medial and central nuclei:
Connected to hypothalamus
31. • Involuntary movements
– (1) tonic movements, such as raising the head or
bending the body (2) circling movements (3)
occasionally clonic, rhythmical movements and (4)
different types of movements associated with
olfaction and eating, such as licking, chewing, and
swallowing.
• fear and punishment
• Sexual effects :erection(copulatory
movements, ejaculation, ovulation, uterine
activity, and premature labor).
32. Functions of the Amygdala
• behavioral awareness areas
• project into the limbic system one’s current status in
relation to both surroundings and thoughts.
• make the person behavioral response appropriate for each
occasion
• Relate environmental stimuli to coordinated behavioral
autonomic and endocrine responses seen in species-
preservation.
• Responses include:
Feeding and drinking
fighting behavior
Mating and maternal care
Responses to physical or emotional stresses
33. Kluver-Bucy Syndrome
• Results from bilateral destruction of temporal lobes or amygdala.
• Characteristics:
– Increase in sexual activity.
– Compulsive tendency to place objects in mouth.
– Changes in eating behavior.
– is not afraid of anything
– has extreme curiosity about everything
– forgets rapidly
– often has a sex drive so strong that it attempts to copulate with
immature animals, animals of the wrong sex, or even animals of a
different species.
• Although similar lesions in human beings are rare, afflicted people
respond in a manner not too different from that of the monkey.
34. Limbic cortex
• Cerebral association area for control of behavior.
• this ring of limbic cortex functions as a two-way
communication and association linkage between
the neocortex and the lower limbic structures.
• most poorly understood portion
• essentially all behavioral patterns can be elicited
by stimulation of specific portions of the limbic
cortex.
• ablation of some limbic cortical areas can cause
persistent changes in an animal’s behavior
35. Ablation of the Anterior Temporal
Cortex
• When the anterior temporal cortex is ablated
bilaterally, the amygdalas are almost invariably
damaged.
• Klüver-Bucy syndrome occurs.
36. Ablation of the Posterior Orbital
Frontal Cortex
• often causes an animal to develop insomnia associated with intense
motor restlessness, becoming unable to sit still and moving about
continuously.
• Function: The orbital frontal lobes act as the Senior Executive of the
social-emotional brain and exert tremendous inhibitory as well as
expressive influences on emotion and generalized arousal through
its massive interconnections with various limbic nuclie, the dorsal
medial nucleus of the thalamus and the reticular formation.
• When the orbital area is injured all aspects of emotional and
inhibitory behaviors may be compromised, and patients may display
disinhibition, manic-excitement, and internal utilization behaviors
(increased sexuality, orality).With complete destruction of the
orbital area, emotional and social functioning is abolished, but with
less extensive damage, rather than a loss of emotion there is a loss
of emotional control.
37. • cortical regions of the limbic system occupy intermediate
associative positions between the functions of the specific
areas of the cerebral cortex and functions of the subcortical
limbic structures for control of behavioral patterns.
• anterior temporal cortex: gustatory and olfactory
behavioral associations.
• In the parahippocampal gyri, there is a tendency for
complex auditory associations as well as complex thought
associations derived from Wernicke’s area of the posterior
temporal lobe.
• In the middle and posterior cingulate cortex, there is
reason to believe that sensorimotor behavioral associations
occur.
38.
39. Ablation of the Anterior Cingulate Gyri
and Subcallosal Gyri
• portions of the limbic cortex that communicate
between the prefrontal cerebral cortex and the
subcortical limbic structures.
• Destruction of these gyri bilaterally releases
the rage centers of the septum and
hypothalamus from prefrontal inhibitory
influence.
• Animal can become vicious i-e VIOLENT and much
more subject to fits of rage than normally.
40. Roles of prefrontal cortex
• higher levels of the cortex are also crucial for
conscious awareness of emotional feelings
• higher levels of the cortex, particularly the
prefrontal and limbic association areas, are
important in conscious learned control of innate
behavioral patterns
• prefrontal cortex formulates plans and guides
behavior, suppressing amygdala-induced
responses that may be inappropriate for the
situation at hand
41.
42. Medial forebrain bundle
• extends from the septal and orbitofrontal
regions of the cerebral cortex downward
through the middle of the hypothalamus to
the brain stem reticular formation.
• This bundle carries fibers inboth
directions, forming a trunk line
communication system between limbic system
and brainstem.
• Roles of reticular formation:mediate the
orders of hypothalamus,arousal.
43. • A second route of communication is through
short pathways among the reticular formation
of the brain
stem, thalamus, hypothalamus, and most
other contiguous areas of the basal brain.
44. Higer centers
• In executing complex behavioral activities such as
attack or mating, the individual must interact with the
external environment.
• Higher cortical mechanisms are called into play to
connect the limbic system and hypothalamus with the
outer world so that appropriate overt behaviors are
manifested.
• cortex provides the neural mechanisms necessary for
implementing the appropriate skeletal muscle activity
required to approach or avoid an adversary, participate
in sexual activity, or display emotional expression.
45. • Higher cortical levels also can
reinforce, modify, or suppress basic behavioral
responses so that actions can be guided by
planning, strategy, and judgment based on an
understanding of the situation.
46. Pathologies (lesions)
• Voracious appetite:very hungery
• Increased (perverse) sexual activity
• Docility:
Loss of normal fear/anger response,very calm
and easy to control
• Memory loss:
Damage to hippocampus portion
47. “Reward” and “Punishment” Function
of the Limbic System
• Electrical stimulation of certain limbic areas
• pleases or satisfies the animal or cause
terror, pain, fear, defense, escape reactions
• greatly affect the behavior of the anima
49. Reward Centers
• along the course of the medial forebrain
bundle
• lateral and ventromedial nuclei of the
hypothalamus.
• Less potent reward centers:
– the septum, the amygdala,certain areas of the
thalamus and basal ganglia, andextending
downward into the basal tegmentum of the
mesencephalon
51. Punishment Centers
• central gray area surrounding the aqueduct of
Sylvius in the mesencephalon and extending
upward into the periventricular zones of the
hypothalamus and thalamus.
• Less potent punishment areasare found in some
locations in the amygdala and hippocampus.
• Stimulation in the punishment centers can
frequently inhibit the reward and pleasure
centers completely.
52. Rage—Its Association with
Punishment Centers
• sudden and extreme anger
• Strong stimulation of the punishment centers
of the brain, especially in the periventricular
zone of the hypothalamus and in the lateral
hypothalamus, causes the animal to
53. Rage
(1) develop a defense posture,
(2) Extend its claws
(3) lift its tail
(4) hiss
(5) spit
(6) growl
(7) develop piloerection, wide-open eyes, and
dilated pupils.
54. Rage
• the slightest provocation causes an immediate
savage attack.
• expected from an animal being severely
punished.
55. rage phenomenon is held in check
mainly by
• ventromedial nuclei of the hypothalamus
• portions of the hippocampi and anterior
limbic cortex, especially in the anterior
cingulate gyri and subcallosal gyri, help
suppress the rage phenomenon.
57. Importance of Reward or Punishment
in Behavior
• Habituation Versus Reinforcement
– if the sensory experience does not elicit a sense of
either reward or punishment, repetition of the
stimulus over and over leads to almost complete
extinction of the cerebral cortical response.
ignores it.
– Reinforcement
• reward and punishment centers of the limbic
system select the information that we learn.
58. • Effect of Tranquilizers on the Reward or
Punishment Centers.
– chlorpromazine
59. Neurotransmitter Systems and the
Limbic System
• Dopamine: axons from ventral tegmental area
travel through the medial forebrain bundle and
connect with cingulate gyrus, hippocampus,
amygdala
• Serotonin: projections from the dorsal and median
raphe nuclei project diffusely and synapse on
limbic structures
• Noradrenergic system projects diffusely and
connects with limbic structures
• Cholinergtic system: projects diffusely and
connects with limbic system
60. • catecholamines are known transmitters in the
regions that elicit the highest rates of self-
stimulation in animals equipped with do-it-
yourself devices.
• Drug of abuse: Many abused drugs act by
enhancing the effectiveness of dopamine in the
“pleasure” pathways
– Amphetamine stimulates the release of dopamine
from dopamine-secreting neurons.
– is cocaine, which blocks the reuptake of sdopamine at
synapses
61. • A functional deficiency of serotonin or
norepinephrine or both is implicated in
depression
• Serotonin and norepinephrine are synaptic
messengers in the limbic regions of the brain
involved in pleasure and motivation
62. schizophrenia
• Various addictive compounds affect activity of the
dopamine transmission in the nucleus accumbens that is
ventral striatum or (mesolimbic) and frontal cortical
(mesocortical) systems.
• Additionally, these pathways appear to be functionally
unbalanced in patients with schizophrenia. It appears that
patients with schizophrenia have diminished dopamine
effects through mesocortical systems to the prefrontal
cortex. This could produce symptoms such as social
withdrawal and diminished emotional responsiveness.
Concurrently, there is a relative increase in dopamine
effects via the mesolimbic system to the ventral striatal
system, resulting in positive symptoms of delusions and
hallucinations.
65. • The hypothalamus plays an important role in generating
emotional behaviors…but
• The amygdala has been implicated in playing a prominent role in
integrating information and coordinating emotional behaviors in
response to sensory stimuli, events, and memories. These
findings were demonstrated in:
– Fear conditioning studies in rodents
– Monkey studies (Kluver-Bucy)
– Human neuroimaging and lesion studies
– Studies of memory modulation by hormones in lower animals.
66. • Reward processing occurs in distinct brain circuits.
– Stimulation of these circuits can provide powerful
reinforcement signals.
– Dopaminergic neurons in the ventral tegmental area provide a
learning signal that reflects a computation comparing the
reward received to the reward expected.
– Drugs of abuse act on reward circuits.
• Psychiatric disorders such as depression, anxiety disorders, and
addiction, all involve limbic system neural circuitry.