1. Hypothalamus And Limbic System
ANHB 2217 – 2006
Avinash Bharadwaj

2. Hypothalamus A small area with great activity Crossroads :
Somatic and visceral activity
Emotion and responses
Olfaction, memory and responses
Short- and long control loops
“Preservation”
Feeding
Hunger and satiety
Defence
Somatic and visceral activity
Reproduction
Sex drive and autonomic responses
Homoeostasis
Temperature and osmolar regulation

3. Hypothalamus : Topography
Column of fornix
Paraventricular
Anterior
Supraoptic
Posterior
Dorsomedial
Ventromedial
Mamillary body
Medial Zone
Pituitary

4. Connections Efferent Autonomic nuclei – brainstem, spinal cord
Striated muscle :
Brainstem + Spinal motor neurons (feeding / shivering…)
Mamillary body  thalamus   cingulate gyrus – memory, visceral expression of emotion
Mamillary body  brainstem reticular formation
? Higher mental function through cortex
Afferent
Somatic and visceral information
Olfactory areas
Emotional / olfactory : amygdaloid nucleus
Hippocampal input via fornix – mamillary body
Cerebral cortex (esp. orbital cortex

5. Some Functional Correlations
Problems in Studying…
Indistinct nuclear boundaries
Tracts and nuclei – crisscross
Imprecise experimental / clinical lesions
Some Functional Correlations
Clinical / experimental
Anterior / preoptic : parasympathetic
Posterior / lateral : sympathetic
Temperature sensors – vasodilation and sweating OR constriction and shivering.
Hunger and satiety centres : blood glucose, visceral afferents, smell, limbic inputs
Intrinsic sensors

6. The Pituitary Connection – 1PV SO A P
Vasopressin (ADH)
Oxytocin
Large neurons (magnocellular)
Peptides and neurophysins
Herring bodies
Cleavage and release A

7. The Pituitary Connection – 2
“Adenohypophysis”
Target gland hormone levels…
Small neurones (parvocellular)
Releasing factor (hormone)
Blood vessels
Portal system A

8. Summary Weaving together Autonomic and endocrine controls Homeostasis
Higher centres

9. Limbic System Limbic lobe and limbic system “Limbus”
Lobe : hippocampus, PHG, cingulate gyrus
System : Also includes Dentate gyrus, amygdaloid, septal area, mamillary bodies, thalamic nuclei

10. Limbic System Cingulum and cingulate gyrus Fornix Ant nucl thalamus
Mamillary body
Fornix
Ant nucl thalamus
Mamillary body
Hippocampus
Dentate gyrus
Parahippocampal gyrus
Amygdala

11. Hippocampus

12. Limbic System Memory Emotion “Preservation” The olfactory connection
Visceral responses
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