Limbic system

autonomic nervous system

divided into parasympathetic and sympathetic nervous system “rest and digest” “fight or flight”

what is the ans responsible for

fighting, feeding, fleeing, and fornication

controls the viscera

part of nerves responsible for parasympathetic

craniosacral

part of nerves responsible for sympathetic

thoracolumbar

parts of the limbic system

hypothalamus (mammillary bodies), hippocampus, amygdala, limbic cortex

hypothalamus

collection of nuclei with control over autonomic nervous and hormone secretion

hippocampus

consolidation of memory and spatial memory

→ input from the entorhinal cortex

→ outputs through fimbra, fornix to hypothalamus

neurogenesis

new cells are born in the dentate gyrus of the hippocampus throughout life.

amygdala

fear, rage and aggression, and sexual behavior

input of the the amygdala

hippocampus, entorhinal cortex, sensory thalamus and cortex, viscero-sensory cortex, sensory brainstem, polymodal association cortex.

output of the amygdala

HPA axis, modulatory system, freezing, sympathetic and parasympathetic NS, prefrontal cortex, ventral striatum, polymodal association cortex

central

low road

• central (faster, autonomic)

• lower level sensory input

• output to autonomic nervous systems and modulatory systems

basolateral

high road

• slower, cognitive

• inputs from hippocampus, association cortex, thalamus,

• outputs to medial prefrontal cortex, association cortex, ventral striatum/nucelus accumbens

Korsakoff Syndrome

Caused by thiamine defiiciency, most commonly in alcoholism

Damage to mammillary bodies and limbic thalamus

Amnesia and confabulation

toxoplasmosis

parasite that lives in cat guts

infects the amygdalae of rats and makes them unafraid of cat…dangerous to fetus if infected

Kluver-Bucy Syndrome

Bilateral lesions of medial temporal love can lead:

• Hyperphagia

• hypersexuality, indiscriminate mating

• docility

• amnesia