Hypothalamus and Limbic System

Where is the hypothalamus located?

In diencephalon; inferior to thalamus

Function of the hypothalamus

Homeostatic regulation: endocrine and autonomic control

What are symptoms of lesions in the hypothalamus?

Hyper/hypo-thermia (temp regulation)

Diabetes insipidus (water balance; lack of ADH)

Over/under eating (satiety)

Rage (emotion)

Circadian rhythm

What does the limbic system do?

Areas of brain that controls emotion and behavior through outputs to ANS via the hypothalamus

What are the components of the limbic system?

Amygdala, hippocampus, orbitofrontal cortex (smell), hypothalamus

Sometimes thalamus, nucleus accumbens (rewards), limbic lobe

Amygdala

Rostral to hippocampus

Fear, rage, feeding behaviors

Connects to hypothalamus via fornix

Input from all sensations

Lesion of the amygdala

Lack of fear and poor emotional learning only if B

Hippocampus

Near medial temporal lobe in horn of lateral ventricles

Learning and memory (converts short term to long term memory)

Lesion of the Hippocampus

B = anterograde amnesia (cannot create long term memory but can recall long term memory)

Nucleus accumbens

In ventral striatum

Reward center for pleasure and motivation using dopamine (addiction)

Kluver-Bucy Syndrome

B damage to medial temporal lobe (includes amygdala and hippocampus)

Symptoms of Kluver Bucy Syndrome

Placid, hyperphagia, visual agnosia (cannot recog items), fearless, hypersexual, retro and anterograde amnesia

Korsakoff Syndrome

Caused by chronic alcoholism and B1 deficiency; damage to mammillary bodies and mediodorsal thalamus

Symptoms of korsakoff syndrome?

Amnesia, confabulation (recalling false memories