Lecture 5: Understanding the Telencephalon and the Amygdala's Role in Behavior and Emotion

which of following are part of telencephalon

a. lateral ventricles

b. corpus callosum

c. deep subcortical nuclei (basal ganglia)

d. cerebral cortex

all are true

basal ganglia - 3 nuclei made up of

caudate , putamen & globus pallidus

basal ganglia

project to motor areas of cortex & play important role in motor system

- damage here results in loss of movement as in Parkinsons disease

amygdala

adj to hippocampus

functions: arousal, endocrine, emotions, autonomic responses related to fear

* deep in temporal lobe

functions hippocampus

functions : memory (forming, storing, retrieving) , spatial navigation, limbic (connecting emotions & senses, such as smell & sound, to memories)

looks like seahorse

which structure is found in telencephalon & controls aggression & fear responses

a. basal ganglia

b. amygdala

c. mammillary body

d. reticular formation

e. hippocampus

b. amygdala

which fiber bundle connects hypothalamus to hippocampus

a. fornix

b. anterior commissure

c. stria terminalis

d. internal capsule

e. mammillary body

a. fornix

functions of amygdala

fear (arousal responses) , attention, reward behavior, emotional memory

lesions in amygdala

deficits in ability to assess danger ; reduce fear & aggression ; monkeys lose rank in social hierarchy

electrical stimulation in amygdala

done in cats

- produce repeated defense reactions (physiological changes, defensive attack, retreat)

disorders from amygdala

anxiety disorders (panic attacks, social phobias) , autism , OCD

in which conditions would you expect amygdala to be activated

a. anxiety (panic) attacks

b. PTSD

c when confronted by snarling pit bull

d. social phobias

e. all of above

all of above

is amygdala part of the limbic system

yes bc its role in emotions

limbic system

on medial walls of brain form ring around brain stem & corpus callosum ; cingulate gyrus, medial temporal cortex, amygdala, hypothalamus , hippocampus

papez circuit

papez believed that emotional experience was determined by activity in cingulate cortex (amygdala, AMG)

- emotional expression (behavior) was thought governed by hypothalamus

- to store memories (emotional coloring ) cingulate cortex projects to hippocampus, which projects to hypothalamus by way of fornix

- hypothalamic effects reach the cortex via relay in anterior thalamic nuclei & brainstem for physiological responses

damage to limbic system

reduced aggression & relief from fear

bilateral damage to amygdala kluver bucy syndrome

- reduced fear & agression

- oral tendencies due to poor visual recognition

-disordered personality --> blunted or "flattened" emotions

- hypersexulaity

clinical treatment using lesions for limbic system

temporal or frontal lobectomy or amygdalectomy performed by cutting conx w/ prefrontal corte

- still in use to treat severe aggression & violent behavior

What connects hypothalamus to amygdala?

Stria Terminalis