Parts of the Limbic System - lecture 7 Flashcards
where is the amygdala
little almond shaped structure
deep inside the antero-inferior region of the temporal lobe
what does the amygdala connect
hippocampus, the septal nuclei, prefrontal area and the medial dorsal nucleus of the thalamus
what do the connections of the amygdala allow
the amygdala to play its role
role of the amygdala
mediation and control of major affective activities
ex: friendship, love and affection, expression and mood, fear, rage, aggression
what is the amygdala fundamental for
self preservation
b/c it is the center for identification of danger
what input does the amygdala recieve
sensory input
highly processes input to recognize the elements of a scene that signal danger
main inputs to the amygdala
visual, auditory and somatosensory cortices
amygdala outputs
must be able to control the autonomic system
provoke an instant sympathetic response
main outputs of the amygdala
hypothalamus and brainstem autonomic centers
how is the amygdala divided
into 3 groups of subnuclei
3 groups of subnuclei
large basolateral (ventrolateral)
small corticomedial
central
large basolateral receives
receives afferent fibers
small corticomedial receives
receives afferent fibers
central
sends efferent fibers
corticomedial nucleus
oldest phylogenetically
what is the corticomedial nucleus
termination of olfactory info from the olfactory bulb and cortex
how does the corticomedial nucleus project
projects to ventromedial nucleus of hypothalamus
plays a role in eating behaviors
basolateral nucleus
newest phylogenetically
what is the basolateral nucleus connected to
cortical sensory association areas from all lobes
how does the basolateral nucleus project
to thalamus and the ventral striatum
what does the basolateral nucleus influence
hypothalamic fxns associated w/ feeding and drinking behavior, autonomic and somatic reflexes and responses to stress
what projects to the central nucleus
basolateral and corticomedial nuclei
what does the central nucleus have connections to
reciprocal connections with the visceral sensory and visceral motor nuclei
located in the brainstem
what does the central nucleus give rise to
ventral amygdalaofungal pathway
ventral amygdalofungal pathway
terminates in the ANS nuclei of the brainstem
what does the amygdalofungal pathway include
dorsal motor nucelus of the vagus
nuclei of reticular formation involved in respiratory and CV fxns
what does destruction of both amygdalas lead to
tames the animal
sexually non-discriminative
deprived of affection and indifferent to danger
what does the electrical stimulus of the amygdala elicit
crises of violent aggressivity
humans w/ marked lesions on the amygdala
loose the affective meaning of the perception of any outside info
where is the cingulate gyrus
medial side of the brain
b/w the cingulate sulcus and the corpus callosum
what is the cingulate gyrus
principle fiber bundle connecting the 2 cerebral hemispheres
what does the frontal part associate with
smells and sights with pleasant memories of previous emotions
participated in emotional reaction to pain and in the regulation of aggressive behavior
what happens if the cingulate gyrus is cut
reduces pre-existent depression and anxiety levels
what is the septal nuclei
evolutionary and developmental outgrowth of the hippocampus and the hypothalamus
what does the septal nuclei link
the hippocampus with the hypothalamus as well as the brainstem
what does the septal nuclei consist of
both lateral and medial segments via interconnections
what does the septal nuclei exert
modulatory influences on the hippocampus in regard to memory fxn and arousal
what else is the septal nuclei interconnected to
amygdala
for hypothalamic activity and emotional and sexual arousal
ventral tegmental area of the brainstem
just below the thalamus
what does the ventral tegmental area consist of
dopamine pathways
responsible for pleasure
damage to ventral tegmental area
difficulty getting pleasure in life
often turn to alc, sweets, drugs and gambling
where do the basal ganglia lie
over the sides of the limbic system
tightly connected with the cortex above them
what are the basal ganglia responsible for
repetitive behaviors
reward experiences
focusing attention
prefrontal cortex
lies in front of the motor area
part of the frontal lobe
what is the prefrontal cortex involved with in the limbic system
same dopamine pathways as the ventral tegmental areas
plays a part in pleasure and addiction
