Limbic System Flashcards
(29 cards)
Where is the olfactory epithelium?
superior conchae
Where does the olfactory tract go to?
The anterior perforated substance and the entorhinal cortex (they can also project to the amygdala and hypothalamus). They then project to the thalamus and ends up in orbitofrontal and insular cortex.
What is the function of the lateral descending projections
elicit specific behaviors
What is the function of the medial descending projections?
help support and modulate the behaviors
Describe the Papez Circuit
1) Neocortex (inputs)
2) cingulate cortex
3) Hippocampus
4) Hypothalamus (output)
5) anterior nuclei of the thalamus
6) back to the cingulate cortex
How was Papez circuit incorrect?
1) the hippocampus does NOT communicate with the hypothalamus
2) The amygdala is a key player in emotional expression
3) also left out the orbital and medial PFC
What is a lesion in the amygdala going to look like?
Cannot be conditioned to fear, but can acquire explicit knowledge
What will the result of a hippocampal lesion be?
Can develop a fear response, but can’t learn explicit knowledge
What will be the result of a lesion that affects both the amygdala and the hippocampus?
Neither fear condition or explicit knowledge were displayed
Which part of the cingulate cortex is involved with the limbic circuitry?
Anterior (and middle)
What is the role of the amygdala in the limbic system
Output–> plays a critical role in negative emotions (esp fear)
What region might serve as a conduit between the cognitive functions of the prefrontal cortex and the emotional experiences of medial temporal limbic systems?
anterior cingulate cortex
What region of the limbic system is associated with sadness?
anterior cingulate system
What is Kluver-Bucy syndrome?
Lack of fear in the presence of previously fearful stimuli (amygdala lesion)
What is psychic blindness?
The absence of an appropriate behavioral response to fear-eliciting stimuli (the cognitive processing of emotional stimuli was altered)
Besides mediating the fear response, what are the functions of the basolateral amygdala?
negative and positive emotional experiences as well as spatial and motor learning
Where does the basolateral amygdala receive input from?
cerebral cortex, thalamus, and hippocampus
Where is the amygdala in regard to the hippocampus?
anterior to it
Both are in the medial aspect of the temporal cortex
What are the parts of the true limbic system?
1) cerebral cortex–> orbital and medial PFC, anterior cingulate cortex, and amygdala (output)
2) hypothalamus (PVN)–> output
3) Basal ganglia–> ventral striatum (ventral pallidum and N. accumbens)
4) Thalamus–> MD nucleus (connects striatum to the cortex)
What are the 3 basic components of emotional response?
1) autonomic/ visceral
2) somatomotor
3) internal feelings
which part of the limbic system allows for Duchenne’s smile?
the cingulate cortex
What are the two major output pathways of the emotional brain?
The amygdala and the hypothalamus
How does the hypothalamus maintain homeostasis?
1) activating the autonomics
2) HPA axis
What is the major descending pathway from the PVN (hypothalamus)?
Dorsal longitudinal fasciculus (DFL)
