Limbic system Flashcards
Describe a way to find the amygdala.
Simple: Find fornix, go to hippo, at distal end of temporal lobe you’ll run into amygdala.
Complicated: Beneath the uncus of the limbic lobe, at the anterior end of the hippocampus and the inferior horn of the lateral ventricle.
What are the 3 major groups of nuclei in the amygdala?
Which is the biggest?
- Medial
- Central
- Basolateral (biggest)
What’s the role of the medial amygdalar nucleus?
Interconnected w/the olfactory system
small
What is the central amygdalar nucleus important for? Connections to what brain centers make this so?
Emotional responses/*visceral sensory input
- Hypothalamus + all brainstem (e.g. PAG)
What’s the main role of the basolateral amygdalar nuclei?
Key link of the experience of emotions and their expression.
What cortical area is the amygdalar basolateral nuclei closely associated w/?
Parahippocampal cortex
What general type of input do the amygdalar basolateral nuclei receive? (and from what 2 brain areas?)
What other part of the amygdala do they communicate w/?
- Sensory (from cortex and thalamus)
- Central nucleus
What type of cell would you find in the basolateral amygdalar nuclei that you’d also find in some layers of the cerebral cortex?
Pyramidal cells
Where do the basolateral amygdalar nuclei get their input from regarding sights, sounds, touches, smells, and tastes?
Thalamus + unimodal visual, auditory, somatosensory, and gustatory association areas
What 3 cortical areas do the basolateral amygdalar nuclei get their input from regarding levels of physical and emotional comfort and discomfort?
Orbital, anterior cingulate, and the insular cortices
Fibers leave the amygdala through the ______________ and the _____________ to reach many of the same areas that send afferents to it.
- Stria terminalis
- Ventral amygdalofugal pathway
Efferents from the amygdala to the thalamus primarily terminate in the:
a. Anterior nucleus
b. Dorsomedial nucleus
c. Lateral geniculate nucleus
d. Pulvinar nucleus
e. Ventral lateral nucleus
b. Dorsomedial nucleus
T/F - amygdala efferents can feed directly into the cortex. If false, what do they relay through?
True
Explain, in detail, the different functions of the amygdala.
- While hippo remembers event, amygdala remembers whether it was “good” or “bad”
- Triggers appropriate responses to help decide what to do (“gut feelings”) for future similar events
- Conditioned responses
- Fear response
Bilateral lesions to the tips of the temporal lobe would cause what syndrome?
Kluver-Bucy syndrome
What are the sx that characterize Kluver-Bucy syndrome?
- Docility
- Hyperorality
- Hyperphagia
- Visual agnosia
- Hypersexuality