18 - Limbic Systems Flashcards
what are the structures of the limbic system and their function?
olfactory cortex
hippocampal formation
amygdala
hypothalamus
what is the function of the olfactory cortex?
olfaction
what is the function of the hippocampal formation?
memory
what is the function of the amygdala?
emotion and drives
what is the function of the hypothalamus?
homeostasis; autonomic and neuroendocrine control
what does the primary olfactory cortex receive direct input from?
the secondary sensory neurons without an intervening thalamic relay
under the olfactory system, the anterior entorhinal cortex receives projections from the _____?
piriform cortex
under the olfactory system, how does the piriform cortex project to the orbitofrontal olfactory area?
directly and indirectly via relays in the entorhinal cortex or in the mediodorsal nucleus of the thalamus
what is the hippocampal formation comprised of?
dentate gyrus
hippocampus
subiculum
in terms of the hippocampal formation, what is the dentate gyrus comprised of (three layers)?
moving inward from the pia, the molecular layer, granule layer, and polymorphic layer
in terms of the hippocampal formation, what are the principal neurons of the dentate gyrus?
granule cells
in terms of the hippocampal formation, what are the layers of the hippocampus and the subiculum?
same for both they are molecular layer, pyramidal layer, polymorphic layer
in terms of the hippocampus formation, the principal neurons of the hippocampus and subiculum are the _____?
pyramidal cells
what is the importance of the circuit of papez from the hippocampal formation?
for the cortical control of emotion and long term memory storage
an important output is the projection from the _____ to the _____?
subiculum to the entorhinal cortex; an additional output pathway is the fornix which carries the outputs to the diencephalon and septal nuclei
what are the important structures we learned associated with memory and the parahippocampal gyrus?
medial temporal lobe
medial diencephalic
basal forebrain
what is the medial temporal lobe (MTL)?
hippocampal formation and adjacent cortex of the parahippocampal gyrus
Communicates with the association cortex via the entorhinal cortex
what is the medial diencephalic memory areas (MD)?
Thalamic mediodorsal nucleus, anterior nucleus of the thalamus, internal medullary lamina, mammillary bodies, and other diencephalic nuclei lining the third ventricle
communicates with the MTL through several unnamed systems
what is the basal forebrain?
Also plays a role in memory (primarily through its widespread cholinergic projections to cerebral cortex)
what is declarative memory? name an example?
Involves conscious recollection of facts or experiences
amnesia (anterograde and retrograde)
what is amnesia?
a type of declarative memory loss typical of bilateral MTL or bilateral MD lesions
what is anterograde amnesia?
Deficit in forming new memories
what is retrograde amnesia?
Loss of memories from a period of time before the brain injury
what is non declarative memory?
Involves nonconscious learning of skills, habits, and other acquired behaviors
