18 - Limbic Systems

Question 1

what are the structures of the limbic system and their function?

Answer 1

olfactory cortex
hippocampal formation
amygdala
hypothalamus

Question 2

what is the function of the olfactory cortex?

Answer 2

olfaction

Question 3

what is the function of the hippocampal formation?

Answer 3

memory

Question 4

what is the function of the amygdala?

Answer 4

emotion and drives

Question 5

what is the function of the hypothalamus?

Answer 5

homeostasis; autonomic and neuroendocrine control

Question 6

what does the primary olfactory cortex receive direct input from?

Answer 6

the secondary sensory neurons without an intervening thalamic relay

Question 7

under the olfactory system, the anterior entorhinal cortex receives projections from the _____?

Answer 7

piriform cortex

Question 8

under the olfactory system, how does the piriform cortex project to the orbitofrontal olfactory area?

Answer 8

directly and indirectly via relays in the entorhinal cortex or in the mediodorsal nucleus of the thalamus

Question 9

what is the hippocampal formation comprised of?

Answer 9

dentate gyrus
hippocampus
subiculum

Question 10

in terms of the hippocampal formation, what is the dentate gyrus comprised of (three layers)?

Answer 10

moving inward from the pia, the molecular layer, granule layer, and polymorphic layer

Question 11

in terms of the hippocampal formation, what are the principal neurons of the dentate gyrus?

Answer 11

granule cells

Question 12

in terms of the hippocampal formation, what are the layers of the hippocampus and the subiculum?

Answer 12

same for both they are molecular layer, pyramidal layer, polymorphic layer

Question 13

in terms of the hippocampus formation, the principal neurons of the hippocampus and subiculum are the _____?

Answer 13

pyramidal cells

Question 14

what is the importance of the circuit of papez from the hippocampal formation?

Answer 14

for the cortical control of emotion and long term memory storage

Question 15

an important output is the projection from the _____ to the _____?

Answer 15

subiculum to the entorhinal cortex; an additional output pathway is the fornix which carries the outputs to the diencephalon and septal nuclei

Question 16

what are the important structures we learned associated with memory and the parahippocampal gyrus?

Answer 16

medial temporal lobe
medial diencephalic
basal forebrain

Question 17

what is the medial temporal lobe (MTL)?

Answer 17

hippocampal formation and adjacent cortex of the parahippocampal gyrus

Communicates with the association cortex via the entorhinal cortex

Question 18

what is the medial diencephalic memory areas (MD)?

Answer 18

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

Question 19

what is the basal forebrain?

Answer 19

Also plays a role in memory (primarily through its widespread cholinergic projections to cerebral cortex)

Question 20

what is declarative memory? name an example?

Answer 20

Involves conscious recollection of facts or experiences

amnesia (anterograde and retrograde)

Question 21

what is amnesia?

Answer 21

a type of declarative memory loss typical of bilateral MTL or bilateral MD lesions

Question 22

what is anterograde amnesia?

Answer 22

Deficit in forming new memories

Question 23

what is retrograde amnesia?

Answer 23

Loss of memories from a period of time before the brain injury

Question 24

what is non declarative memory?

Answer 24

Involves nonconscious learning of skills, habits, and other acquired behaviors

Question 25

where is the amygdala located?

Answer 25

a group of nuclei located in the anteromedial temporal lobe

Question 26

what are the three main nuclei of the amygdala?

Answer 26

basolateral nuclei
corticomedial nuclei
central nuclei

Question 27

what is the function of the basolateral nuclei?

Answer 27

Connections to diverse cortical areas, basal forebrain, medial thalamus

Question 28

what is the function of the corticomedial nuclei?

Answer 28

Olfaction, hypothalamus related appetite

Question 29

what is the function of the central nuclei?

Answer 29

Autonomic control

Question 30

what is the amygdala important for?

Answer 30

attaching emotional significance to various stimuli perceived by the association cortex

Question 31

what is the activity of the amygdala important for?

Answer 31

fear, anxiety, and aggression, whereas, activity in the septal area is important in pleasurable states

Question 32

both side ablation of amygdala causes?

Answer 32

placid behavior

Question 33

Reciprocal connections between the amygdala and hypothalamic and brainstem centers for autonomic control mediate changes?

Answer 33

heart rate, peristalsis, gastric secretion, piloerection, sweating, etc., changes commonly seen with strong emotions

Question 34

describe the reward center of the amygdala?

Answer 34

these are located along the course of the medial forebrain bundle, especially in the lateral and ventromedial nuclei of the hypothalamus

Question 35

describe the punishment center of the amygdala?

Answer 35

found in the central gray area surrounding the aqueduct of Sylvius in the mesencephalon and extending upward into the periventricular zones of the hypothalamus and thalamus.

Question 36

what are the three nuclei that comprise the amygdala?

Answer 36

corticomedial, basolateral, and central nuclei

Question 37

this structure is important for memory?

Answer 37

Parahippocampal cortex