Limbic System

Question 1

the ______ portion of the limbic system is involved in emotion and includes the olfactory system, insula, amygdala, anterior cingulate cortex, and parts of the (subgenual) medial frontal cortex

Answer 1

rostral

Question 2

the _____ portion of the limbic system is involved in memory and visuospatial function, and includes the parahippocampal gyrus, hippocampus, and posterior cingulate cortex

Answer 2

caudal

Question 3

the limbic system does not receive direct input from the thalamus, with one exception - what is it?

Answer 3

the insula does receive visceral/taste inputs and “emotional” pain inputs from thalamic relays

Question 4

Which of the following is NOT a characteristic of the limbic cortex?

A. It is largely agranular
B. It receives mostly direct sensory input from the thalamus
C. It receives multimodal sensory input from primary and association cortices and via non-specific/association thalamic nuclei
D. It targets the nucleus accumbens in the ventral striatum, participating in loop circuits involving appetitive motor behavior
E. All areas are heavily interconnected, mainly via the cingulum and uncinate fasciculus

Answer 4

B. The limbic system mostly does not receive direct sensory input from the thalamus, with the exception of the insula, which receives visceral afferent/taste input, as well as emotional pain inputs directly from thalamic relays.

Question 5

the olfactory tract divides caudally on its way toward the brain, into medial and lateral olfactory striae. Where do these two branches terminate?

Answer 5

The medial striae terminate in either the septal region below the rostrum of the corpus callosum, or the ant. hypothalamus/commissure.
The lateral striae terminate in the primary olfactory cortex (uncus)

Question 6

Taken together, the uncus, amygdala, and the anterior parahippocampal gyrus are referred to in human anatomy as the _____ cortex, with shared functions relating to olfaction.

Answer 6

piriform

Question 7

this structure is considered the “sensory cortex” of the limbic system

Answer 7

insula

Question 8

this area in the midbrain receives ascending pain inputs, important for generating a complex of defensive behaviors, as well as pain modulation

Answer 8

periaqueductal gray (PAG)

Question 9

with respect to pain centers, which of these is matched incorrectly?

A. Amygdala - direct viscerosomatic pain signals
B. Short gyri of insula - dull and poorly localized visceral pain
C. Precentral gyrus - somatotopic location of somatic pain
D. Periaqueductal gray (PAG) - defensive behavior and pain modulation

Answer 9

C. The POSTcentral gyrus is associated with the somatotopic location of somatic pain

Question 10

which of these is NOT a major function of the amygdala?

A. Defensive response to viscerosomatic pain
B. Associative learning involving “emotional” stimuli
C. Recognition of “emotional” stimuli
D. Emotional responses
E. Control of sexual behavior

Answer 10

A. While the amygdala receives direct input from ascending spinothalamic and medial lemniscus tracts regarding somatic and visceral pain, defensive response and modulation of pain is primarily associated with PAG function.

Question 11

component of the amygdala that receives the majority of cortical inputs, and the only component that sends axons back to the cortex; it is where associations between emotive and neural stimuli are made

Answer 11

basal and lateral nuclei (basolateral component)

Question 12

component of the amygdala that resembles the striatum and sends axons to structures in the midbrain, pons, and medulla that generate stereotypic responses to unpleasant or threatening stimuli (e.g., freezing, heightened startle reflex, elevated heart rate, etc)

Answer 12

central nuclei (central component)

Question 13

component of the amygdala that is strongly associated with the olfactory system and the medial hypothalamus, and is sexually dimorphic

Answer 13

corticomedial component

Question 14

though major lesions are rarely found in the amygdala, this classic syndrome associated with the amygdala is characterized by psychic blindness, hypersexuality, lack of fear, hyperorality, and memory/learning deficits

Answer 14

Kluver-Bucy syndrome

Question 15

this part of the limbic system that is involved in sadness and effects of anti-depressants; deep brain stimulation of this region has been successful in treating drug-resistant depression.

Answer 15

infralimbic cortex

Question 16

this pair of cortices of the parahippocampal gyrus provide the main input to the hippocampus. what sort of input do they provide?

Answer 16

entorhinal (recognition of objects) and perirhinal (recognition of scenes/landmarks) cortices

Question 17

Complete the input/output pathway of the hippocampus:

Entorhinal cortex (input) –> dentate gyrus –> hippocampus proper –> _____ –> alveus –> fimbria –> fornix –> _____ _____.

Answer 17

subiculum;

mammillary bodies

Question 18

the main source of axons in the fornix is known as the _____

Answer 18

subiculum

Question 19

feedback circuit that is thought to be primarily engaged in the transfer of information from short-term to long-term memory

Answer 19

Papez circuit (medial limbic circuit)

Question 20

people with lesions in the retrosplenial part of the cingulat cortex lose what ability?

Answer 20

ability to navigate

Question 21

damage to the anterior cinguate cortex may result in what loss?

Answer 21

loss of social embarassment

Question 22

The characteristic pathology of this degenerative disease (neurofibrillary tangles, neuritic plaques) begins in neurons in the parahippocampal gyrus and progressively
involves the hippocampus, amygdala, other limbic cortices but rarely, even in end stage, involves primary sensory and motor areas.

Answer 22

Alzheimer’s disease