3 Limbic System

Question 1

Where is the original limbic lobe?

Answer 1

isthmus- junctional region near the splenium of the corpus callosum between the cingulate and parahippocampal gyro.

Question 2

Does The medial fringe of cortex have granule layers?

Answer 2

No largely agranular–lacks prominent layer II and IV

Question 3

Does the limbic lobe receive direct sensory input from the thalamus?

Answer 3

no

Question 4

Does the limbic lobe receive multimodal sensory from primary and association cortices?

Answer 4

yes

Question 5

What is the limbic lobe reciprocally connected with?

Answer 5

amygdala

Question 6

Do most areas have direct and indirect connections with the hypothalamus?

Answer 6

Yes

Question 7

What is the limbic zone?

Answer 7

ventral striatum nucleus accumbens and ventral caudate are the targets of the limbic lobe

Question 8

Are all areas of the limbic lobe largely weakly connected?

Answer 8

No heavily

Question 9

What provide the main cortical input to the hippocampus?

Answer 9

entorhinal and perirhinal cortices [Part of parahippocampus–both areas receive multimodal sensory inputs]

Question 10

Patients with lesions affecting the posterior parahippocampal gyrus cannot recognize what?

Answer 10

scenes or landmarks [entorrhinal is prominently involved in organizing spatial information]

Question 11

What area of the parahippocampus may be multimodal memory storage?

Answer 11

perirhinal

Question 12

What is the insula covered by?

Answer 12

the opercula

Question 13

Does the insula have granular zones? Types of zones?

Answer 13

Yes- granular, dysgranular, and agranular

Question 14

The granular and dysgranular zones of the insula receive input from where?

Answer 14

VPMpc (taste)
VPLpc/VPI (visceral)
posterior thalamus (pain)

Question 15

What zone in the insula is reciprocally connected with the amygdala?

Answer 15

agranular zone [multimodal zone]

Question 16

What is the sensory cortex of the limbic system?

Answer 16

insula

Question 17

What is a small zone of medial frontal lobe beneath the genu, has prominent projections to the nucleus accumbens, hypothalamus and midbrain?

Answer 17

infralimbic cortex

Question 18

Is the infra limbic cortex visceromotor or viscerosensory?

Answer 18

visceromotor although it does receive visceral related inputs

Question 19

Has the infra limbic cortex shown involvement in sadness and effects of antidepressants?

Answer 19

yes

Question 20

What is a large block of cortex extending from the rostrum to the splenium?

Answer 20

cingulate

Question 21

What cingulate region has its own motor area? what is it a major target for? What role does it largely have?

Answer 21

1. anterior region
2. anterior thalamic nuclei
3. social role

Question 22

Lesions to the anterior cingulate leads to?

Answer 22

loss of social embarassment

Question 23

The more posterior portion of the cingulate is involved in?

Answer 23

self reference

Question 24

What is the key cortical region in representing spatial or context dependent memory?

Answer 24

retrosplenial area of the cingulate cortex

Question 25

Patients eith Lesions to the retrosplenial area cannot do what?

Answer 25

place themselves in environmental context--lose ability to navigate

Question 26

What is a mass of gray matter lying in the temporal lobe deep to the uncut?

Answer 26

the amygdala

Question 27

T-F- the amygdala is a single uniform structure?

Answer 27

False

Question 28

What main components make up the amygdala?

Answer 28

basal and lateral central corticomedial

Question 29

T-F the basal and lateral components of the amygdala are not cortical like?

Answer 29

false they are

Question 30

What component of the amygdala resembles the striatum?

Answer 30

the central part

Question 31

What amygdala components are closely linked and thought to be key structures involved in the learning and expression of emotional behaviors?

Answer 31

basal and central

Question 32

T-F the basal component of the amygdala sends axons to structures involved in the midbrain, pons, and medulla that generate stereotypic responses to unpleasant or threatening stimuli?

Answer 32

False, the central component does this

Question 33

What component of the amygdala resembles the 5 layered entorhinal cortex and parts of the hippocampus?

Answer 33

corticomedial component

Question 34

What amygdala component plays a large role in sexual behavior and is very different from other components?

Answer 34

corticomedial component SEXUALLY DIMORPHIC

Question 35

T-F the corticomedial component of the amygdala receives input from the olfactory system and the lateral hypothalamus?

Answer 35

False--olfactory yes but it is OUTPUT to the MEDIAL hypothalamus

Question 36

Lesions to corticomedial component might lead to what>

Answer 36

problems with sexuality and sexual hallucinations

Question 37

What amygdala component---receives majority of limbic cortical input, sends axons back to cortex, send axons to stratal structures, and is a powerful source of input to basal forebrain cholinergic neurons?

Answer 37

The basal group

Question 38

Where in the amygdala does associations between emotive stimuli and neutral stimuli are made?

Answer 38

basal component

Question 39

Are the axons from the basal component back to the cortex or the one to the striatum for execution of emotive responses?

Answer 39

striatum projections---the ones to the cortex are for recognition

Question 40

patients with basal amygdala lesions may have difficulty with what?

Answer 40

identifying fear in other peoples faces

Question 41

T-F---major lesions like stroke are often found in the amygdala?

Answer 41

False- but subtle changes have been found in many neurodiseases like alzheimers, parkinsons, schizo, depression etc.

Question 42

What classic syndrome--psychic blindness, hypersexuality, lack of fear, hyperorality (increased appetite), memory and learning deficits.

Answer 42

Kluver-Bucy syndrome--amygdala--experimental syndrome in animals

Question 43

How many layers does the hippocampus have?

Answer 43

3

Question 44

Where is the hippocampus located?

Answer 44

edge of the cortical mantle adjacent to the choroid fissure--outersurface lines the lateral ventricle

Question 45

The cell layers of the hippocampus are continuous with what structure?

Answer 45

subiculum at one end and capped by a dense granular dentate gyrus on the other end

Question 46

What is the subiculum continuous with?

Answer 46

entorhinal cortex

Question 47

The cross section of the hippocampus and the dentate gyrus form what?

Answer 47

2 interlocking C's

Question 48

What is the main input to the hippocampus and the dentate gyrus?

Answer 48

entorhinal and perirhinal cortex | [hippocampus send axons back to the subiculum and entorhinal area]

Question 49

T-F the hippocampus sends a small amount of axons to the septum pellucidum base? Return axons?

Answer 49

Ture- septum or septal complex Yes the return axons act as a pace maker

Question 50

What is the main source of fibers in the fornix?

Answer 50

subiculum

Question 51

Where do mammillary bodies send axons to?

Answer 51

anterior thalamic nuclei

Question 52

what is a major role of the hippocampus?

Answer 52

memory- spatial or contextual memory and process object related memory as well

Question 53

Tumors or mild trauma to the medial surface of the anterior temporal lobe result in seizures with what symptoms?

Answer 53

- hallucinations - abnormal olfactory, taste, sexual sensations - stereotypic movements of the tongue and face

Question 54

What does the herpes simplex virus infect in the brain? how?

Answer 54

limbic system--may express limbic specific receptors or anatomical routes from nasal cavity and trigeminal ganglion

Question 55

Where does the characteristic pathology of Alzheimers disease begin? progresses to?

Answer 55

neurons in the parahippocampal gyrus and progressively involves the hippocampus, amygdala, other limbic cortices [rarely effects primary motor/sensory]