Final Exam (Last Lecture)

Question 1

Where is the limbic system found?

Answer 1

Rim of cortex surrounding the corpus callosum and diencephalon

Question 2

What is the limbic system composed of?

Answer 2

The limbic cortex and related subcortical nuclei

Question 3

What are the two ‘subsystems’ of the limbic system?

Answer 3

Hippocampus and amygdala

Question 4

What are the components of the limbic system?

Answer 4

Hippocampus, parahippocampal gyrus (entorhinal cortex), cingulate gyrus, septal region, and amygdala

Question 5

What is the parahippocampal gyrus?

Answer 5

Major junctional region between the cerebral neocortex and allocortex of the hippocampal formation

Question 6

What is the entorhinal cortex?

Answer 6

Brodmann Area 28

The anterior portion of the parahippocampal gyrus

Question 7

What does ‘neocortical’ mean?

Answer 7

Afferent and efferent connections with association cortex areas

Question 8

What does ‘allocortical’ mean?

Answer 8

Afferent and efferent connections with the hippocampal complex

Question 9

What are the three regions of the hippocampal complex?

Answer 9

Subiculum, hippocampus proper, and dentate gyrus

Question 10

What is the principle cell of the dentate gyrus?

Answer 10

Granule cells

Question 11

What is another name for the hippocampus proper?

Answer 11

Cornu ammonis

Question 12

How many subdivisions are there of the hippocampus proper?

Answer 12

4 subdivisions (CA1-4)

Question 13

What is the principle cell of the hippocampus proper?

Answer 13

Pyramidal

Question 14

What are the parts of the hippocampal cortex?

Answer 14

Subiculum and entorhinal cortex

Question 15

What is the principle cell of the hippocampal cortex?

Answer 15

Pyramidal

Question 16

Where do hippocampal afferents from the association cortex go?

Answer 16

Unimodal and multimodal association cortices -> Entorhinal cortex and subiculum -> Dentate gyrus

Question 17

Where do afferents from the amygdala go?

Answer 17

Hippocampus proper/subiculum

Question 18

Which hippocampal regions modulates emotion of memory?

Answer 18

Hippocampus proper/subiculum

Question 19

Where are the modulatory inputs to the hippocampus from? Which neurotransmitters do they utilize?

Answer 19

Septal nuclei (ACh) -> fornix

Locus coeruleus (NE)
Raphe nuclei (5-HT)
VTA (DA)

Question 20

Where do the hippocampal efferents from the subiculum go?

Answer 20

Subiculum -> Entorhinal cortex -> Association cortex

Subiculum -> Fimbria/fornix -> Septal nuclei, ventral striatum, thalamus, mammillary body

Question 21

What is the role of the mammillary body in memory?

Answer 21

Autonomic component of emotional memories

Question 22

What are the functions of the hippocampus?

Answer 22

Declarative long-term memory formation

• Long-term potentiation
• More calcium = stronger potentiation

Spatial memory and navigation
- Place cells

Question 23

What diseases are associated with hippocampal damage?

Answer 23

Aging (senile dementia), Alzheimer’s disease, and Temporal lobe epilepsy (treatment could be removing hippocampus)

Question 24

What was done to Patient HM? What was the result?

Answer 24

Bilateral medial temporal lobectomy for intractable epilepsy

Severe anterograde amnesia (inability to form new episodic memories)

Question 25

What is the amygdala? Where is it located?

Answer 25

Collection of about a dozen nuclei lying beneath the limbic lobe Anterior end of hippocampus and inferior horn of lateral ventricle

Question 26

How is the amygdala divided?

Answer 26

Medial, central, and basolateral nuclear divisions

Question 27

What is the function of the amygdala?

Answer 27

Emotional responses, primarily ones associated with fear Roles in food seeking and sexual behaviours

Question 28

What are the three types of sensory info carried by amygdala afferents?

Answer 28

1. Sights, sounds, touch, smell, and taste 2. General sense of physical/emotional comfort/discomfort 3. Visceral sensory inputs (i.e., cardiac)

Question 29

Where do the basolateral complex afferents of the amygdala come from? What type of afferents are they?

Answer 29

LGN (visual), MGN (auditory), and VPN/VPL (somatosensation) Subcortical

Question 30

Where do the afferents of the amygdala central nucleus come from? What type of afferents are they?

Answer 30

Visceral sensory inputs, hypothalamus, brainstem nuclei | Subcortical

Question 31

Where do cortical inputs to the amygdala arrive?

Answer 31

Cortical inputs arrive at the basolateral complex before being distributed to other regions

Question 32

Which unimodal sensory association areas project to the amygdala?

Answer 32

V4: object/face recognition V5: motion detection

Question 33

Which association cortices project to the amygdala?

Answer 33

Orbital cortex Anterior cingulate cortex Insula

Question 34

Where do amygdala efferents go to? Which function are these corresponding to?

Answer 34

PAG to medulla/raphespinal tract - Antinociception PAG to medullary reticulospinal tract - Freezing (defense reaction) Locus coeruleus - Arousal/attention NE medullary neurons to lateral grey horn - Tachycardia/hypertension Hypothalamus/dorsal nucleus of vagus to heart - Bradycardia/fainting (due to strong emotion) Hypothalamus - release corticotropin releasing hormone (stress) Parabrachial (dorsal pontine) nucleus to medullary respiratory nuclei - Hyperventilation

Question 35

Which functions are regulated by the amygdala?

Answer 35

Linking perception of objects and situations with appropriate emotional responses (esp. in danger) Emotional aspects of learning (those associated with strong emotions are more likely to be remembered) Phobias/anxiety

Question 36

What is the result of bilateral amygdala damage?

Answer 36

Decreased aggression | Impaired ability to learn or remember the appropriate emotional and autonomic responses to stimuli

Question 37

What is bilateral temporal lobe damage?

Answer 37

Removal of temporal lobes back to the level of the primary auditory cortex Loss of amygdala, most of hippocampus, and parahippocampal gyrus

Question 38

Which disorder is associated with bilateral temporal lobe damage? What are the effects?

Answer 38

Klüver-Bucy syndrome Fearless and placid, absence of emotional reactions Hypersexuality High degree of attention to sensory stimuli