Lecture 8- The limbic system

Question 1

Deep nuclei is formed:

Answer 1

Around ventricles

Question 2

Deep nuclei in the limbic system are present:

Answer 2

Around the inside of ventricles (amygdala, hippocampus, fornix, mammillary bodies)

Question 3

Deep nuclei in the basal nuclei are present:

Answer 3

Around the outside of ventricles (caudate, lentiform nuclei)

Question 4

Importance of amygdala in the limbic system:

Answer 4

Connections to hippocampus
Output to hypothalamus

Question 5

Importance of fornix in the limbic system:

Answer 5

Connects hippocampus to mammillary bodies

Question 6

Importance of hippocampus in the limbic system

Answer 6

Connections with amygdala
Output to hypothalamus via white matter tracts (fimbria and fornix)

Question 7

Hippocampal location:

Answer 7

In the medial temporal lobe

Question 8

3 primary cell layers in hippocampus

Answer 8

Dentate gyrus, CA3 and CA1

Question 9

Major output of hippocampus:

Answer 9

Via the fimbria and fornix

Question 10

Primary role of hippocampus:

Answer 10

Encode and consolidate memories

Question 11

Amygdala receives ____ input from the environment and it causes ____

Answer 11

Visual and auditory, threat detection

Question 12

Fight or flight response in amygdala is invoked by which areas:

Answer 12

Hypothalamus and brainstem

Question 13

Damage of the amygdala leads to several impairments:

Answer 13

• Inability to recognize fearful situations or fear
• Loss of inhibition
• Impaired emotional memories

Question 14

Abnormal activation of the amygdala is associated with:

Answer 14

• Panic disorder
• PTSD
• GAD

Question 15

• Structures involved in memory formation

Answer 15

Thalamic nuclei, fornix, amygdala, mammillary bodies, hippocampus, cingulate cortex, anterior thalamic nuclei

Question 16

Hippocampus role in memory formation

Answer 16

• Who what when why

Question 17

Mammillary body’s role in memory formation

Answer 17

Relay to thalamus

Question 18

Anterior thalamic nuclei role in memory formation

Answer 18

Alertness, relay to cortex

Question 19

Cingulate cortex role in memory formation

Answer 19

Cortical connections, reality check

Question 20

Amnesia:

Answer 20

Memory loss of facts or experiences

Question 21

H.M.

Answer 21

Underwent bilateral medial temporal lobe excision for uncontrollable seziures
- Surgery cured seizures, caused anterograde amnesia
- No effect on intellectual function
- No retrograde amnesia

Question 22

Anterograde amnesia:

Answer 22

A deficit in the ability to form new memories following the time of brain injury

Question 23

Retrograde amnesia:

Answer 23

A loss of long-term memories

Question 24

Why can anterograde and retrograde amnesia occur independently?

Answer 24

Multiple memory systems utilize different brain regions

Question 25

Short term memory function and location:

Answer 25

Function: Acquisition and short-term storage of declarative, episodic (events) or semantic (facts), memories
Location: Medial temporal lobe (thalamus, amygdala, hippocampus)

Question 26

Long-term memory function and location:

Answer 26

Function: Long-term storage of declarative (episodic and semantic) memories
Location: Neocortex (somatosensory, visual, etc. cortex)

Question 27

Hippocampal atrophy results in:

Answer 27

Inability to store new memories of events after injury (anterograde amnesia)
Inability to consolidate events
Largely retain ability to recall past events
LOSS OF DENDRITES

Question 28

Alzheimer’s disease pathology:

Answer 28

Neurofibrillary plaques and tangles

Question 29

Procedural (motor) memory function and location:

Answer 29

Acquisition and long-term retention of nondeclarative memory
Location: cerebellum and basal ganglia

Question 30

The hippocampus is the only adult human CNS site that undergoes ____

Answer 30

Adult neurogenesis
- New neurons only become GABAergic (inhibitory) neurons