3.7 Memory Problems/Neurochemistry, and alzheimer's

Question 1

Where are declarative/explicit memories principally stored?

Answer 1

1. Hippocampus-medial temporal lobe

2. Diencephalon (thalamus, hypothalamus)

Question 2

Where are skills/habit memories stored?

Answer 2

1. Striatum - part of reward circuit
2. Motor cortex
3. Cerebellum

Question 3

Where is the memory for priming stored?

Answer 3

Neocortex

Question 4

Where is the memory for emotional responses stored?

Answer 4

Amygdala

Hippocampus

Question 5

Where is the memory for skeletal musculature stored?

Answer 5

Cerebellum

Hippocampus

Question 6

Where is the memory for non-associative learning stored?

Answer 6

Reflex pathways

Question 7

What are the 5 main neurotransmitters involved in memory?

Answer 7

1. Acetyl choline
2. Glutamate
3. Catecholamines
4. GABA
5. Serotonin

Question 8

What role does serotonin play? What about in deficit?

Answer 8

Sleep
Hunger
Arousal
Mood

Deficit linked to depression; some antidepressants raise serotonin levels.

Question 9

What role does dopamine play? In deficit?

Answer 9

Movement
Emotion
Attention
Learning

Too much - linked to schizophrenia
Too little- linked to tremors, decreased mobility in Parkinsons and ADHD

Question 10

What role does ACh play? In deficit?

Answer 10

Muscle action
Learning & Memory
Attention & Arousal

ACh producing neurons degenerate as alzheimer’s disease progresses
Causes depolarisation of nicotinic ACh ion channels, and second messenger deployment in muscarinic ACh channels

Question 11

What role does noradrenalin play?

Answer 11

Alertness
Arousal

Too little- depressed mood, ADHD-like attention problems

Question 12

What role does GABA play?

Answer 12

Inhibitory neurotransmitter

Too little linked to seizures, tremors, and insomnia

Question 13

What role does glutamate play?

Answer 13

Major excitatory neurotransmitter- main NT in neocortex + pyramidal neurons
Involved in memory

Oversupply can cause migraines or seizures (this why many people avoid MSG in food)
Acts on 3 receptors:
1. NMDA receptor- Na/K/Ca channel - the Ca++ influx = LT potentiation
2. Metabotropic receptor- IP3/other secondary messengers, regulates cellular activity
3. AMPA receptor- Na/K channel

Results in long term post-synaptic potentiation

Glutamine + H2O–> (glutaminase) –> glutamate + NH3

Question 14

What role do the striatal interneurones play?

Answer 14

Motor control

Question 15

What role does the Nucleus basalis of Meynert play?

Answer 15

Attention

Arousal

Question 16

What role does the medial septal nucleus play?

Answer 16

Learning

Memory

Question 17

What role does the brain stem (pedunculopontine) nuclei play?

Answer 17

Relays information to the thalamus

Question 18

What is the role of the PPAR-gamma agonism?

Answer 18

Agonists of the PPAR-gamma reduce or prevent neuroinflammation
Modulate mitochondrial function

May improve mitochondrial function in alzheimer’s disease

Question 19

What is the role of phosphodiesterases?

Answer 19

PDE-9 hydrolises cGMP- reducing long term potentiation

May improve function in Alzheimer’s disease

Question 20

Aggregates of amyloid plaques and phosphorylated tau protein are found in which disease?

Answer 20

Alzheimer’s disease

Question 21

What is the role of Apolipoprotein E? How is it implicated in alzheimer’s disease?

Answer 21

ApoE has a role in cholesterol metabolism, membrane stability and repair

The E4 variant is the largest known genetic risk factor for late-onset sporadic Alzheimer’s disease (AD)

Question 22

Name 3 acetylcholinesterase inhibitors

Answer 22

1. Donepezil
2. Galantamine
3. Rivastigmine