week 12- AD

Question 1

When was AD first described?

Answer 1

1906 by Alois Alzheimer

Question 2

What is AD defined by?

Answer 2

Abnormal degenerative processed seen post-mortem

• Atrophy of the whole brain
• Shrinkage of hippocampal areasm cortex and enlarged ventricles in late AD.
• Presence of neutritic plaques (extracellular)
• Neurofibrillary tangles (intracellular)

Question 3

How do plaques and tangles lead to nerve cell death?

Answer 3

They damage nerve cells causing their dysfunction and eventually leads to their death.

Question 4

Where does degeneration begin?

Answer 4

At the nuclues basalis

At this time there is vague and undiagnosed memory symptoms.

Question 5

Where does degeneration spread to at time of early diagnosis?

Answer 5

Closer projection areas such as the hippocampus, amygdala and entorhinal cortex

Question 6

Where does degeneration spread at time of nursing home placement?

Answer 6

Throughout the neocortex, eventually involving neurons and neurotransmitters.

Question 7

What happens at mild AD stage?

Answer 7

• Person can function independently
• May still drive/work/socialise
• May have memory lapses
• Friends and family begin to notice difficulties

Question 8

What happens at moderate AD stage?

Answer 8

• Dementia symptoms more pronounced
• May have greater difficulty performing tasks, such as paying bills, but may still remember significant details about their life.
• Typically, longest stage

Question 9

What happens at severe AD?

Answer 9

• Symptoms are severe
• Lose ability to respond to environment, carry conversation and eventually to control movement.
• Memory and cognitive skills continue to worsen
• Significant personality changes may take place.
• Individuals need extensive help with daily activities

Question 10

What neuro transmitter is in the cholinergic system?

Answer 10

Acetylcholine

Question 11

What precursors form ACh?

Answer 11

Choline - synthesized from the diet and intraneuronal sources
Acetyl Coenzyme - made from glucose in the neuronal mitochondria.

Question 12

What does ACh act on?

Answer 12

Muscarinic and nicotinic cholinergic receptors

Question 13

What is Acetylchoninesterase (AChE)?

Answer 13

The enzyme that breaks up acetylcholine into choline and acetate.

Question 14

What other enzyme can break up ACh?

Answer 14

Butylcholinesterase (BuChE)

Question 15

What does the cholinergic system use ACh for?

Answer 15

To regulate memory, arousal, concentration, attention and consciousness (Sadock, Sadock & Ruiz, 2009)

Question 16

What areas of the brain does ACh project to from the brain stem and basal forebrain?

Answer 16

Prefrontal cortex, thalamus, hypothalamus, amygdala and hippocampus (Stahl, 2008)

Question 17

Neurons in where are responsible for regulating motor movements?

Answer 17

Striatum

Question 18

Where is the Nucleus basalis of Meynert located?

Answer 18

In the basal forebrain

Question 19

What is the Nucleus basalis of Meynert?

Answer 19

• Principal site of cholinergic cell bodies for axons that project to the hippocampus and amygdala and throughout the neocortex.
• These neurons thought to mediate memory and higher cortical functions such as learning, problem solving and judgement.
• These neurons degenerate early and progressively throughout the course of AD.

Question 20

What are learning and memory blocked by?

Answer 20

Drugs that can impair the synthesis and release of acetylcholine

• In humans, scopolamine administration impairs long-term memory (particularly declarative)

Question 21

How much loss is associated with AD?

Answer 21

90% in the brain’s production of the neurotransmitter acetylcholine in the basal forebrain and hippocampus

Question 22

What is the cholinergic hypothesis?

Answer 22

• Cholinergic system responsible for AD.

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