Cholinergic Basal Forebrain and Alzheimer's Disease

Question 1

Where are the 3 major Cholinergic regions of the brain? (M.B.S)

Answer 1

• Basal Forebrain
• Mesopontine tegmentum
• Striatum

Question 2

What are the four subnuclei of the Basal Forebrain?

Answer 2

Ch1 - Medial Septum
Ch2 - Vertical-diagonal band of Broca
Ch3 - Horizontal-diagonal band of Broca
Ch4 - substantia innominata/nucleus basalis of Meynert

Question 3

What is a consequence of loss of cholinergic neurons in the BF?

Answer 3

• impaired higher-order cognitive processes (executive functions, spatial memory, learning, memory)

Question 4

what is the function of cholinergic neurons in the BF?

Answer 4

• mediates inhibitory and excitatory neurotransmission

Question 5

What are the two Acetylcholine receptors in the BF?

Answer 5

Gq - excitatory

Gi/o - inhibitory

Question 6

What is Alzheimer’s disease, and related symptoms and causes?

Answer 6

• most common cause of dementia
• loss of intellectual and social abilities
• tissue degeneration

Question 7

What are the cognitive symptoms of AD?

Answer 7

• impaired memory, language, visuo-spatial, attention, executive functions

Question 8

What can be seen histologically in AD patients?

Answer 8

• presence of Amyloid Plaques
• Tau tangles
• neuro/synaptic degeneration

Question 9

What are two hypotheses on the causes of AD?

Answer 9

• amyloid Cascade hypothesis
  (amyloid -> Tau -> atrophy -> cognitive decline -> AD)
• Cholinergic hypothesis
  (cholinergic dysfunction is the cause AND consequence of AD, loss of cholinergic activity -> cognitive deterioration)

Question 10

what are ways to detect AD in patients?

Answer 10

PET

• inject tracer which sticks to amyloid
• observe how long tracer lasts, compared to control subject

MRI

• blue marker indicates cortical atrophy
• red marker indicates BF atrophy

Question 11

What tasks can be tested for AD patients?

Answer 11

navigation tasks