L14- Neurogenesis

Question 1

How do neural stem cells differentiate?

Answer 1

Neural stem cell

Lineage restricted progenitor cell

Oligodendrocyte, astrocyte, neuron

Question 2

What is the potency of neural stem cells?

Answer 2

Multipotent- tissue types within neural tissue only

Question 3

What are the NSC markers in vivo?

Answer 3

• Earliest- SOX(2) genes in neural plate

• Late- Nestin (intermediate filament protein)
• RNA- binding protein Musasti
Appear after SOX proteins and persist in adult NSC

Question 4

How are dividing/newborn cells identified?

Answer 4

• BrdU labelling- integrate DNA with BrdU and detect using antibody
• Retroviral labelling- vector only integrates in DNA of divding cells, detected using GFP it is expressed all over cells

Question 5

What regions is adult neurogenesis restricted to?

Answer 5

Subventricular zone of the lateral ventricles

Subgranular zone of the dentate gyrus

Question 6

What are the steps in neurogenesis?

Answer 6

1. Proliferation and fate determination
2. Migration to different locations
3. Differentiation and integration to locations

Question 7

What are the key environmental factors in neurogenesis?

Answer 7

• Endothelial cells
• Astrocytes- key as astroglia found to induce neurogenesis from adult neural stem cells
• Blood vessels

Question 8

How is neurogenesis controlled molecularly?

Answer 8

• Growth factors are needed for proliferation e.g. Wnt
• Transcription factors to trigger differentiation
• Migration- Shh
• Intrinsic and extrinsic factors trigger integration

Question 9

What does Wnt do?

Answer 9

Wnt signalling (secreted by astrocytes) regulates adult neurogenesis
Wnt added to neural stem cells causes them to make more neurons
Blocking Wnt signalling in vivo with lentivirus vector causes 8-fold decrease in neuron production

Question 10

What is the functional relevance of adult hippocampal neurogenesis (AHN)?

Answer 10

• Learning and memory capacity increased and reduced interference between memories by new hippocampal neuronal cells
• Prevent depression and neurodegenerative disorders

Question 11

What are neurodegenerative disorders?

Answer 11

• Alzheimer’s disease
• Parkinsons disease
Cause mood and cognitive decline
Caused by decline in AHN

Question 12

What increases adult neurogenesis?

Answer 12

• Studying
• Running
• Fireworks

Question 13

• What decreases adult neurogenesis?

Answer 13

• Stress
• Sleep deprivation
• High fat diet
• Aging