Lec 11 - Stem cells

Question 1

Define totipotent

Answer 1

Differentiate to any cell type

Question 2

What can neural stem cells (NSC) differentiate to?

Answer 2

neurones or glia cells

Question 3

What is adult neurogenesis

Answer 3

Birth of new adult borne nerve cells

SVZ and SGZ

Question 4

How are neural stem cells (NCS) studied?

Answer 4

Bromodeoxyuridine (BrdU) -
absorbed by dividing stem cells, retained in the nucleus of cells

Double-immunofluoresence histochemistry and confocal microscopy:
co-labeller of BrdU with protein markers of neurones i.e NeuN

Question 5

What is the significance of adult hippocampal neurones? (AHN)

Answer 5

Pattern seperation memory

Ability to distinguish between similar contexts

Question 6

How is neurogenesis regulated?

Answer 6

Decline - age, stress,depression,dementia

Increase - exercise, environmental enrichment

Question 7

Significance of ghrelin relative to AD and dementia

Answer 7

Acts as a hunger suppressant

Calorie restriction results in:
reduced neurodegenerative disease
increased adult hippocampal neurogenesis

Undergoes octanoylation
largest circulating form is des-acyl ghrelin
ghrelin-o-acyl transferase
orexigen - elevated by CR

Ghrelin crosses blood brain-barrier
It enhances long term potentiation (LTP)
-Increase in synaptic strength high stimulation of chemical synapse

Hence:
Mediates hippocampal cell proliferation!

Receptor: GHS-R and expressed in adult dentate gyrus (hippocampus)