l7

Question 1

why is balance of stem cells, differentiated cells and TAP cells needed?

Answer 1

• need to have enough to proliferate to replace damaged/dieing cells
• overproliferaiton / too many cells can lead to cancers

Question 2

how is the balance of TAP, stem cells and differentiated cells achieved?

Answer 2

by feedback loops

e.g. if there is lots of a cell - stop dividing

Question 3

what genes does Shh signalling (GliA) activate?

Answer 3

-Myc, Cyclin D1, Bcl-2
-these are cell cycle genes which control cell survuval, proliferation and renewal
(TAP cell properties)
(why too much shh - cancer)

Question 4

what does the bcl-2 gene do?

Answer 4

prevent apoptosis

Question 5

How do we think Shh governs TAP cell populations?

Answer 5

-it is likely Shh interacts/integrates with other signalling pathways in order to govern a TAP population

Question 6

what are the actions of Shh in the telencaphalon?

Answer 6

• Shh has 3 roles
  1) patterning
  2) progenitor expansion
  3) Nkx2.1 maintenance

Question 7

what are the thought actions of Shh in hypothalamic development?

Answer 7

Shh has 4 roles

1) induce a pre-hypthalamic cell
2) select an anterior progenitor cell
3) amplify anterior progenitor population (TAP) (upregulate cell cycle genes)
4) Has some function in anterior progenitor differentiaion (e.g. upregulate Rx2)

Question 8

What do Shhs functions in hypothalamic development show?

Answer 8

Shows a single signal (Shh) may be acting on the same cell line overtime - may have different effects on different generations to produce the hypthalamus

Question 9

what are the 2 known places in the adult brain where we know neurogenesis can occur(2010)?

Answer 9

• subventricular zone (lateral ventricle)

- subgranular zone (dendate gyrus of hippocampus - memory)

Question 10

what do radial glia give rise to first?

Answer 10

radial glia first give rise to nearal cells then glia.

neurons made before astrocytes/glia

Question 11

what does the hypothalamus control?

Answer 11

• CORE BODY HOMEOSTASIS/FUNCTIONS
• BP, hunger, temperature, stress, water balance
• reproduction (dopinergic neurons)

Question 12

give something the posterior hypothalamus control?

Answer 12

-controls shivering

Question 13

where are hypothalamic tanycytes found and what are they?

Answer 13

• radial glia like cells (are they stem cells??)
• found in mouse medial hypothalamus - base of 3rd ventricle (ventral half of medial hyp)
• are they in a niche with blood vessels?