lecture 12- neurotrophins and apoptosis

Question 1

state the 2 points of the neurotrophic factor hypothesis

Answer 1

neurones are produced in excess of need and the excess is eliminated over time

neurotrophic factors emanate from targets to promote survival according to tissue size

Question 2

what is the proof for the neurotrophic factor hypothesis

Answer 2

in limb bud experiments, extra targets lead to more neurons and less targets lead to less neurons

Question 3

what does the number of cells surviving correlate with

Answer 3

the size of the tissue innervated

Question 4

what are the 2 classes of apoptosis genes

Answer 4

anti apoptotic- prevent cell death
pro apoptotic- required for cell death

Question 5

what are the 2 classes of caspases

Answer 5

initiator
executioner

Question 6

what is nerve growth factor

Answer 6

a neurotrophic factor that prevents apoptosis in neurons so they can form circuits

Question 7

what does trophic mean

Answer 7

supports survival and growth

Question 8

what does tropic mean

Answer 8

directs the movement

Question 9

is NGF tropic or trophic

Answer 9

both

Question 10

what is special about Pro NGF and what does this mean

Answer 10

it actually induces apoptosis so different states of the same protein have opposite effects

Question 11

describe NGF signalling

Answer 11

use TRKs
singnalling endosome formed

Question 12

what does the MAP pathway regulate

Answer 12

transcription

Question 13

what does the Akt pathway regulate

Answer 13

apoptosis

Question 14

what is cell death also useful for, apart from size control

Answer 14

removing transient structures ie. subplate neurons