L12 - Gradients

Question 1

Netrin diffusion distance

Answer 1

0.5mm

Question 2

Netrin

Answer 2

secreted guidance laminin like protein

Question 3

Commissural axons turn after midline crossing due to

Answer 3

attractant or repellant gradient

Question 4

Large/small AP explants

Answer 4

determines whether AP gradient made by diffusible or non-diffusible cue

Question 5

AP gradient made by

Answer 5

long range diffusible attractant

Question 6

WNT4 expression

Answer 6

Anterior to posterior gradient

Question 7

Wnt4 expression distance

Answer 7

several millimeters - 7mm

Question 8

Gradient measurement

Answer 8

spatial or temporal detection

Question 9

Factors influencing accurate orientation to source

Answer 9

absolute concentration - chemoattractant

gradient steepness

Question 10

Mechanisms to enhance gradient detection range

Answer 10

amplification

adaptation

Question 11

Amplification

Answer 11

local enhancement of signal
inhibition of signal reception
receptor clustering

Question 12

Chemoattractants activate

Answer 12

PI3Kinase via GPCR

Question 13

PH domains

Answer 13

localised to filopodia closest to source

Question 14

Symmetric vesicle transport

Answer 14

occurs in GCs in response to cues

Question 15

Gradient sensitivity

Answer 15

signal amplification

Question 16

Growth cone adaptation

Answer 16

cycles of sensitisation and desensitisation

Question 17

Gradient distance depends on

Answer 17

diffusible or non-diffusible molecules

Question 18

Longest gradient

Answer 18

linear substrate bound molecule