Development of Multicellular Organisms II

Question 1

Describe phase 1 of neural development

Answer 1

different cell types (neurons, glial cells) develop independently at widely separate locations in embryo according to local program and are unconnected

Question 2

Describe phase 2 of neural development

Answer 2

Axons and dendrites grow out along specific routes setting up a provisional but orderly network of connections between various parts of the nervous system

Question 3

Describe phase 3 of neural development

Answer 3

continues into adult life, connections are adjusted and refined through interactions with distant regions via electric signals

Question 4

Neurons are produced in association with ____ cells

Answer 4

glial

Question 5

Where do neurons and glial cells develop from?

Answer 5

ectoderm

Question 6

Where is the CNS derived from? the PNS?

Answer 6

CNS: neural tube
PNS: neural crest

Question 7

What controls differentiation into neurons (lateral inhibition and positive feedback)?

Answer 7

delta notch

Question 8

The neural crest originate at the ______ end of the neural tube

Answer 8

dorsal

Question 9

Fate of the neural crest cells depend on what?

Answer 9

where they migrate to and settle

Question 10

What does a typical immature neuron have?

Answer 10

cell body, long axon, several short dendrites

Question 11

Growth cone behavior is dictated by its ______ machinery

Answer 11

cytoskeleton

Question 12

Growth cones grow out of ______ and _____

Answer 12

filopodia and lamelopodia

Question 13

Monomeric GTPases Rho and Rac control the assembly/disassembly of _______ which control movement of growth cone

Answer 13

actin filaments

Question 14

What are chemotactor factors released by?

Answer 14

neighboring cells

Question 15

What are the two important classes of hemophiliac cell adhesion molecules?

Answer 15

immunoglobin superfamily

cadherin family

Question 16

Ventral clusters of spinal cord neurons develop as ____ neurons send out long axons to connect with specific subset of muscles

Answer 16

motor

Question 17

Intermediate location has ______ that connect specific set of nerve cells to each other

Answer 17

inter neurons

Question 18

Describe chemotactic factors

Answer 18

secreted by cells, act as guidance factors at strategic points along path. May be attractive and repulsive

Question 19

What does the first stage depend on?

Answer 19

nectarine secretion

Question 20

Binding of netrin to its receptor causes opening of ______ channels

Answer 20

TRPC (transient receptor potential C)

Question 21

What does Slit do?

Answer 21

repels growth cones and blocks entry to the midline

Question 22

Target produces limited amount of specific _______ factors needed for survival

Answer 22

neurotrophic

Question 23

What was the first prototypical neurotrophic factor?

Answer 23

nerve growth factor (NGF)

Question 24

What family does NGF belong to? what is the receptor?

Answer 24

family: neurotrophins
receptor: tyrosine kinase (TrkA)

Question 25

What does NGF do?

Answer 25

promotes survival of specific sensory neurons and sympathetic neurons

Question 26

What is the short term effect of NGF?

Answer 26

effect on growth cone and neurite extension. Effect is local, direct, rapid and independent of communication with cell body

Question 27

What is the long term effect of NGF?

Answer 27

effect on cell survival. Mediated by its receptor, uptake into cells via endocytosis and stimulation of downstream signaling pathways

Question 28

What two rules are synaptic remodeling dependent on that rate spatial order?

Answer 28

• axons from cell in different regions of retina compete for tectal neurons
• axons from neighboring sites which are excited at same time cooperate/collaborate to retrain and strengthen synapses with tectal neuron

Question 29

neurons that fire together _____ together

Answer 29

wire

Question 30

entry of ____ through the glutamate receptor ( _____ receptor) triggers lasting change in synaptic strength

Answer 30

calcium, NMDA