brain development

Question 1

from which germ layer does the nervous system develop?

Answer 1

the ectoderm

Question 2

what is the 3-vesicle stage?

Answer 2

3 brain vesicles are at this stage present > forebrain, midbrain and hindbrain

Question 3

what is the 5-vesicle stage?

Answer 3

2 additional vesicles form, one in the forebrain and the other in the hindbrain. this is at a later stage than the 3-vesicle stage

Question 4

what are the major 3 stages of brain cell development?

Answer 4

1. cell proliferation
2. cell migration
3. cell differentiation

Question 5

what are the 5 positions of cell proliferation

Answer 5

1. cell extends a process
2. cell’s DNA is copied
3. two complete copies of DNA
4. cell retracts arm from pia surface
5. cell divides in 2

Question 6

on what depends the fate of daughter cells on the plane of cleavage during division?

Answer 6

1. symmetrical division > both daughter cells remain in the ventricular zone to divide aging
2. asymmetrical division > daughter cells farthest away from the ventricle ceases division and migrates away.

Question 7

what kind of division is there for radial glial cells?

Answer 7

symmetrical > produces 2 progenitor cells to expand population of proliferative cells
early asymmetrical division > promotes increase neuron population
later asymmetrical division > promotes glial production

Question 8

how does the cortex develop?

Answer 8

1. first cell migrate to cortical plate, these form the subplate
2. they differentiate into neurons, and become layer 4. they migrate en collext in cortical plate
3. process repeated again untill all layer differentiated
4. subplate neurons disappear.

Question 9

What are the types of cell differentiation?

Answer 9

1. neuronal differentiation
2. astrocyte differentiation
3. oligodendrocyte differentiation

Question 10

what regulates the fate of cell in the developing cerebral cortex

Answer 10

notch signalling > a cell surface receptors that interacts with a ligand.

Question 11

what is gliogenesis

Answer 11

generation of glial cells

Question 12

What happens to a glial progenitor if a notch signal promotes?

Answer 12

differentiates into astrocytes

Question 13

what happens to a neuronal progenitor if a notch signal inhibits?

Answer 13

differentiate into neurons

Question 14

what is the neurotrophic factors hypothesis?

Answer 14

This hypothesis states that developing neurons compete with each other for a limited supply of a neurotrophic factor (NTF) provided by the target tissue.

Question 15

how is a synapse formed from a growth cone

Answer 15

1.dendritic filopodium contacts an axon
2. contact leads to the recruitment of synaptic vesicles and active zone proteins to the presynaptic membrane
3. neurotransmitter receptors accumulate post-synaptically

Question 16

what is synaptic plasticity?

Answer 16

synapses strengthen or weaken over time, linked to LTP course 1004

Question 17

What is the right order of experience-dependent synapse formation?

Answer 17

1. seeing/hearing
2. receptive language/speech production
3. higher cognitive functions

Question 18

How does the peripheral nerves heal from an injury?

Answer 18

severed axons can regrow past the site of injury, cells of schwann can promote the growth of it

Question 19

How does the central nerves heal from an injury?

Answer 19

Severed axons typically fail to regrow past the site of injury, there are no schwann cells that promote growth, thus you get glial and astrocyte scarring

Question 20

what is a neurite?

Answer 20

beginning part of a growth cone

Question 21

what does the mesoderm give rise to?

Answer 21

muscles and vascular system

Question 22

what does the endoderm give rise to?

Answer 22

gut tube, lungs, liver and pancreas

Question 23

What is the BMP signal?

Answer 23

important signalling molecule, prevents cells from differentiating into default neural cells

Question 24

what are nodes of ranvier?

Answer 24

microscopic gaps found in myelinated axons