Development of Nervous System

Question 1

ectoderm becomes what during neuralation?

Answer 1

neural plate, from it: neural crest: from it: neural groove

Question 2

How many pairs of nerves in CNS?

Answer 2

31 pairs

Question 3

gradient of formation of nervous system?

Answer 3

rostral to caudal

Question 4

closing events of neural fold and problems: explain

Answer 4

separate events, risk of one not closing:

eg. spina bifida and ancephaly

Question 5

what are the 3 distinct vesicles at the rostral end of the neural tube?

Answer 5

prosencephalon (fore)
mesencephalon (mid)
rhombencephalon (hindbrain)

Question 6

prosencephalon splits into?

Answer 6

telencephalon

diencephalon

Question 7

rhombencephalon splits into?

Answer 7

7 segments

Question 8

rhombencephalon splits into two others?

Answer 8

metencephalon: pons
myeloencephalon: medulla

Question 9

where to retinae come from?

Answer 9

optic vesicles of the diencephalon

Question 10

Dicencephalon becomes?

Answer 10

thalamus and hypothalamus

Question 11

What happens to neural crest cells posterior to newly formed neural tube?

Answer 11

migrate away, form lots of structures

Question 12

Neural crest cells become 4 big things:

Answer 12

PNS
melanocytes
muscle, bones of face/jaw
dentine

Question 13

what 4 things does the neural crest form in the PNS?

Answer 13

dorsal root ganglia
symp and parasymp ganglia
enteric ganglia
schwann cells

Question 14

migration of neural crest cells are recovered in what pathological processes?

Answer 14

cancer metastasis

Question 15

how this is the neuroepithelium?

Answer 15

single cell thic

Question 16

what is the ventricular zone?

Answer 16

where neural stem cells start, grow inside-out

Question 17

Stem cells definition?

Answer 17

self-renewing, undifferentiated totipotent: daughter cells able to differentiate

Question 18

what is radial ganglia?

Answer 18

process that guides a migrating neuron

Question 19

What is Reelin mutation?

Answer 19

single protein mutation, malformed cortax

Question 20

what is Lissencephaly? (DCX?)

Answer 20

very few neurons in brain

Question 21

Fragile X causes commonly?

Answer 21

male autism

Question 22

2 devepmental neural disorders?

Answer 22

schizophrenia

fragile X

Question 23

somites do what?

Answer 23

develop muscle and bone

Question 24

neurons controlling distal muscles are medial or lateral?

Answer 24

lateral

Question 25

what does sonic hedgehog do?

Answer 25

induces the floorplate of neural tube to signal ‘anterior’

Question 26

what does the floor plate of the notochord do?

Answer 26

induces ventral horn motor neurons

Question 27

explain induction of interneurons

Answer 27

appear just dorsal to motor neurons in notochord

Question 28

do new neurons have axons?

Answer 28

not really, grows out to meet target

Question 29

how is the initial scaffold of axon tracts laid down?

Answer 29

single pioneering axon

Question 30

How do axons grow?

Answer 30

via growth cone, it tows the axon without moving the soma towards its target

Question 31

How do you steer a growth cone?

Answer 31

membrane bound signals like NGF will promote and inhibit in certain areas

Question 32

What is the critical period? when can it occur?

Answer 32

refinement of synaptic connections that establish functional nervous system, can happen post-natally

Question 33

what happened to kitten with glued eye at birth

Answer 33

after 6 months, it was functionally/permanently blind in that eye due to visual cortex refinement to one eye

Question 34

what did the kitten’s cortex look like who had the deprived eye?

Answer 34

deprived: less representation

open eye: enhanced representation

Question 35

does timing matter for critical period in kitten eye closing?

Answer 35

yes, after critical period over, no permanent changes neurally

Question 36

What is relative activity in relation to critical period?

Answer 36

no blindness if both eyes are covered

depends on relative neural activity

Question 37

How long is a human critical period?

Answer 37

10 years…