Early Development of NS Lec 2

Question 1

Gastrulation

Answer 1

Day 18
Ectoderm, Mesoderm, endoderm
defines
-midline
-anterior/posterior
-dorsal/ventral

Question 2

Neural induction

Answer 2

BMPs- push ectoderm towards epidermal state

Question 3

Inhibitors of BMP

Answer 3

Produced by notochord

• Chordin
• Noggin
• Fillistatin

Question 4

Blocking BMP

Answer 4

Default

induces cells to take on neural fate

Question 5

BMP signaling

Answer 5

BMP binds serine kinases and SMAD complex
SMAD to nucleus- mediates transcription
SHH dependent

Question 6

FMF signaling

Answer 6

Critical for neural induction prior to BMP inhibition

Question 7

Neurulation

Answer 7

Day 18-24
Neural tube formed after induction
Stem cells make up tube

Question 8

Whats important for neural tube closer

Answer 8

Folic acid and B-Complex vits

Question 9

Cranial Neural crest

Answer 9

Cranial ganglia
bones
Cartilage in face and head

Question 10

Trunk neural crest

Answer 10

DRG
sympathetic ganglia
adrenal medulla
melanocytes

Question 11

Vagal and sacral neural crest

Answer 11

parasympathetic ganglia

Question 12

Cardiac neural crest

Answer 12

cartilage
melanocytes
neurons of the pharyngeal arches
regions of the heart

Question 13

Ventral signal

Answer 13

motor
Floor plate
SHH

Question 14

Dorsal signal

Answer 14

sensory
roof plate
mainly BMP

Question 15

SHH signaling

Answer 15

SHH
PTC
SMO
GLi
Transcription
-ventral (motor neuron) fate

Question 16

Developmental defects without SHH

Answer 16

Holoprosencephaly

Cyclopia

Question 17

Anterior/posterior patterning

Answer 17

overlaps neural induction, which overlaps gastrulation

• spinal cord
• Rhombencephalon
• Mesencephalon
• Proencephalon

Question 18

Rhombencephalon

Answer 18

Methencephalon-pons

myelencephalon-medulla

Question 19

mesencephalon

Answer 19

midbrain

Question 20

proencephalon

Answer 20

diencephalon- thalamus and retina

telencephalon- forebrain

Question 21

HOX genes

Answer 21

Posterior CNS
involved in differences in 
-spinal cord
-medulla
-pons
NO brain HOX

Question 22

Ventricular zone

Answer 22

cells surround CSF

NSC and neural progenitor cells divide and differentiate here

Question 23

Neural stem cells

Answer 23

Unlimited renewal

give rise to all cells in CNS

Question 24

Progenitor cells

Answer 24

Derived from neural stem cells
Neurons OR glia
Not unlimited renewal

Question 25

Neurogenesis time line

Answer 25

Neurons- by 2nd trimester
Gliogenesis- after birth until 20yo
almost no myelination at birth

Question 26

Early development

Answer 26

NSCs divide symmetrically

-increase size of ventricular zone and brain

Question 27

Later development

Answer 27

NSCs divide asymmetrically

-1 NSC and 1 Progenitor

Question 28

Late development

Answer 28

NSCs divide symmetrically

-give rise to 2 progenitor

Question 29

Regulating neural cell differentiation

Answer 29

Notch and bHLH

Requires cell to cell contact

Question 30

Notch

Answer 30

Through delta- intracellular notch cleaved
goes to nucleus
activates bHLH genes
positive feedback loop
-bHLH upregs delta
bHLH primed to differentiate into neuron

Question 31

Notch hyperactivated

Answer 31

in surrounding cells to shut off bHLH and keeps cells pluripotent

Question 32

Radial migration

Answer 32

Inside out manner

Cells closest to VZ form first

Question 33

Radial glia

Answer 33

extends from VZ to pail surface

• neuroblast migrate along until they reach pail
• give rise to neurons and provide scaffolding

Question 34

Primary neurulation

Answer 34

Complete with first 3 weeks
-after which neural precursor and neural development begins

brain extremely sensitive to nutrition and environmental toxins

Smaller brain
decreased amount of gray matter in cortex and caudate