3300 - Neuro

Question 1

Which layer of the blastopore is NS derive from

Answer 1

Ectoderm

Question 2

What is neurulation

Answer 2

Neural plate folds into neural tube

Question 3

What does the neural tube become

Answer 3

The CNS

Question 4

What is the cephalic flexure between

Answer 4

mesencephalon and rhombencephalon (hindbrain/midbrain)

Question 5

What is the cervical flexure between

Answer 5

rhombencephalon and caudal neural tube

Question 6

What is the pontine/rhombic flexure between

Answer 6

metencephalon and the myelencephalon

Question 7

The prosencephalon (forebrain) becomes the _ and _

Answer 7

Telencephalon and Diencephalon

Question 8

The mesencephalon (midbrain) becomes the

Answer 8

midbrain

Question 9

The rhombencephalon (hindbrain) becomes the _ and _

Answer 9

Metencephalon and myelencephalon

Question 10

What are transcription factors

Answer 10

Proteins that attach to promotor region of a gene to regulate protein expression

Question 11

Regionalisation is due to

Answer 11

different expressions of transcription factors

Question 12

What signals ectoderm to become a) neural tissue (neural induction) b) skin tissue

Answer 12

a) BMP 4 inhibitors
b) BMP 4

Question 13

Where are BMP4 inhibitors released from

Answer 13

“organiser” - dorsal lip of blastopore

Question 14

What is neural induction driven by

Answer 14

morphogen exposure (BMP4 inhibitor)

Question 15

What are morphogens

Answer 15

Signalling factors that direct cell fate from a distance. They create gradients that affect transcription factors

Question 16

What gradient forms after neural induction

Answer 16

ant-post WNT 1 gradient

Question 17

Anterior paraxial mesoderm releases what WNT1 signals

Answer 17

WNT 1 inhibitor signals

Question 18

Where is the isthmic organiser?

Answer 18

At the cephalic flexure between midbrain and hindbrain

Question 19

What does this isthmic organiser release

Answer 19

WNT 1 anteriorly, FGF 8 posteriorly

Question 20

What is the anterior neural ridge and what does it release?

Answer 20

Region in anterior neural plate that acts as secondary organiser - releases WNT 1

Question 21

As hindbrain forms it undergoes further regionalisation into _ which develop into

Answer 21

rhombomeres (1-8) which further develop into pons and medulla

Question 22

What morphogen creates an ant-post gradient along the rhombomeres

Answer 22

retinoic acid (stronger at post end)

Question 23

What transcription factor does retinoic acid stimulate

Answer 23

Krox 20

Question 24

Does Krox 20 differentiate positive or negative numbered rhombomeres

Answer 24

Odds (1, 3, 5, 7)

Question 25

What transcription factor does a lack of retinoic acid stimulate

Answer 25

Hoxb1

Question 26

Does hoxb1 differentiate positive or negative numbered rhombomeres

Answer 26

Even (2, 4, 6, 8)

Question 27

What happens at the border of two rhombomeres to remove intermingling

Answer 27

surface recognition signalling molecules (Ephrin B3 and ephrin A4) repel each other, Hoxb1 and Krox20 respectively.

Question 28

Which morphogens are involved in CNS development (4)

Answer 28

BMP4 inhibitor, WNT-1 (and inhibitor), FGF8 and retinoic acid

Question 29

What transcription factors does WNT 1 gradient effect?

Answer 29

Gbx2 in hindbrain. Otx2 in fore- and mid- brain from WNT1 inhibition. En1/2 in mesencephalon

Question 30

What transcription factors does FGF 8 effect?

Answer 30

FoxG1 in forebrain, En1/2 in metencephalon