CNS Development

Question 1

2 major structural divisions of the NS

Answer 1

CNS: brain and spinal cord
PNS: outside the CNS

Question 2

Neurulation

Answer 2

Thickening and folding of the neuroepithelium at the dorsal midline

Question 3

Rhombomeres

Answer 3

Small repetitive segments of the hindbrain

Question 4

Which direction is the
1. Mesencephalic
2. Cervical
3. Pontine
flexure directed?

Answer 4

1. ventrally
2. ventrally
3. dorsally

Question 5

Where are young neurons born?

Answer 5

The ventricular zone

Surrounds the central lumen

Question 6

Mantle zone

Answer 6

The precursor of the gray matter where most mature neurons lie
Where the young neurons migrate to

Question 7

Marginal zone

Answer 7

Axons extending from the mantle layer establish the marginal zone
Its the future white matter

Question 8

The mantle zone of the spinal cord and brain stem is organized into which two plates?
Where do they meet?
What are they connected by 1. dorsally and 2. ventrally?

Answer 8

Ventral (basal) and dorsal (alar) plates
Sulcus limitans
1. roof plate
2. floor plate

Question 9

Neuropore

Answer 9

Part of the neural tube that is open
Since closure starts in the middle, you have an anterior and posterior neuropore
If anterior doesnt close, get ancephaly
If posterior doesnt close, get spina bifida

Question 10

Notochord

Answer 10

Transient axial mesodermal structure involved in the ventral patterning of the NS
Ultimately becomes incorporated in the developing intervertebral disks of the skeleton

Question 11

Prechordal plate

Answer 11

Crucial for the formation and differentiation of the CNS

Question 12

Isthmus

Answer 12

Midbrain-hindbrain boundary

Question 13

Sonic hedgehog

Answer 13

Released from mesoderm and later the notocord
Signals cells to form the basal plate
Secreted in a graded manner in the developing neural tube, concentration is higher ventrally

Question 14

What is released to form the alar plate?

Answer 14

Bone morphogenetic proteins (BMPs)
Wingless/int-related proteins (Wnts)
Secreted in a graded manner in the developing neural tube, concentration is higher dorsally

Question 15

Where are the mitotic cells found in the neural tube?

Answer 15

Where the neural tube meets the lumen

But DNA synthesis occurs furthest away from lumenal surface

Question 16

Neural tube becomes stratified into 3 layers:

Answer 16

1. Ventricular layer (adjacent to neural canal)
2. Mantle layer (contains neuronal cell bodies)
3. Marginal layer (contains nerve fibers)

Question 17

What type of cells are formed from radial migration?

Answer 17

Most excitatory neurons (pyramidal cells)

Question 18

Ganglionic emenents

Answer 18

Migrate far away

Form inhibitory neurons of the cerebral cortex

Question 19

Lateral cerebral fossa

Answer 19

Groove that separates the temperal lobe

In the 4th month

Question 20

Brain ventricles

Answer 20

Lateral in the cerebral hemisphere
Third in the diencephalon
Cerebral aqueduct in the midbrain
Fourth ventricle in the hindbrain

Question 21

What structure produces CSF

Answer 21

Choroid plexus