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Question 1

What are laminae and nuclei in the brain?

Answer 1

Laminae are layers of cells like the cerebral cortex and nuclei are groups of neurons that are clustered together, share common functions, connectivity, and often neurotransmitters.

Question 2

What are glia.

Answer 2

Braincells other than neurons.

Question 3

How is the anterior-posterior neural tube patterned?

Answer 3

It’s polarized along the neuraxis. The neuraxis is patterned by transcription factors, with Otx2 in the fore and midbrain and Gbx2 in the hindbrain. Later factors specify different cortical regions

Question 4

What primary vesicles are there and what secondary vesicles do they form?

Answer 4

Prosencephalon -> telencephalon and diencephalon
Mesencephalon -> mesencephalon
Rhombencephalon -> metencephelon and myelencephalon

Question 5

What does the brain stem consist of?

Answer 5

The midbrain, Pons, and medulla, so the mesencephalon, parts of the metencephalon, and the myelencephalon.

Question 6

What is the isthmus?

Answer 6

The boundary between the midbrain and the hindbrain, it acts as a local organizer.

Question 7

What are rhombomeres? What do they do?

Answer 7

Segments in the rhombencephalon (hindbrain). They each give rise to a different structure and function in the mature brain.

Question 8

Do Hox genes play a part in hindbrain segmentation and patterning?

Answer 8

Yes.

Question 9

Describe the growth and differentiation of the layers and zones of the neuroepithelium.

Answer 9

The germinal neuroepithelium has neural stem cells and gives rise to neurons and glial cells. In the ventricular zone (lumen/ventricle side), stem cells keep dividing. Some cells migrate into the intermediate zone (mantle or gray matter) where they differentiate. Lastly, a marginal zone (white matter) is composed of axons sheathed in lipid rich myelin (pial surface).
This development occurs inside-out

Question 10

What is the birthday of a neuron?

Answer 10

The final mitotic division of a neural stem cell.

Question 11

What determines if a stem cell or fated neuron/glial cell is produced?

Answer 11

The plane of division of the stem cell.

Question 12

What happens to newly born neurons?

Answer 12

They migrate radially to the pial surface along radial glia into the cortical plate. Earlier born neurons migrate shorter, later born migrate farther. This explains the inside out development of the nervous system.

Question 13

What are radial glia cells?

Answer 13

Slightly differentiated neural stem cells, all neurons and glial cells develop from these. They are able to self-renew and act as a scaffold for newborn cells to migrate radially towards the pial surface.

Question 14

Does the position of a radial glia cell change over its life cycle?

Answer 14

No. The position of the nucleus in its cell does, however, this is called interkinetic nuclear migration and occurs during the cell cycle.
If the neuron position is edited this is indicative of a neurological disorder.

Question 15

What is the neocortex? What are its layers, from immature to mature

Answer 15

The outermost part of the cerebral cortex.
VI: Ventricular zone
V: Sub-ventricular zone (pop by intermed neural progenitor cells)
IV: Mantle zone (white matter)
III: Cortical plate (gray matter)
II: Marginal zone
I: Molecular layer

Question 16

What is the cerebellum? How does it develop?

Answer 16

It has the ventricular zone, the mantle zone, the internal granular layer, the purkinje cell layer, the marginal zone, and the external granular layer.
Cerebellar granular cells first migrate to the external granular layer from the rhombic lip where they proliferate, before migrating radially to the internal granular layer.

Question 17

How are the different parts of the brain distinguished? What cell types are between these layers?

Answer 17

They’re distinguished by epithelial layers and ependymal cells are between them (which are a derivative of Neuroepithelial Cells (stem cells))

Question 18

What do Neurons do?

Answer 18

Neurons conduct electrical potentials along their axons to control the functions of the body, and communicate through synapses. They may be defined by their neurotransmitters. Glutamate is excitatory and GABA is inhibitory, and axons can extend extreme distances.

Question 19

What are the 3 derivatives of Radial Glia Cells?

Answer 19

Neurons, Astrocytes, and Oligodendrocytes

Question 20

What do astrocytes do?

Answer 20

They form the blood brain barrier and regulate cerebral blood flow, have roles in synaptogenesis (trophic support and synapse elimination), gliotransmission and metabolic regulation, inflammation response and injury repair (astrogliosis)

Question 21

What do oligodendrocytes do?

Answer 21

They myelinate axons to insulate them and facilitate electrical conduction, provide trophic support to neurons, and are the last major cell type to form in development.

Question 22

What do microglia do? Where do they originate?

Answer 22

They originate from progenitor cells in the yolk sac, they’re tissue resident macrophages in the brain (part of immune response). They are needed for synapse formation, elimination, and maintenance.

Question 23

Does neural development stop at birth?

Answer 23

No. Embryonic rates of neurogenesis continue for a few years after birth, neurons continue to be produced from stem cells in the adult brain, and gliogenesis and myelination occur during puberty and early adulthood. Human neural development is considered complete around 25, and synaptic connections are refined after birth and strengthened and weakened by external stimuli and experiences.