19.6 Flashcards Preview

Week 19 > 19.6 > Flashcards

Flashcards in 19.6 Deck (30):
1

The embryo is a flat disc of cells of three layers: ___, ___ and ___

Ectoderm, mesoderm and endoderm.

2

The neural fold closes at different places at different times - defects of neural fold closure include ___ ___ and ___.

Spina bifida and anencephaly.

3

Prosencephalon = ___
Mesencephalon = ___
Rhombencephalon = ___

Forebrain
Midbrain
Hindbrain

4

Telencephalon = ___ and ___ ___.

Cortex and basal ganglia.

5

Diencephalon = ___ and ___

Thalamus and hypothalamus.

6

Derivatives of the neural crest include:

Peripheral nervous system (e.g. DRG, SNS/PNS ganglia, enteric ganglia, Schwann cells)!
And melanocytes, muscle, cartilage and bone of head/face, dentine.

7

Neural crest cells migrate down to gut to populate the enteric nervous system - failure of cells to migrate to end of gut tube causes ___ disease.

Hirschsprung's

8

The neuroepithelium of the neural tube is ___ cell thick.

One/single.

9

In the development of the brain, stem cells start in the ___ zone, and proliferate adjacent to the ___ space.

Ventricular zone and proliferate adjacent to the ventricular space.

10

New cells forming at the ventricular surface migrate ___, out to skin and form new layers on the outer surface of the brain.

Radially

11

___ glia are a population of neuroepithelium cells that maintain connection with the ___ surface and the surface under the ___.

Radial glia
Connection with ventricular surface and surface under the ectoderm.

12

___ glia act as a guide for the migration of new neurons.

Radial

13

Radial glia are ___ cells, form some cells that form layers of brain.

Stem cells.

14

___ is a guide molecule that directs cells in migration from ventricular zone to outside of brain.

Reelin

15

Mutation of ___ results in disorders of layers of cortex

Reelin mutation -> profound mental retardation, less white matter and more grey matter.

16

Lissencephaly is due to mutation of the ___ gene.

Doublecortin (DCX) gene.

17

In ___, there is complete disorganisaion of the cortex - no white or grey matter, large ventricles, less neurons and failure of migration.

Lissencephaly

18

Fragile X syndrome is due to mutation of the ___ ___ ___ ___ gene

Fragile X mental retardation gene (FMR1).

19

There is evidence for a strong developmental component in the pathogenesis of ___

Schizophrenia

20

In the neural tube there is a __ plate and a ___ plate that is close to the ___.

Roof plate.
Floor plate, close to the notochord.

21

The notochord releases ___ ___ that diffuses out in all directions.

Sonic hedgehog

22

Sonic hedgehog interacts with cells in the ___ plate and induces them to change to ___ plate cells.

Floor plate -> floor plate cells by sonic hedgehog.

23

Floor plate cells in the floor plate release sonic hedgehog - this forms a gradient that is highest in concentration at the floor plate - neurons adjacent to the floor plate form ___ neurons in the ___ part of the spinal cord.

Motor neurons in the ventral part of the spinal cord.

24

Motor neurons release ___ ___ ___ that diffuses out and induces cells dorsal to motor neurons to form ___.

Motor neuron factor.
Interneurons

25

Growth of axons is directed by ___ ___ composed of ___ and ___.

Growth cones of actin and microtubules.

26

Growth cones pull axons to high concentrations of ___ (abbrev.).

NGF (nerve growth factor).

27

The ___ ___ refers to the time frame for refinement of synaptic connections

Critical period

28

Refinement

Permanent changes to form a mature and functional nervous system

29

If you cover a single eye of a kitten from birth and uncover it at 6 months, the kitten has ___ blindness.

Cortical i.e. normal retina and LGN, but cortex does not process information.

30

If you cover both eyes of a kitten from birth and uncover them at 6 months, the kitten is ___ blind.

NOT BLIND
Therefore, refinement depends on relative neural activity, NOT absolute!