The Brain And Neurodevelopment- Week Seven

Question 1

What are the 6 key stages of neurodevelopment?

Answer 1

Neurogenesis
Neuronal Migration
Cellular Differentiation
Synaptogeneis
Apoptosis
Synaptic Reorganisation

Question 2

What is the importance of neurodevelopment

Answer 2

All behavioural development is associated with N.D
Demonstrates how the brain changes in response to external stimuli
Shows how abnormalities occur and how these can be treated or prevented

Question 3

What is gastrulation?

Answer 3

The differentiation into 3 parts:
Ectoderm
Mesoderm
Endoderm

Question 4

What does the endoderm form?

Answer 4

Internal organs

E.g gut, liver, lungs

Question 5

What does the ectoderm form?

Answer 5

Central nervous system, peripheral nervous system and epidermis

Question 6

What does the mesoderm form

Answer 6

skeletal system
Muscles
Vascular region

Question 7

Describe the 3 steps in neurulation:

Answer 7

2 weeks after gestation- ectoderm fold in on itself
3 weeks after gestation- generates a neural plate, forming a neural groove
4 weeks after gestation- the neural groove deepens and develops into neural tube

Question 8

What does the neural tube contain?

Answer 8

Stem cells

Question 9

Describe the steps in Neurogenesis:

Answer 9

It occurs in the ventricular zone of the neural tube
It is when cell-proliferation occurs (cell birth) via mitosis
It is a regulated process, where the number of cells is pre-determined

Question 10

What is symmetrical division in Neurogenesis:

Answer 10

2 stem cells- increases size of ventricular zone

Question 11

What is asymmetrical division in Neurogenesis:

Answer 11

1 stem cell and 1 progenitor cell

Differentiate into neurons

Question 12

What happens during neuronal migration?

Answer 12

They new cells and neurons which are generated migrate towards the outer layers of cortex
This occurs rapidly during weeks 8-16, then slows down until week 25
There is both passive and active migration

Question 13

What is neuronal migration controlled by?

Answer 13

Genetic factors

Question 14

What might some developmental disorders be associated with?

Answer 14

Migration errors because some cells have specific places within the cortex

Question 15

What happens during cellular differentiation?

Answer 15

When the cells are in the location they need to be
Stem cells get turned into neurons or support cells
Which all have specific functions

Question 16

What is the function of oligodendrocytes?

Answer 16

To gradually increases the myelin sheath around the axon of neurons

Question 17

What happens during synaptogenesis?

Answer 17

Forming connections and networks between cells
Also occurs after post-natally
In the initial stages everything if connections but this isn’t very efficient, so some connections are made redundant

Question 18

What happens during apoptosis?

Answer 18

It is a programmed cell death to allow cells and connections to be made redundant that are not being used
Causes by an internal chemical process

Question 19

What happens during synaptic re-organisation?

Answer 19

Develop too many connections during young childhood
Do these are competitively pruned to allow the brain to be most efficient
Use it or lose it principle
Heavily influenced by external environmental issues

Question 20

What are the productive processes

Answer 20

Neural tube formulation
Neurogenesis
Differentiation
Migration, synoptogenesis

Question 21

What are the subtractive processes:

Answer 21

Apoptosis
Synaptic re-organisation
Competitive elimination
Synaptic pruning