Lecture 2

Question 1

What are the three layers of the neural plate?

Answer 1

mesoderm, ectoderm and endoderm

Question 2

What is the process of neuralation?

Answer 2

The neural plate becomes the neural tube

Question 3

What develops from the mesoderm?

Answer 3

Bones and muscle

Question 4

What forms from the endoderm?

Answer 4

Lining of organs

Question 5

What forms from the ectoderm?

Answer 5

The nervous system and skin

Question 6

What layer is the neural plate in?

Answer 6

Ectoderm

Question 7

What structures does the neural plate fold into?

Answer 7

Neural groove and neural fold

Question 8

What do the neural groove and neural folds fold to form?

Answer 8

The neural tube and neural crests

Question 9

What does the neural tube form?

Answer 9

The CNS

Question 10

What do the neural crests form?

Answer 10

The PNS

Question 11

Which end of the neural tube becomes differentiated to form 3 ventricles?

Answer 11

Rostal

Question 12

What are the 3 primary vesicles?

Answer 12

Forebrain, midbrain and hindbrain

Question 13

Which vesicle connects with the rest of the neural tube caudally and forms the spinal cord?

Answer 13

The hindbrain

Question 14

What vesicles form from the forebrain primary vesicle?

Answer 14

Two telencephalic vesicles, the diencephalon and the two optic vesicles

Question 15

What forms from the telencephalon?

Answer 15

The cerebral cortex

Question 16

What forms from the diencephalon?

Answer 16

The thalamus and hypothalamus

Question 17

What are the spaces between the telencephalon regions?

Answer 17

The lateral ventricles

Question 18

What are the 3 stages of neurone development?

Answer 18

proliferation, migration and differentiation

Question 19

How many layers of general neocortex are there?

Answer 19

6

Question 20

Where are neocortical neurones born?

Answer 20

The ventricular zone

Question 21

What type of cells does the ventricular zone give rise to?

Answer 21

Baby neurones- not differentiated yet

Question 22

What are the two layers of the vesicle wall?

Answer 22

Ventricular zone and marginal zone

Question 23

What is the external surface of the ventricles called?

Answer 23

The plial surface

Question 24

What happens when stem cells reach the plial surface?

Answer 24

They are told to divide/replicate DNA and return to the ventricular zone

Question 25

What are the two forms of stem cell division on the ventricular surface?

Answer 25

Symmetrical/vertical and asymmetrical/horizontal

Question 26

What does symmetrical division form?

Answer 26

2 radial glial cells with long processes reaching for the plail surface

Question 27

What does asymmetrical division form?

Answer 27

one radial glial cell, the top cell forms a neuronal precursor which migrates up in the neocortical layers.

Question 28

What is the structural fibre used by neuronal precursors for migration up the cortex?

Answer 28

The long processes of radial glial cells

Question 29

In what direction does the cortex develop?

Answer 29

From inside out- layer VI- I

Question 30

What determines when a cell stops migrating?

Answer 30

Gene expression and the environment

Question 31

What does the intermediate zone become?

Answer 31

The white matter

Question 32

What sits on top of the developing layers?

Answer 32

The marginal zone and cortical plate

Question 33

What sits below the developing layers?

Answer 33

The sublate and intermediate zone

Question 34

What causes microcephaly?

Answer 34

Impaired proliferation so reduced cell number. small brain with mixed up layers

Question 35

What is lissencephaly?

Answer 35

Smooth brain surface and sulci and gyri do not form. lots more cells mixed up

Question 36

What is polymicrogyria?

Answer 36

mixture of proliferation, migration and organisation deficits. Small fused gyri.

Question 37

What are new born neurones called?

Answer 37

Neuroblasts

Question 38

When do neuroblasts start differentiating?

Answer 38

At the cortical plate

Question 39

Once cells are differentiated, what are the three steps which occur before synapses are formed?

Answer 39

Pathway selection, target selection and address selection

Question 40

What is at the tip of a growing axon?

Answer 40

The growth cone

Question 41

What extends from the growth cone?

Answer 41

Lamellipodia

Question 42

What extends from lamellipodia?

Answer 42

Filopodia

Question 43

What does the growth cone secrete which allows the elongation of the axon?

Answer 43

Proteases which degrade fibrous proteins in the extracellular matrix

Question 44

Connections between what molecules allow elongation?

Answer 44

Integrins are on the surface which bind to laminins in the matrix.

Question 45

What molecules on growing axons bind to each other to pull each other along?

Answer 45

Cell adhesion molecules (CAMs)

Question 46

What is the name of the process where CAMs pull axons along?

Answer 46

Fasciculation

Question 47

What is the chemoaffinity hypothesis?

Answer 47

Neurones which originate from different areas have different CAMs on their surface which guide them to different target tissues which have different chemoattractant and repellents

Question 48

What is an example of an axon attractant?

Answer 48

Netrins

Question 49

What are the two receptors of Netrin-1?

Answer 49

DCC (attracts) and UNC5H (repels)

Question 50

As well as netrin, what are some other matrix molecules involved in axon guidance?

Answer 50

Semaphorins, ephrins and slits