L2- Cellular organisation of the nervous system

Question 1

What did Golgi do? (the person)

Answer 1

He believed that neutrites were fused together to form a network in the brain.
He used reduced silver stain to show cells in detail. First time seen so clearly.

Question 2

What was Cajal’s neurone doctrine?

Answer 2

Each neurone is a discrete cell.

Cajal also came up with the principle of dynamic polarisation.
Principle of connectional specifity

Question 3

What is the disadvantage of electron microscope?

Answer 3

Cells have to be dead

Question 4

What’s the main principle of fluorescence (immunofluorescene) labelling methods?

Answer 4

• Prepare selective antibody or drug tagged with fluorescent label
• Add to tissue and allow to bind
• Wash off excess
• Image shows distribution of fluorescence (corresponding to target protein’s distribution)

Question 5

WHat does the development of confocal microscopes allow?

Answer 5

Examination of live cells in 3D (two eyes so 3d)
Can see the physiology alive

BUT HAS LOW RESOLUTION- 0.1 micrometre (um)

Question 6

What are the 2 types of cell in the nervous system?

Answer 6

Neurones

Glia- support, can divide, involved in signalling

Question 7

Which glia are present in the CNS and PNS?

Answer 7

PNS- Schwann Cells

CNS- Astrocytes (astroglia)
Oligodendrocytes
Microglia

Question 8

What do astrocytes do?

Answer 8

Regulate composition of extracellular fluid

Question 9

What do microglia do?

Answer 9

Phagocytic/immune function

They can migrate

Question 10

What do ependymal cells do?

Answer 10

Line ventricles and direct cell migration during brain development.

Question 11

What do oligodendrocytes and Scwann cells do?

Answer 11

Myelinate axons of neurones.
Schwann- PNS and only single axon
Oligo- CNS and many axons

Question 12

What are axons and dendrites specialised for?

Answer 12

Axons- specialised for transmission of information

Dendrites- specialised for receipt of information

Question 13

What are the roles of neuronal cytoskeleton?

Answer 13

1. structural support
2. transport cargo to and from axons and dendrites
3. tethering of components at membrane surface

Question 14

Where’s the neuronal cytoskeleton?

Answer 14

Run longitudinally down axons and dendrites

Big 20nm wide tubulin polymers

Question 15

What do unipolar, bipolar and multipolar neurones look like?

Answer 15

Unipolar- long string with head comes up from the middle away from the axon
Bipolar- axon,string,axon
Multipolar- lots of bits coming out of the head. But one main axon.

Question 16

Where are interneurones?

Answer 16

Between sensory and motor neurones

Question 17

What is Alzheimer’s disease characterised by?

Answer 17

-Neurofibrils, dead and dying neurones

Neurfibrillary plaques of a-beta protein that all chunk together.