Lecture Content

Question 1

What is the layout of a multipolar neuron?

Answer 1

1 axon, multiple dendrites.

Question 2

What is the layout of a bipolar neuron?

Answer 2

1 axon, 1 dendrite which then branches.

Question 3

What is the layout of a pseudo-unipolar neuron?

Answer 3

1 process (containing cell body) which immediately branches.

Question 4

What is the layout of a unipolar neuron?

Answer 4

Dendrites extend from the axon.

Question 5

1. What do anterograde microtubules transport?

2. What direction and speed can this transport occur?

Answer 5

1. NTs, structural elements, metabolic components
2. Cell body to axon via kinesins.
   FAST (1-4cm/day).
   SLOW movement (0.05-1cm/day) can also occur.

Question 6

1. What do reterograde microtubules transport?

2. What speed and direction can this transport occur?

Answer 6

1. Aging mitochondira and vesicles. Signals indicating damage and repair requirement.
2. Axon to cell body via dynesins.
   FAST (5-25cm/day)

Question 7

What does DTI stand for, and what can it show?

Answer 7

Diffusion Tensor Tractography. Type of MRI showing neuronal pathways through the brain- outlining connectivity pathways.

Question 8

How many different neuronal inputs CONVERGE onto one neuronal cell body?

Answer 8

10,000

Question 9

How many outputs are there from any neuron?

Answer 9

100s

Question 10

Which neuroglial cells promote axon regeneration?

Answer 10

Schwann cells

Question 11

How many axons can one oligodendrocyte myelinate?

Answer 11

40-50

Question 12

What type of cell regulates glutamate levels in the synapse via its glutamate transporter activity?

Answer 12

Astrocytes

Question 13

Which cell type forms the Glial Scar after injury?

Answer 13

Astrocytes

Question 14

How do astrocytes regulate the BBB?

Answer 14

Via formation of the glial limitans

Question 15

Which ion concentrations do astrocytes regulate?

Answer 15

K+, H+, H20

Question 16

What types of astrocytes exist, and what is their structure, location and function?

Answer 16

1. Fibrous
   Long and stretched;
   Grey matter;
   Homeostatic role
2. Protoplasmic
   Star Shaped;
   White matter;
   Provide axon stability and support

Question 17

What two states can microglia exist in?

Answer 17

1. Multiple processes extending (with ATP receptors)

2. Rounded (phagocytic)

Question 18

What is the most abundant form of ependymal cell and what is its function?

Answer 18

Ependymocytes. Form an epithelial lining, containing cilia on their apical surface for CSF circulation, and microvilli for CSF absorption

Question 19

Where are tancytes found, and what is their function?

Answer 19

IIIrd ventricle. Act as sensors for molecules/secreted hormones within CSF

Question 20

What is the function of choroid plexus cells? What type of neuroglial cell are they?

Answer 20

CSF production and secretion in all brain ventricles.

Ependymal cells

Question 21

How to Schwann cells promote axon regeneration?

Answer 21

1. Upregulate laminin and neurotrophin (permissive to axon regeneration)
2. Rapidly phagocytose myelin debris.

Question 22

What is the role of a satellite cell, and where are they found?

Answer 22

Provide structural and metabolic support to neurons. Foudn within the DRG and sympathetic ganglia.

Question 23

What are the 5 ways of interfering with neuronal transmission?

Answer 23

Synthesis
Storage
Release
Receptor
Removal

Question 24

How is L-Dopa used, and in which disease?

Answer 24

L-dopa is used to treat Parkinson’s disease. It promotes dopamine synthesis and release in remaining healthy dopaminergic neurons.

Question 25

How does amphetamine interfere with neuronal tranmission?

Answer 25

STORAGE!
Amphetamine disrupts noradrenaline storage, resulting in leakage into the nerve terminals and synapse.
It also blocks MAO (monoamine oxidase), which would otherwise breakdown the free NA in the nerve terminal.

This results in an increased level of NA in the synapse and interacting with post-synaptic receptors.

Question 26

How does Conotoxin interfere with neuronal tranmission?

Answer 26

RELEASE!
Conotoxin blocks vgccs, hence inhibiting Ca entry into the nerve terminal, which would otherwise allow NT exocytosis into the synapse.
This produces powerful analgesia.