VC - Molecular Neuroscience

Question 1

Where does molecular neuroscience occur?

Answer 1

Between the molecular and sub-cellular level

Question 2

What are some key statistics about the complexity of the brain?

Answer 2

• 30,000 genes
• 100, 000 proteins
• 86 billion neurons
• 10-100 trillion synapses

It operates on a micro-millisecond time scale and can retain or forget information for 10 seconds to 70 years

Question 3

Is the brain a vital organ?

Answer 3

No, the brain is not vital as you can be brain dead and still survive

Question 4

What are 4 major diseases associated with the brain?

Answer 4

1. Alzheimer’s
2. Autism
3. Depression
4. Epilepsy

Question 5

What are the major promoters controlling nerve function?

Answer 5

Glutamate:
- Major excitatory transmitter
- Natural amino acid

GABA:
- Major inhibitory transmitter
- Synthesised amino acid

Question 6

What enzyme converts Glutamate –> GABA?

Answer 6

Glutamic acid decarboxylase (GAD)
- Removes the carboxyl group on glutamate

Question 7

What is the GAD gene recognised by?

Answer 7

Transcription factors to ensure gene is selectively expressed in GABA neurons

Question 8

What is the polarity of neuronal processes?

Answer 8

• axon giving the presynaptic nerve terminal
• dendrite giving the postsynaptic nerve terminal

Question 9

What are the basic features of microtubules, intermediate filaments and actin filaments?

Answer 9

Microtubules
- 25-nm diameter
- Composed of alpha/beta dimers (50kDa each)
- Dynamic structure
- Build hollow tube
- Add and subtract from each + and - end

Intermediate filaments
- 10-nm diameter
- Dimer with head and tail
- Ring like structure

Actin filaments
- 7-nm diameter
- Composed of G-actin monomers which make F-actin filaments
- G-actin monomers → F-actin filaments

Question 10

How are microtubules orientated in the axon structure?

Answer 10

Orientated unidirectionally

• +ve end grows towards the presynaptic terminal
• -ve end grows towards cell body

Question 11

How are microtubules orientated in the dendrite structure?

Answer 11

Orientated bi-directionally

Question 12

What filament stabilises axons?

Answer 12

Neurofilament

Question 13

What is the role of the actin cytoskeleton in neurons?

Answer 13

The actin cytoskeleton is often associated with a cortical network enriched in the terminal region of neurons