Molecular Neuroscience

Question 1

Most common neurotransmitters in the brain?

Answer 1

Glutamate and GABA

Question 2

What is GABA?

Answer 2

Inhibitory neurotransmitter

Question 3

What is glutamate?

Answer 3

Excitatory neurotransmitter

Question 4

What enzyme produces GABA from glutamate?

Answer 4

Glutamate decarboxylase (GAD)

Question 5

Post and presynaptic terminals have a cytoskeleton made of….

Answer 5

Actin

Question 6

Microtubules are in dendrites and axons but what directions

Answer 6

Axons- unidirectionally

Dendrites- bidirectionally

Question 7

What filaments stabilise the axon

Answer 7

Neuro filaments

Question 8

How is cargo transported in neurones?

Answer 8

Kinesins

Question 9

How does a kinesin motor work?

Answer 9

2 kinesin form a dimer to form a motor protein kinesins move from negative to positive. This is done using the hydrolysis of ATP cycling to cause them to walk.

Question 10

What are kinesins attached to?

Answer 10

Microtubules

Question 11

How are sodium channels made?

Answer 11

Made of one protein sequence with 4 domain each making 1/4 of the pore. Each domain has a voltage sensor, this causes re-entry loops open and close dependent on charges.

Question 12

Sodium channels activation and deactivation thresholds

Answer 12

Activation: -50mv
Deactivation: 0mv

Question 13

How are potassium channels formed?

Answer 13

1 protein sequence with 4 domains making a tetramer. Each domain has a voltage sensor. Re-entry loops open and close depending on voltage.

Question 14

Potassium channel activation and deactivation?

Answer 14

Activation: 0mv
Deactivation: +50mv

Question 15

How does electrical transmission occur?

Answer 15

Signal is passed through ions that move through tight junctions in to postsynaptic neuron.

Question 16

How are tight junctions made for electrical synapses?

Answer 16

Made from heavy channels that are made of 6 domains each and when they line up creates a full conduit between cells

Question 17

Two types of synaptic transmission?

Answer 17

Chemical and electrical

Question 18

How does chemical synapse work?

Answer 18

Excitation of a neuron leads to Ca2+ release in the synaptic terminal. Ca2+ causes conformational change of a protein called synaptotagmin, this allows SNARE proteins to cause vesicles to fuse with plasma membrane releasing neurotransmitter

Question 19

What protein does Ca2+ bind to in chemical synapses?

Answer 19

Synaptotagmin

Question 20

What proteins promote vesicle fusion with plasma membrane? (Chemical synapse)

Answer 20

SNARE proteins

Question 21

How is a synaptic signal terminated?

Answer 21

By diffusion or reuptake or neurotransmitters

Question 22

What are major excitatory synapses?

Answer 22

Axo-dendritic synapse (use glutamate)

Question 23

What are major inhibitory synapses?

Answer 23

Axo-somatic synapses that utilise GABA

Question 24

Key features of glutamate receptors:

Answer 24

Made of four subunits to make an ion channel. Glutamate binding is on the outside. Inside binds to organising molecule PSD-95

Question 25

Key features of GABA receptors:

Answer 25

Made of 5 subunits with glycine bonding outside. It’s an anion channel. Binds to organising molecule gephyrin.

Question 26

How are synapses held together?

Answer 26

Neurexin and Neuroligins attach to each other holding synapse together.