Synaptic Transmission

Question 0

What is the neurone distance in electrical transmission?

Answer 0

3.5nm

Question 1

Electrical transmission involves what structures?

Answer 1

Gap junctions

Question 2

Give the structure of gap junctions.

Answer 2

Connected by hemichannel connexons, made up of 6 connexin subunits

Question 3

What aspects can modulate gap junction alterations?

Answer 3

pH, neurotransmitter, and intracellular calcium

Question 4

Electrical transmission allows synchronisation, how does this aid and hinder transmission?

Answer 4

Allows neurones to act in the same way. But over synchronisation can cause seizures

Question 5

Chemical transmission involves the crossing of a synapse that is how large?

Answer 5

30-50nm

Question 6

How long does it take for the transmission to take place?

Answer 6

0.3-5ms

Question 7

What is the chemical involved in transmission?

Answer 7

Neurotransmitter

Question 8

Which neurotransmitters are synthesised in the axon terminal?

Answer 8

Amino acid and amine NTs

Question 9

Where are peptide hormones produced?

Answer 9

In the cell body, via ribosomes on RER

Question 10

How do peptide hormones travel from the cell body to the axon terminal?

Answer 10

In secretory granules via axoplasmic transport

Question 11

How are neurotransmitters stored in the axon terminal?

Answer 11

In secretory granules near the active zones

Question 12

What triggers the release of neurotransmitters from the axon terminals?

Answer 12

A rise in intracellular calcium due to influx

Question 13

How are neurotransmitter removed from the synapse?

Answer 13

Reuptaken, enzymatically broken down, or diffused away

Question 14

Give 5 examples if amine neurotransmitters.

Answer 14

Dopamine, noradrenaline, adrenaline, histamine and serotonin

Question 15

Which neurotransmitters are considered amino acids?

Answer 15

GABA, glutamate and glycine

Question 16

For a messenger to be considered a neurotransmitter is must posses what 5 proportions?

Answer 16

Synthesised in the neurone, present in the presynaptic terminal, exert effect on postsynaptic neurone, produce the same effect exogenously and have a mechanism of removal

Question 17

What are the two types of synaptic vesicles called and how do they differ?

Answer 17

Small clear vesicles (40-60nm) and large dense core vesicles (90-250nm)

Question 18

What is it described as when a neurone contains both types of synaptic vesicle?

Answer 18

Co-existence

Question 19

What does the term co-transmission mean?

Answer 19

A neurone that can synthesise and release more than one transmitter

Question 20

Where are voltage gated calcium channels concentrated in synaptic terminals?

Answer 20

Near the active zones

Question 21

How do synaptic vesicles fuse to the membrane for exocytosis?

Answer 21

Via SNARE proteins

Question 22

Which SNARE proteins are membrane bound?

Answer 22

SNAP-25 and syntaxin

Question 23

Which SNARE protein does synaptobrevin bind to?

Answer 23

SNAP-25

Question 24

Which SNARE protein does synaptotagmin bind to, and what is it’s secondary function?

Answer 24

Syntaxin and it is a calcium sensor

Question 25

What type of potential can occur without the arrival of an action potential?

Answer 25

A miniature end plate potential (MEPP)

Question 26

What does quanta release mean?

Answer 26

It is the spontaneous release of one synaptic vesicle due to a MEPP

Question 27

What are the two types of receptors on the postsynaptic membrane?

Answer 27

Metabotropic (GPCR) and ionotropic (LGIC)