Neurotransmitters I, synthesis storage and degradation

Question 1

When was it discovered that there were breaks (synapses) in the nervous system and that it wasn’t a syncitium?

Answer 1

1888-1934

Question 2

Fist small molecule transmitter to be identified?

Answer 2

ACh

Question 3

How was ACh discovered?

Answer 3

Took a isolated frogs heart w/ vagus nerve intact
If stimulated nerve could influence muscle contraction in the heart
Could transfer solution of stimulated heart to a heart that didnt have a vagus nerve, could mimic the change in muscle contraction and heart rate

Question 4

What did Otto Loewi show?

Answer 4

The nerve was releasing smthn soluble that was involved in heart stimulation

Question 5

Axodendritic synapse?

Answer 5

Axon onto dendrite

Question 6

Neuromuscular synapse?

Answer 6

Neuron onto muscle cell/peripheral tissue

Question 7

Basic signalling sequence?

Answer 7

Presynaptic AP Depolarisation of synaptic terminal Release of chemical transmitter Postsynaptic signal

Question 8

What are most chemical transmitters in the mammalian nervous system derived from?

Answer 8

AAs

Question 9

Why is there a v strong link between neurotransmission and cellular metabolism?

Answer 9

Lots of NTs are synthesised via metabolism–> i.e. AAs

Question 10

How many NTs can a given synapse use?

Answer 10

1

Question 11

Diff types of synapse?

Answer 11

Glutamatergic, GABAergic, cholinergic, noradrenergic, dopaminergic, serotonergic

Question 12

Why does the NT a synapse uses define it?

Answer 12

Synapses can only use one NT

Question 13

Which signalling molecules can a synapse use more than one of?

Answer 13

Neuropeptides

Question 14

WHich small molecule transmitter is a purine?

Answer 14

ATP

Question 15

Subdivision of biogenic amine NTS?

Answer 15

Catecholamines, indoleamine, imidazoleamine

Question 16

What are the catecholamines?

Answer 16

Dopamine, norepinephrine, epinephrine

Question 17

What is the indoleamine?

Answer 17

5HT

Question 18

What is the imidazoleamine?

Answer 18

Histamine

Question 19

What are the AA small molecule transmitters?

Answer 19

Glutamate, aspartate, GABA

Question 20

What are the catecholamines derived from?

Answer 20

Tyrosine

Question 21

What is 5HT derived from?

Answer 21

Tryptophan

Question 22

Criteria to be a small molecule transmitter?

Answer 22

Enzymes 4 synthesis present in nerve terminal
Storage in secretory vesicles
Release into synapse
Reception–> receptors
Removal–> terminating action

Question 23

Life cycle of a transmitter?

Answer 23

1. Synthesis
2. Storage/ Packaging
   3.Regulated Release
   4.Detection/ Signalling
3. Reuptake/ Degradation

Question 24

Where can transmitter receptors be?

Answer 24

Postsynaptic, presynaptic, on neighbouring cells

Question 25

Ways of removing transmitter from synapse?

Answer 25

Reuptake by neighbouring/Pre N cells Degradation in the synapse

Question 26

Where are transmitter degradation enzymes?

Answer 26

Tethered to membranes w/ lipid anchors

Question 27

How is glutamate packaged into vesicles?

Answer 27

Proton driven active transporters

Question 28

Why are active transporters needed to package glutamate into vesicles?

Answer 28

Need to drive the transmitter against conc grad to fill vesicle w/ a high enough conc of transmitter

Question 29

Glutamate transporter on vesicular membrane name?

Answer 29

VGluT (vesicular glutamate transporter

Question 30

Relationship between vesicular glutamate transporter and glutamate reuptake transporter?

Answer 30

Structurally unrelated