test 2 (neurotransmitters) Flashcards

1
Q

What are the three criteria that make something a neurotransmitter (NT)?

A
  • Present in the presynaptic neuron
  • Must be released during synaptic activity
  • Must bind receptors on the postsynaptic neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are co-transmitters?

A

A neuron can synthesize and release more than one type of neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the categories of neurotransmitters (NTs)?

A
  • Small Molecules (e.g. acetylcholine, amino acids, biogenic amines, purines)
  • Neuropeptides or peptides (e.g. enkephalins, gastrin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is acetylcholine (ACh)?

A

1st neurotransmitter discovered
Used in NMJ and ganglionic synapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is acetylcholine synthesized?

A

From acetyl-CoA and choline by choline acetyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is acetylcholine metabolized?

A

To acetate and choline by acetylcholinesterase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is acetylcholine loaded into synaptic vesicles?

A

Via a vesicular transporter (VAChT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the two types of acetylcholine receptors?

A
  • Ionotropic (nAChRs)
  • Metabotropic (mAChRs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What activates ionotropic ACh receptors?

A

Nicotine (agonist); inhibited by curare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where are ionotropic ACh receptors located?

A
  • Neuromuscular junction
  • Autonomic ganglia
  • Adrenal medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of response do ionotropic ACh receptors mediate?

A

Excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What activates metabotropic ACh receptors?

A

Muscarine; inhibited by atropine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the targets of metabotropic ACh receptors?

A
  • Smooth muscle
  • Glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What channels do some metabotropic ACh receptors activate?

A
  • GIRK channels (inhibitory)
  • Ca2+-regulated K+ channels (excitatory)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is glutamate (Glu)?

A

Main excitatory neurotransmitter in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is glutamate synthesized?

A

From glutamine by glutaminase

17
Q

How is glutamate loaded into synaptic vesicles?

A

Via vesicular glutamate transporters (VGLUTs)

18
Q

How is glutamate taken up by neighboring glial cells?

A

Via excitatory amino acid transporter (EAAT)

19
Q

What are the types of ionotropic glutamate receptors?

A
  • AMPA (fast response)
  • Kainate (fast to start, slower near end)
  • NMDA (slow response)
20
Q

What is the role of NMDA receptors?

A

Channel pore admits Ca2+, Na+, and K+; voltage dependent

21
Q

What blocks the NMDA channel?

A

Mg2+ blocks the channel; depolarization pushes Mg2+ out

22
Q

What is gamma-aminobutyric acid (GABA)?

A

Main inhibitory neurotransmitter in the brain

23
Q

What is the synthesis pathway for GABA?

A

Glucose -> glu -> GABA

24
Q

How is GABA taken up from the synaptic cleft?

A

Via Na+-dependent co-transporters (GAT)

25
How is GABA loaded into synaptic vesicles?
Via the vesicular inhibitory amino acid transporter (VIAAT)
26
What are the types of GABA receptors?
* Ionotropic (GABA-A R) * Metabotropic (GABA-B)
27
What type of channel does the GABA-A receptor form?
GABA-gated ion channel for Cl-
28
What is the effect of GABA-A receptor activation in young individuals?
Excitatory (Cl- outflux)
29
What is the effect of GABA-A receptor activation in mature individuals?
Inhibitory (Cl- influx)
30
What does GABA-B receptor activation do?
* Activates K+ channels * Inhibits Ca2+ channels
31
How is glycine (Gly) synthesized?
From serine by serine hydroxymethyltransferase
32
How is glycine packaged into vesicles?
By VIAAT (same as GABA)
33
How is glycine removed from the synaptic cleft?
By glycine transporters
34
What type of receptor does glycine have?
Ionotropic (ligand-gated Cl- channels)
35
What inhibits glycine receptors?
Strychnine