MT - Neurotransmitters and Receptors

Question 1

Give some examples of small-molecule neurotransmitters.

Answer 1

Any of: Acetylcholine, glutamate, GABA, glycine, aspartate, dopamine, norepinephrine, serotonin, etc.

Question 2

Give some examples of neuropeptide neurotransmitters.

Answer 2

Any of: vasopressin, somatostatin, oxytocin,angiotensin II, etc.

Question 3

What are 3 examples of small molecule neurotransmitters that aren’t contained in vesicles?

Answer 3

1. Endocannabinoids (lipid soluble)
2. Nitric Oxide (gas)
3. Carbon monoxide (gas)

Question 4

What is the rate limiting step during dopamine production?

Answer 4

Tyrosine hydroxylase.

Question 5

Where in the brain are cholinergic neurons localized?

Answer 5

The nucleus accumbens, medial septum, nucleus basalis, medial habenula, laterodorsal tegmental nucleus (LDT), etc.

Question 6

Where in the brain are noradrenergic neurons localized?

Answer 6

In the locus coerulus.

Question 7

Where in the brain are the sorotinergic neurons localized?

Answer 7

In the Raphe nucleus

Question 8

What is the prefix used to denote subunits of the AMPA receptors?

Answer 8

“Glu”.

Question 9

What is the prefix used to denote subunits of the NMDA receptors?

Answer 9

“Glu”.

Question 10

What is the prefix used to denote subunits of the Kainaite receptors?

Answer 10

“Glu”.

Question 11

What is the prefix used to denote subunits of the serotonin receptors?

Answer 11

“5-HT”.

Question 12

What is the prefix used to denote subunits of the purine receptors?

Answer 12

“P2X”.

Question 13

What differentiates GABAa from GABAb

Answer 13

GABAa: ligand gated ion channel
GABAb: GPCR (metabotropic)

Question 14

What are the 3 types of Gα subunits?

Answer 14

1. Gα s
2. Gα i/o
3. Gα q

Question 15

What does Gα s protein binding cause?

Answer 15

Activates adenylate cyclase (AC), which produces cAMP and stimulates protein kinase A (PKA).

Question 16

What does Gα i/o protein binding cause?

Answer 16

Inhibits adenylate cyclase (AC), which stops producing cAMP and therefore inhibits protein kinase A (PKA).

Question 17

What does Gα q binding cause?

Answer 17

Activation of phospholipase C (PLC-β).

Question 18

What are some examples of secondary messengers?

Answer 18

Any of: calcium, cGMP, cAMP, phosphatidyl inositol.

Question 19

What enzyme synthesizes cAMP?

Answer 19

Adenylate cyclase (AC).

Question 20

What enzyme synthesizes phosphatidyl inositol?

Answer 20

Phospholipase C (PLC-β).

Question 21

What do muscarinic receptors control?

Answer 21

Heart contractility.

Question 22

When a muscarinic receptor in the heart is activated, what do the associated G-proteins do?

Answer 22

Gα subunit: dephosphorylates (closes) calcium channels

Gβ/γ subunit: activates (opens) potassium channels

Question 23

Through what receptor/messenger/signalling pathway does epinephrine act on the heart? Elaborate.

Answer 23

Activates GPCRs -> AC -> cAMP -> PKA -> open Na+ and Ca2+ channels.

Question 24

What effect does epinephrine signalling have on the rate of depolarization in the heart? What is the overall physiological effect?

Answer 24

Increases rate of depolarization and therefore heart rate.

Question 25

NMDA receptors are highly permeable to _____.

Answer 25

Calcium.

Question 26

What is another term used to describe an NMDA receptor?

Answer 26

A “coincidence detector”.

Question 27

Extracellular Mg2+ blocks ____ receptors.

Answer 27

NMDA.

Question 28

Where does GABA bind on the GABAa receptor?

Answer 28

At the αβ interfaces.