Amine Neurotransmitters

Question 1

What are the main amine neurotransmitters in the CNS?

Answer 1

Noradrenaline (NA), Dopamine (DA), Serotonin (5HT), Acetylcholine (ACh), and Histamine

Question 2

What are the two categories of amine neurotransmitters?

Answer 2

Catecholamines (e.g., dopamine, noradrenaline) and Indoleamines (e.g., serotonin).

Question 3

Where do noradrenaline pathways in the CNS originate?

Answer 3

The locus coeruleus in the brainstem

Question 4

What are the main functions of noradrenaline in the CNS?

Answer 4

Arousal, mood regulation, attention, learning, memory, movement, and blood pressure control

Question 5

What enzymes degrade noradrenaline?

Answer 5

Monoamine oxidase (MAO) and Catechol-O-methyltransferase (COMT).

Question 6

What neurotransmitter is known as the “reward chemical”?

Answer 6

Dopamine (DA)

Question 7

Name the main dopamine pathways in the CNS

Answer 7

Nigrostriatal, Mesocorticolimbic and tuberoinfundibular pathways.

Question 8

What disorders are associated with dopamine dysfunction?

Answer 8

Parkinson’s disease, schizophrenia, and addiction.

Question 9

What enzymes degrade dopamine?

Answer 9

MOA and COMT

Question 10

What are the functions of serotonin (5HT) in the CNS?

Answer 10

Regulation of mood, sleep, appetite, and sensory transmission.

Question 11

What is the precursor to serotonin (5HT)?

Answer 11

Tryptophan

Question 12

Which enzyme is the rate-limiting step in serotonin synthesis?

Answer 12

Tryptophan hydroxylase

Question 13

What are the two main types of acetylcholine receptors?

Answer 13

Nicotinic (ionotropic) and muscarinic (GPCR)

Question 14

What are the key functions of acetylcholine in the CNS?

Answer 14

Arousal, learning, memory, and motor control.

Question 15

What enzyme inactivates acetylcholine?

Answer 15

Acetylcholinesterase (AChE)

Question 16

Where is histamine synthesised in the brain?

Answer 16

The tuberomammillary nucleus of the hypothalamus.

Question 17

What are the key roles of histamine in the CNS?

Answer 17

Arousal, attention, learning, memory, and regulation of feeding and energy balance.

Question 18

What are the two forms of COMT and where are they found?

Answer 18

Membrane-bound COMT (MB-COMT) in the brain and soluble COMT (S-COMT) in peripheral tissues.

Question 19

How do MAO inhibitors work as antidepressants?

Answer 19

They block the degradation of monoamine neurotransmitters, increasing their levels in the brain.

Question 20

What is the clinical significance of the mesocorticolimbic dopamine pathway?

Answer 20

It is involved in reward, emotion, and schizophrenia.

Question 21

What class of drugs is used to treat Parkinson’s Disease by inhibiting dopamine degradation?

Answer 21

MAO-B inhibitors and COMT inhibitors.

Question 22

How do SSRIs treat depression?

Answer 22

They block serotonin reuptake, increasing its availability at synapses.

Question 23

What neurotransmitters is linked to Alzheimer’s disease due to its role in learning and memory?

Answer 23

Acetylcholine (ACh)

Question 24

What type of histamine receptor antagonist is used as a sedative?

Answer 24

H1 antagonists that cross the blood-brain barrier (e.g. diphenhydramine).