Neurotransmitters and specific antidepressants

Question 1

What are the two broad categories of neurotransmitters?

Answer 1

1. Small molecule

2. Neuropeptide

Question 2

What type of neurotransmitters are biogenic amines?

Answer 2

small molecule

Question 3

What are the 4 characteristics to be a Neurotransmitter?

Answer 3

1. present in the presynaptic neuron
2. released in response to presynaptic
   depolarization
3. receptors for the substance must be
   present of the postsynaptic cell
4. Has a method for signal termination

Question 4

List the Catecholamines

Answer 4

1. Norepinephrine
2. Epinephrine
3. Dopamine

Question 5

List the Indoleamines

Answer 5

serotonin

Question 6

What are Indoleamines and Catecholamines?

Answer 6

Monoamines

Question 7

what type of NT are Gamma-aminobutyric acid (GABA), glutamate, and glycine?

Answer 7

Amino acids

Question 8

What type of NT is Acetylcholine?

Answer 8

Quaternary amine

Question 9

where is Acetylcholine found?

Answer 9

– Skeletal muscle
– Vagus nerve and heart
– Autonomic nervous system – Central nervous system

Question 10

What are 2 important sybtypes of Acetylcholine receptors? where are the found?

Answer 10

– Nicotinic – ligand-gated ion channel, mainly in
muscle
– Muscarinic – metabotropic, found in ANS, CNS

Question 11

What are 2 important sybtypes of Acetylcholine? where are the found?

Answer 11

– Nicotinic – ligand-gated ion channel, mainly in
muscle
– Muscarinic – metabotropic, found in ANS, CNS

Question 12

List the Biogenic Amines

Answer 12

dopamine, norepinepherine, epinepherine, serotonin, histamine

Question 13

List the Biogenic Amines

Answer 13

dopamine, norepinepherine, epinepherine, serotonin, histamine

Question 14

Describe the general lifecycle of non-peptide neurotransmitters?

Answer 14

1. Precurser reacts with enzymes to produce neurotransmitter
2. Packages into vesicles
3. Released into synapse
4. Transporter brings them back into presynaptic neuron

Question 15

what is a cholinergic neurons?

Answer 15

a neuron that primarily uses Acetylcholine

Question 16

Where are cholinergic neuron cell bodies primarily located?

where do their axons project to?

Answer 16

Cell bodies located:

• spetal nuclei
• nucleus basalis

axons project to:
- forebrain (in particular hippocampus and cerebral cortex)

Question 17

Is Acetylcholine excitatory or inhibitory?

Answer 17

excitatory

Question 18

Biosynthesis of the catecholamines begins with which amino acid?

Answer 18

tyrosine

Question 19

How are catecholamines inactivated?

Answer 19

primarily through reuptake into the presynaptic nerve terminal

Question 20

Norepinephrine and epinephrine act on which two primary types of receptors

Answer 20

alpha and beta

Question 21

Dopamine exerts postsynaptic effects on which recpetors?

Answer 21

At least 6 in 2 categories

Question 22

What are the precursors to Acetylcholine?

Answer 22

Acetyl Co A and Choline

+ the enzyme choline acetyl transferase

Question 23

Excitatory neurotransmitters have what effect of the post synaptic neuron

Answer 23

depolarizing

Question 24

How is Acetylcholine terminated?

Answer 24

Broken down by an enzyme and its (acetate and choline)

by an enzyme called
Acetyl-cholin-esterase

then those compontents are brought back into the presynaptic neuron to create more acetlcholine

Question 25

Where are the cell bodies of norepinephrine neurons located?

Answer 25

in the brain stem, mainly in a structure in the pons called the locus coeruleus axons project widely throughout the brain to nerve terminals in the cerebral cortex, the limbic system, the hypothalamus, and the cerebellum also travel down the spinal cord, where they exert an analgesic action

Question 26

What are the 2 important subtypes of Acetlycholine recpetors?

Answer 26

Nicotinic – ionotpropic, mainly in muscle Muscarinic – metabotropic, found in ANS, CNS

Question 27

what enzymes catabolize dopamine and norepinepherine?

Answer 27

Mononamine Oxidase (MAO) and Catechol-O-Methy Transferase (COMT)

Question 28

Where do dopamine cell bodies originate? where do they send signals?

Answer 28

brain stem, sending axons both rostral (forward) to the brain and caudal (backward) to the spinal cord

Question 29

dopamine receptors are all?

Answer 29

metabotropic

Question 30

What type of NT is serotonin?

Answer 30

Indoleamines

Question 31

What is the amino acid precursor to serotonin?

Answer 31

tryptophan

Question 32

What are the two enzymes involved in serotonin production?

Answer 32

tryptophan hydroxylase and amino acid decarboxylase

Question 33

What are serotonin receptors called?

Answer 33

5-HT receptors

Question 34

which 5-HT receptor should drugs NOT interact with

Answer 34

5-HT 2B receptors are thought to cause heart problems, it has been nicknamed the “death receptor”

Question 35

What is the precurser to GABA? what enzymes are involved?

Answer 35

a different neurotransmitter (glutamate) enzyme glutamic acid decarboxylase

Question 36

How is glutamate synthesized?

Answer 36

many ways BUT important = the glutamine cycle - after glutamate has its effect in the synapse it is transported and converted to the inactive glutamine by astrocytes eventually it diffuses into the nerve terminal where it is converted back to glutamate

Question 37

What types of Glutamate receptors exist?

Answer 37

- ionotropic | - metabotropic

Question 38

For a glutamate NMDA receptor to be activated what needs to be present

Answer 38

glutamate but ALSO | either glycine or serine

Question 39

What is the full name of GABA?

Answer 39

Gamma Aminobutyric Acid

Question 40

Where are dopaminergic cell bodies located? Where do they project to (describe the 3 circuits we will focus on)

Answer 40

Located in: Substantia nigra and project to -> caudate nucleus of the basal ganglia and is involved in motor functions Located in: Midbrain (NEXT to Substantia nigra) and project to -> that project widely to the cerebral cortex and forebrain limbic system

Question 41

Where are norandrenergic cell bodies located? where do they project?

Answer 41

Located in: locus coeruleus and adjacent regions of the brain stem Project widely to the forebrain and cerebellum and to the brain stem and spinal cord.

Question 42

Serotonin involved in?

Answer 42

Regulation of sleep and wakefulness, mood, circadian rhythms, feeding behaviour, nausea, pain, blood pressure, motor control, sexual behaviour, impulsivity, aggression

Question 43

Histamine involved in?

Answer 43

Associated with arousal and attention in the CNS

Question 44

Norepinepherine involved in?

Answer 44

Associated with sleep and wakefulness, attention, and feeding behaviour

Question 45

Dopamine involved in?

Answer 45

Involved in motor control, motivation, reward, and reinforcement

Question 46

List the different types of antidepressants

Answer 46

1. TCAs: tricyclic antidepressants 2. MAOIs: monoamine oxidase inhibitors 3. Heterocyclic 4. SSRIs 5. SNRIs 6. NDRI (wellbutrin) 7. SEROTONIN-2 ANTAGONISTS/REUPTAKE INHIBITORS (SARIs)

Question 47

Mechanism of action of TCAs?

Answer 47

1. They block the presynaptic reuptake transporter for norepinephrine and serotonin. 2. TCAs block postsynaptic receptors for histamine and acetylcholine. Such blockade accounts for most of the side effects of this class of drugs.

Question 48

What is a major drawback of TCAs?

Answer 48

Blocks histamine: drowsiness Blocks acetylcholine, Blocks alpha adrenergic: drop in blood pressure +slow onset

Question 49

major drawback of MAOIs?

Answer 49

toxicity, need for dietary restrictions irreversable