Lecture 7: CNS Neurotransmitters

Question 1

Where are small molecule (classical) neurotransmitters made?

Answer 1

synapse

Question 2

Where are peptide (non-classical) neurotransmitters made?

Answer 2

nucleus (cell body)

Question 3

What are three classes of small molecule neurotransmitters and examples of each?

Answer 3

1. acetylcholine
2. Amino Acids (glutamate, GABA, glycine)
3. Biogenic amines (dopamine, norepinephrine, seratonin)

Question 4

How long are neuropeptides?

Answer 4

3-36 AA

Question 5

What happens to small molecule neurotransmitters after synthesis in presynaptic terminal? What does the site of synthesis afford?

Answer 5

• packaging into vesicles

- can respond rapidly to increased demand

Question 6

What happens to neuropeptides after synthesis in the cell body? What effect does the site of synthesis have on their ability to respond to demand?

Answer 6

• packaged into vesicles –> transported to nerve termina via fast axonal transport
• can’t respond quickly
• release must be carefully regulated to prevent deletion

Question 7

What are the two types of neurotransmitter receptors?

Answer 7

1. Ionotropic = ligand-gated ion channels

2. Metabotropic = G-protein-coupled receptors

Question 8

Different subunit composition will always alter the ____ of neurotransmitter receptors, and different _____ express receptors with different _____.

Answer 8

• function
• neuronal subtypes
• subunit compositions

Question 9

Which type of neurotransmitter receptor is slower? Why?

Answer 9

Metabotrophic - uses 2nd messengers

Question 10

Ach is found at the neuromuscular junction (NMJ) and at synapses in ganglia of visceral motor system in the ____

Answer 10

PNS

Question 11

Ach is found at the interneurons in brainstem and forebrain, and at large neurons in the basal forebrain which project to cerebral cortex in the _____

Answer 11

CNS

Question 12

Describe synthesis of Ach

Answer 12

enzymatic from acetyl-CoA and choline

Question 13

describe packaging of Ach

Answer 13

vesicular Ach transporter packages Ach into vesicles

Question 14

Where does synthesis, packaging, and removal of Ach (small molecule neurotransmitter) happen?

Answer 14

synapse

Question 15

describe removal of Ach

Answer 15

cleaved to acetate and choline by acetylcholinesterase

Question 16

Are ionotrophic and metabotrophic receptors of Ach excitatory or inhibitory?

Answer 16

• ionotrophic = excitatory

- metabotrophic = either - depends on G protein

Question 17

What causes myasthenia gravis?

Answer 17

• autoimmune disease against muscle nAchR

- altered stucture of AchR at neuromuscular junction

Question 18

what are 4 treatments for myasthenia gravis?

Answer 18

• cholinesterase inhibitors (Ach stays longer, more chance to activate receptor)
• thymectomy
• corticosteroids
• immunosuppressants

Question 19

In a stroke, O2 deprivation slow _____ reuptake. This creates great interst in using ____ to block excitotoxic nerve damage after stroke

Answer 19

• glutamate

- glutamate receptor antagonists

Question 20

Is glutamate excitatory or inhibitory?

Answer 20

excitatory

Question 21

GABA and glycine are major _____ in the CNS

Answer 21

inhibitory neurotransmitters

Question 22

What is the rate-limiting enzyme in catecholamine synthesis?

Answer 22

• tyrosine hydroxylase

- DOPA –> dopamine

Question 23

What is the major transmitter of the sympathetic nervous system?

Answer 23

norepinephrine

Question 24

What class of neurotransmitters are involved in many psychiatric disorders?

Answer 24

biogenic amines

Question 25

where are neuropeptides synthesized and processed?

Answer 25

ER

Question 26

What kind of neurotransmitters deal with emotions, pain, and stress?

Answer 26

neuropeptides

Question 27

What are the 5 catogories of neuropeptides based on AA sequence?

Answer 27

brain-gut, opioid, pituitary, hypothalmic-releasing, misc