Ch. 4 Module 2

Question 1

What is the most common excitatory neurotransmitter in the CNS?

Answer 1

Glutamate

Question 2

What is the most abundant inhibitory neurotransmitter in the CNS?

Answer 2

GABA

Question 3

What are GABA A receptors?

Answer 3

They are inotropic and have chloride channels.

Question 4

What are GABA B receptors?

Answer 4

They are metabotropic and they open potassium channels in the membrane.

Question 5

What are the 2 subclasses of monamines:

Answer 5

indoleamines & catecholamines

Question 6

catecholamines include

Answer 6

dopamine, norepinephrine

Question 7

What are catecholamines broken down by?

Answer 7

COMT & MAO

Question 8

Indoleamines include, and are broken down by what?

Answer 8

Serotonin, and is only broken MAO

Question 9

What are the rule for determining if a substance is a neurotransmitter?

Answer 9

1. Present in presynaptic vesicles
2. Must occur naturally within system
3. Must be released when an action potential invades the terminal.
4. produce a PSP when applied
5. Should have specific receptor in post synaptic membrane
6. reception should lead to change in membrane potential of dendritic spine
7. some specific mechanism should exist for inactivation of substance once released
8. sam effect for stimulating nerve and releasing chemical on dendritic spine.

Question 10

What are amino acid neurotransmitters?

Answer 10

simple molecules and do not need a synthesis pathway

Question 11

What are the 2 amino acid neurotransmitters?

Answer 11

Glutamate & GABA

Question 12

Glutamate

Answer 12

• is a very common chemical in the brain
• it is produced in the Krebs cycle
• all cells have glutamate
• it is excitatory
• crucial in the process of long term potentiation

Question 13

What are the 3 types of iontropic glutamate receptors?

Answer 13

AMPA
NMDA
Kainate

Question 14

AMPA

Answer 14

• responds strongly to the drug
• has a sodium channel
• generates an EPSP

Question 15

Kainate

Answer 15

• has a sodium channel
• responds to a neurotoxin called kainic acid that is obtained from sea weed.

Question 16

NMDA

Answer 16

• has a calcium channel
• is crucial in LTP
• NMDA receptor is blocked at RP by magnesium ion

Question 17

Acetylcholine

Answer 17

• is found in skeletal muscle synapses
• is the most common excitatory neurotransmitter in the PNS
• heavily involved in Alzheimer’s disease

Question 18

What are the two types of receptors for ACh?

Answer 18

Nicotine (PNS) & Muscarine (CNS)

Question 19

Explain what the torpedo fish does?

Answer 19

• the torpedo fish generated electric shocks to stun prey and deter predators

Question 20

What are monoamine neurotransmitters?

Answer 20

• are constructed from single amino acids and are broken down by monoamine oxidase

Question 21

What is tyrosine?

Answer 21

is the precursor amino acid of catecholamines

Question 22

what is tryptophan?

Answer 22

is the precursor amino acid of indoleamines

Question 23

What is the breakdown enzyme that breaks down Tyrosine into DOPA?

Answer 23

Tyrosine Hydroxylase (TH)

Question 24

What is the breakdown enzymes that breaks down DOPA into Dopamine?

Answer 24

Dopa Decarboxylase

Question 25

What is Dopamine?

Answer 25

- has a dopaminergic synapse - dopamine is inhibitory at most CNS synapses - involved in Parkinson's disease.

Question 26

Are D1 dopamine receptors excitatory or inhibitory? and why?

Answer 26

are excitatory because they increase cAMP at the dendritic spine. Increasing cAMP means more sodium channels are open, depolarizing the membrane.

Question 27

Are D2 dopamine receptors excitatory or inhibitory? and why?

Answer 27

are inhibitory because they decrease cAMP levels.

Question 28

The pathway between the ventral tegmental area and the nucleus accumbens is what?

Answer 28

dopaminergic

Question 29

What is the breakdown enzyme that breaks down dopamine to norepinephrine?

Answer 29

DBH

Question 30

What is the breakdown enzyme for Serotonin?

Answer 30

MAO

Question 31

Serotonin

Answer 31

Is the neurotransmitter that is released by the raphe nucleus

Question 32

Where does is LSD obtained from?

Answer 32

From ergot - wheat or rye when it is damp and warm

Question 33

What are the natural ligands in the brain?

Answer 33

Enkephalins

Question 34

What are the 2 classes of endogenous opiate receptors that enkephalins activate?

Answer 34

Mu and Delta

Question 35

Mu receptors

Answer 35

are the most general and are activated by endorphins and enkephalins but have the highest affinity for opiate drugs

Question 36

Delta receptors

Answer 36

are only activated by enkephalins and opiate drugs.

Question 37

What plays a major role in transmission of pain signals to the brain?

Answer 37

Substance P

Question 38

What is the foundation molecule of ATP?

Answer 38

Adenosine

Question 39

What does naloxone do?

Answer 39

It treats overdoses by knocking the opiate off the receptor

Question 40

What does nitric oxide do?

Answer 40

- it is a messenger in many parts of the body - one main function may be involved in long term potentiation - functions as a retrograde messenger

Question 41

Where are hormones released from?

Answer 41

secretory cells

Question 42

What is the master endocrine gland in the body?

Answer 42

the pituitary gland

Question 43

Explain how steroid hormones interact with the cell?

Answer 43

- enter cells and activate genes in the nucleus - steroid hormones bond inside the cell - water soluble hormones bind outside the cell

Question 44

alpha receptors inhibit what?

Answer 44

adenylate cyclase to reduce second messenger levels

Question 45

Beta Receptors activate what?

Answer 45

adenylate cycle to increase second messenger levels.