Lecture 12: Neurotransmitters Part I

Question 1

Chemical signaling consists of what 3 parts?

Answer 1

signal
receptor
target molecule/ion channel

Question 2

Ionotropic receptors are ___________ channels and the _________ is the channel

Answer 2

ligand gated, receptor

Question 3

Metabotropic receptors contain __________ receptors and the receptor _________ channel.

Answer 3

g-protein coupled, modulates

Question 4

In Ionotropic receptors, the _______________ forms the ion channel,

Answer 4

Membrane spanning region

comprised of 4-5 subunits

Question 5

What are the ionotropic glutamate receptors?

Answer 5

NMDA, AMPA/Kainate

Question 6

Name the cys-loop receptors

Answer 6

nAChR, 5-HT3, GabaA, Glycine, purinergic

Question 7

Ionotropic receptors contain __ subunits and a complete receptor of _______ subunits

Answer 7

1, 4 or 5

Question 8

Name 3 main features of the metabotropic receptors.

Answer 8

g protein coupled receptors are here
Monomeric proteins consisting of 7 transmembrane domains
Domains 2,3,6,7 make up NT binding region

Question 9

nACh receptor is an __________ receptor

Answer 9

ionotropic

Question 10

nAChR consists of ____ subunits, and its alpha subunits bind _________.

Answer 10

5, ACh

Question 11

In nAChR, each subunit has 4 __________. The M2 subunit line ______.

Answer 11

transmembrane spanning a-helices, pore

Question 12

The cytoplasm side of the nAChR receptor has rings of high negative charge that determine the _____________ of the receptor and remove the ___________ of the passing ions.

Answer 12

cation specificity, hydration shell

Question 13

nAChR is a _________ cation channel

Answer 13

non-selective

Question 14

Higher driving force for Na+ results in and inward current and an _______.

Answer 14

EPSP

Question 15

What are the precursors for ACh

Answer 15

acetyl coenzyme A and choline

Question 16

_______ catalyzes acetylcholine.

Answer 16

ChAT (choline acetyltransferase)

Question 17

__________ breaks up ACh into acetate and choline

Answer 17

AChE

Question 18

What takes choline backs up into the presynaptic terminal?

Answer 18

Na+/choline transporter

Question 19

What condition is characterized by a decrease in EPP?

Answer 19

Myasthenia Gravis

Question 20

What treats myasthenia gravis?

Answer 20

reversible AChE inhibitors

Question 21

What causes myasthenia gravis?

Answer 21

antibodies that block AChRs at the post-synaptic NMJ

Question 22

Insecticides and nerve gases are examples of ____________

Answer 22

Irreversible AChE inhibitors

completely inhibit ACh breakdown

Question 23

Nerve gases and insecticides cause _________ and _________, particularly resulting in muscle/respiratory failure

Answer 23

overstimulation, neuromuscular paralysis

Question 24

Classification based on sensitivity for plant alkaloids from tobacco plant and poisonous red mushroom.

Answer 24

Nicotinic and muscarinic AChRs

Question 25

Give an example of nicotinic agonist.

Answer 25

betel nuts

Question 26

Give some examples of muscarinic antagonists.

Answer 26

nightshade, belladonna, scopolamine

Question 27

Muscarinic receptors are _________.

Answer 27

GPCRs

Question 28

What's the precursor of glutamate and who releases it?

Answer 28

glutamine, released by glia

Question 29

Enzyme ________ catalyzes glutamate from glutamine

Answer 29

glutaminase

Question 30

VgluT is the _______ transporter

Answer 30

glutamate

Question 31

What is the EAAT?

Answer 31

excitatory amino acid transporter

Question 32

NMDA-R serves as a ________ detector

Answer 32

coincidence

Question 33

T/F: voltage-dependent block by Mg2+ ion needs to be relieved by depolarization

Answer 33

True

Question 34

T/F: Influx of Ca2+ acts as first messenger at intracellular signaling pathways

Answer 34

false, acts as second messenger, relevant to plasticity

Question 35

T/F: Ca2+ influx through NMDA-Rs results in AMPA-R phosphorylation (early phase) and eventually gene transcription and protein synthesis (late phase).

Answer 35

True

Question 36

What's excitatory, Gq-coupled (PLC  ion channels; increase NMDA) - mostly postsynaptic

Answer 36

Group I, mGLuRs 1 and 5

Question 37

What's inhibitory, Gi/Go- coupled ( reduce cAMP), decrease transmitter release; decrease NMDA - mostly presynaptic, and on glia cells

Answer 37

Group II, mGLuRs 2 and 3

Question 38

What's inhibitory, Gi/Go- coupled ( reduce cAMP), decrease transmitter release; decrease NMDA - mostly presynaptic

Answer 38

Group III, mGLuRs 4,6,7,8

Question 39

GLutamate decarboxylase catalyzes _______ to _______

Answer 39

glutamate, GABA

Question 40

What does VIATT stand for?

Answer 40

vesicular inhibitory amino acid transporter

Question 41

What is the GABA transporter that removes it from synaptic cleft?

Answer 41

GAT

Question 42

The ionotropic GABA receptors are?

Answer 42

GABAa and GABAc

Question 43

Effects of GABA agonists?

Answer 43

anxiolytic anesthetic sedative anti-convulsive

Question 44

Both benzodiazepines and barbiturates (or alcohol) facilitate the ability of GABA to activate the receptor and opening of the _________.

Answer 44

``` chloride channel (Barbituates increase length of opening, benzodiazepines increase frequency) ```

Question 45

What reduces probability of firing of an action potential?

Answer 45

Synaptic inhibition

Question 46

_____________ open chloride channels, which results in inward flow of negatively charged Cl- ions which causes hyperpolarization.

Answer 46

GABAa/glycine receptors

Question 47

As long as the ECl- is more hyperpolarized (negative) than the action potential threshold, what can happen?

Answer 47

Depolarizing synaptic potentials can inhibit neurons.

Question 48

In ________ neurons the intracellular Cl- concentration is controlled by _________, yielding high intracellular level of Cl-

Answer 48

developing, Na/K/Cl co transporter

Question 49

In _______ cells a ______ co transporter pumps Cl out and lowers internal Cl, making ECl- much more negative

Answer 49

adult, K/Cl

Question 50

What stimulates opening of K+ channels?

Answer 50

Metabotropic GABA receptors (GABAb), inhibits Ca2+ channels

Question 51

2 major subtypes of metabotropic GABA receptors are BR1 and BR2, and can assemble as homodimers or __________

Answer 51

heterodimers

Question 52

Activation of _________ GABAb __________ can inhibit release of GABA from the terminal.

Answer 52

presynaptic, autoreceptors

Question 53

What can also inhibit release of dopamine, norepinephrine and serotonin?

Answer 53

presynaptic GABAb

Question 54

What system is a major target for glial modulators?

Answer 54

GABAergic systems