04a: NT and Neuromodulators Flashcards Preview

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Flashcards in 04a: NT and Neuromodulators Deck (50):
1

List the three main types of signal transduction pathways in plasma membrane receptors.

1. Ligand-gated channel (ionotropic)
2. G-Protein with second messenger production
3. G-protein with control of ion channel

2

G-Proteins can couple receptor to:

1. Ion channel
2. Effector protein

3

G(s) is activated. What's its immediate effect?

Activates adenylyl cyclase

4

Adenylyl cyclase is activated by which specific G-protein? What's AC's function?

G(s);
Produces cAMP (second messenger) from ATP

5

cAMP action is terminated by (X).

X = hydrolysis via PDE

6

G(c) is activated. What's its immediate effect?

Activates guanylyl cyclase

7

Guanylyl cyclase is activated by which specific G-protein? What's GC's function?

G(c);
Produces cGMP

8

G(i) is activated. What's its immediate effect?

Inhibits adenylyl cyclase

9

G(q) is activated. What's its immediate effect?

Activates PLC

10

PLC is activated by which specific G-protein? What's PLC's function?

G(q);
Produces second messengers (IP3 and DAG)

11

Odorants activate (X), which causes (increase/decrease) in (Y), which causes (increase/decrease) in (Z). Hence, (de/re/hyper)-polarization of olfactory receptors.

X = G(olf) G-protein
Increase;
Y = cAMP concentration;
Increase;
Z = permeability to Na and Ca
Depolarization

12

List mechanisms that cause cessation of activity caused by G-proteins.

1. 2nd messengers inactivated
2. Phosphorylation/altering of receptors (less affinity for ligand)
3. Receptor-NT complexes removed via endocytosis

13

List the biogenic amines.

1. NE
2. Serotonin
3. DA
4. Histamine

14

List two examples of catecholamines.

NE and DA

15

Enkephalin falls into which NT category? Name another NT that belongs in this category,

Neuroactive (Opioid) peptides

Endorphins

16

List some gases that act as NT.

NO and CO

17

List purines that act as NT.

ATP and adenosine

18

Somatic NS uses (X) NT receptor. Its activation causes

X = nicotinic ACh

Increase in gNa, gK, gCa (depolarization)

19

Binding of (X) to D1 receptors causes (increase/decrease) in which ion/messenger?

X = DA;

Increase in cAMP through G(s)

20

Binding of (X) to D2 receptors causes (increase/decrease) in which ion/messenger?

X = DA

Decrease in cAMP through G(i)

21

Which NT is considered the messenger for pleasure and reward?

DA

22

Cocaine (stimulates/inhibits) the reuptake of (X), thus reinforcing its action.

Inhibits;
X = DA

23

Glutamate reacts with (metabotropic/ionotropic) receptors

Both

24

List the receptor subtypes that act as ion channels activated by glutamate.

1. Kainate
2. AMPA
3. NMDA

25

NMDA channel is (blocked/unblocked) at Vm and is (blocked/unblocked) at (X) mV. By what?

Blocked; Unblocked
X = -60 (or more positive)

Mg

26

T/F: A signal that opens AMPA channel will always open NMDA channel.

False - NMDA also voltage-dependent

27

GABA is formed from (X).

X = Glutamate

28

List GABA receptors. Star the ones that are metabotropic

GABA(a) and GABA(b)*

29

Activation of GABA(a) receptor causes (increase/decrease) in

Increase;
gCl (opposes depol)

30

Activation of GABA(b) receptor causes (increase/decrease) in

Decreases gCa and increases gK (via Gi)

31

Glycine primarily acts by (increasing/decreasing) (X) conductance in (brain/SC).

Increasing;
X = Cl
SC

32

List examples of NTs in the class of neuroactive peptides.

1. ADH and oxytocin
2. CCK and VIP
3. Substance P
4. Opioid peptides

33

T/F: Only neurons release NO.

False - endothelial cells too

34

NO mechanism is to (increase/decrease) (extracellular/cytosolic) which ion/second messenger?

Increase;
cytosolic;
cGMP

35

ATP and adenosine act as (stimulatory/inhibitory) transmitters in autonomic NS.

Inhibitory

36

ATP and adenosine act on (G-protein/ligand-gated) receptors.

Both

37

In G-proteins, the alpha subunit is bound to (receptor/beta-gamma/GDP/GTP) when interacting with effector proteins.

Bound to GTP

38

In G-proteins, which component is a GTPase? What occurs when it hydrolyzes GTP?

alpha subunit;
converts it back to inactive state (GDP-bound)

39

Which ACh receptors are found in abundance in CNS? They use the (X) messenger system - causing increase/decrease in conductance of which ion(s)?

M1 metabotropic receptors;
X = IP3

Increase gCa and decrease gK

40

Serotonin is produced from (X) and broken down by (Y).

X = tryptophan;
Y = oxidization by MAO

41

Hallucinogenic agents, such as (X), are (Y) (agonists/antagonists).

X = LSD;
Y = serotonin;
Agonists

42

Serotonin binds to (X) receptors. All are (ionotropic/metabotropic).

X = 5-HT

Most metabotropic (GPCRs) except one

43

Histamine receptors are found in which location(s)?

Peripheral tissues and brain

44

Glu and Asp serve as NT at vast majority of (inhibitory/excitatory) synapses in (CNS/PNS).

Excitatory; CNS

45

Main excitatory NT in brain.

Glu

46

Glu (metabotropic/ionotropic) receptors involved in synaptic plasticity.

Metabotropic

47

Main inhibitory NT in brain.

GABA

48

GABA is formed from:

Glutamate

49

Barbiturates/benzos are meds for (X). What's the Mechanism?

X = reducing anxiety/relaxing muscles

Enhance GABA(a) effect on gCl

50

Blocking of Glycine receptors by (X) causes (Y).

X = strychnine
Y = hyperactivity/convulsions