Test 2: Indolamines/Acetylcholine

Question 1

5HT synthesis starts with the amino acid ____

Answer 1

tryptophan

Question 2

Determines the rate of synthesis

Answer 2

rate limiting step

Question 3

An irreversible inhibitor of 5HT

Answer 3

para-chlorophenylaline (PCPA)

Question 4

What is the rate limiting step in 5HT production?

Answer 4

tryptophan hydroxylase converting tryptophan to 5HTP

Question 5

___ packages 5HT into classical synaptic vesicles, provides means for releasing predetermined amount

Answer 5

vesicular monoamine transporter (VMAT)

Question 6

5HT is released primarily by __ dependent mechanisms

Answer 6

Ca

Question 7

5HT is [excited/inhibited] by auto-receptors on the synaptic terminal surface, dendrites, or somata

Answer 7

inhibited

Question 8

5HT is inactivated by 2 different responses: __ and __

Answer 8

reuptake and metabolism

Question 9

5HT is metabolized by __, creating __

Answer 9

monoamine oxidase (MAO); 5-hydroxindolacetic acid (5HIAA)

Question 10

Network of 5HT cell groups projecting to the forebrain, midbrain, cerebellum, cord

Answer 10

B cell groups

Question 11

all 5HT receptors are [metabotropic/ionotropic] with the exception of 1 subtype

Answer 11

metabotropic

Question 12

The only excitatory ionotropic 5HT receptor subtype

Answer 12

5HT3

Question 13

For the most part, 5HT is [excitatory/inhibitory]

Answer 13

inhibitory

Question 14

What kind of 5HT receptors are concentrated in the hippocampus, septum, amygdala, and raphe?

Answer 14

5HT1A

Question 15

5HT binding to 5HT1A receptors functions by two major mechanisms: ___, which inhibit adenylate cyclase and cAMP production, and __ channel opening, producing hyperpolarization

Answer 15

Gi coupled receptors; K+

Question 16

What receptor subtype do anxiety meds and appetite/alcohol drive suppressant

Answer 16

5HT1A

Question 17

Which 5HT receptor subtype are concentrated in cortex, striatum, and nucleus accumbens?

Answer 17

5HT2A

Question 18

__ receptor subtype function is implicated in sensory perception and integration (thalamus)

Answer 18

5HT2A

Question 19

5HT binds to 5HT2A by activating PI 2nd messenger systems which have two major consequences: __ and __

Answer 19

activates protein kinase C, increases release of cellular stores of Ca

Question 20

5HT2A’s release of cellular stores of Ca may also reduce __ channel opening, which produces depolarization and therefore is __

Answer 20

K+, excitatory

Question 21

Hallucinogenic drugs act as __ on __ receptors

Answer 21

agonists, 5HT2A

Question 22

Ach is synthesized from two precursors: __ and __

Answer 22

choline and acetyl coenzyme A (acetyl CoA)

Question 23

Ach’s rate limiting step is synthesis by __

Answer 23

choline acetyltransferase (ChAT)

Question 24

The stimulation of ChAT is a [positive/negative] feedback mechanism

Answer 24

positive

Question 25

Ach is packaged into small classic synaptic vesicles and ___ provides means for releasing predetermined amount

Answer 25

vesicular Ach transporter (VAchT)

Question 26

Ach is released by __ dependent mechanisms (pre-synaptic potential)

Answer 26

Ca++

Question 27

Animal and bacterial toxins influence __ release (ex: black widow venom)

Answer 27

Ach

Question 28

Ach is metabolized by __ in the presynaptic terminal and on postsynaptic membranes

Answer 28

acetylcholinesterase

Question 29

When Ach is metabolized, it becomes __ and __

Answer 29

choline and acetic acid

Question 30

Ach uses __ for reuptake, which shuttles __ from synapse back to terminal (necessary for rapid removal of precursor from synapse)

Answer 30

choline transporter; choline

Question 31

Ach reuptake is blocked by the drug ___

Answer 31

hemicholinium-3 (HC-3)

Question 32

___ Ach cells innervate many brain sites

Answer 32

projecting

Question 33

the two main subtypes of Ach receptors

Answer 33

muscarinic and nicotinic

Question 34

Ach receptor subtype found on muscles, ganglia (PNS) and certain CNS regions

Answer 34

nicotinic

Question 35

nicotonic Ach receptors are [metabotropic/ionotropic]

Answer 35

ionotropic

Question 36

nicotinic Ach receptors are [stimulatory/inhibitory]: ion channel for __ and __

Answer 36

stimulatory; Na and Ca

Question 37

continuous agonist exposure on nicotonic Ach receptors causes __

Answer 37

desensitization

Question 38

Is desensitization of nAch receptors reversible?

Answer 38

Yes

Question 39

because of persistent depolarization, a cell cannot become active until an agonist is removed and the membrane is repolarized

Answer 39

depolarization blockade

Question 40

__ Ach receptors are widely distributed in the CNS (cortex, hippocampus, thalamus, striatum, basal forebrain)

Answer 40

muscarinic

Question 41

__ Ach receptor function is important in CNS for cognition (cortex and hippocampus), motor behavior (striatum), and drug reward (basal forebrain)

Answer 41

muscarinic

Question 42

In the PNS, __ Ach receptors are ocated in heart, visceral smooth muscle, bronchioles, and secretory organs

Answer 42

muscarinic