Cellular communication 5

Question 1

The NMDA receptor has binding sites for: (select 3)
a. gamma-aminobutyric acid
b. glutamate
c. propofol
d. ketamine
e. magnesium
f. calcium

Answer 1

b. glutamate
d. ketamine
e. magnesium

Question 2

The amino acid neurotransmitters include:

Answer 2

glutamate
GABA
glycine

Question 3

__________________ is the primary excitatory neurotransmitter in the brain

Answer 3

Glutamate

Question 4

______________ is the main inhibitory neurotransmitter in the brain

Answer 4

GABA

Question 5

_____________________ is the primary inhibitory neurotransmitter in the spinal cord and lower brainstem

Answer 5

Glycine

Question 6

Glutamate and GABA are interconvertible through

Answer 6

Krebs cycle intermediates

Question 7

Glutamate receptors can be

Answer 7

ionotropic or metabotropic

Question 8

NMDA and AMPA receptors are ___________ receptors

Answer 8

ionotropic glutamate

Question 9

Neuronal injury initiated by excessive glutamate receptor activity is called

Answer 9

excitotoxicity

Question 10

The glycine receptor is

Answer 10

ionotropic

Question 11

GABA receptors can be

Answer 11

ionotropic or metabotropic

Question 12

In a glial cell, glutamate is converted into

Answer 12

glutamine by the enzyme glutamine synthetase

Question 13

The three types of ionotropic glutamate receptors are named for

Answer 13

the pharmacologic agents that activate them

Question 14

The three types of ionotropic glutamate receptors are:

Answer 14

1. NMDA
2. Kainate receptors
3. a-amino3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors

Question 15

Full activation of AMPA receptors requires the binding of

Answer 15

two glutamate molecules

Question 16

AMPA receptors have ________________ synaptic transmission

Answer 16

fast-gating (rapid) excitatory

Question 17

AMPA receptors are highly permeable to _________ and poorly permeable to

Answer 17

Na+; Ca2+

Question 18

Full activation of NMDA receptors requires the binding of

Answer 18

two glutamates
two glycine molecules
a depolarizing voltage change

Question 19

NMDA receptors are highly permeable to ______________ and poorly permeable to ________

Answer 19

Ca2+; Na+

Question 20

NMDA receptors have ________ synaptic transmission

Answer 20

slower-gating (delayed)

Question 21

Metabotropic glutamate receptors are classified into three groups:

Answer 21

group 1 receptors are couple to Gq- they activate phospholipase C
group 2 & 3 receptors are couple to Gi- they prevent the formation of cAMP

Question 22

Increased released or decreased uptake of glutamate can lead to a positive feedback cycle involving increased

Answer 22

intracellular Ca2+, cellular damage and further glutamate release

Question 23

Too much of a good thing (intracellular Ca2+) leads to

Answer 23

neuronal injury or neuronal death by apoptosis

Question 24

Neuronal injury initiated by excessive glutamate receptor activity is called

Answer 24

excitotoxicity

Question 25

Excitotoxicity is implicated as a pathologic mechanism in many diseases including

Answer 25

Huntington's disease Alzheimer's disease ALS stroke & trauma hyperalgesia epilepsy

Question 26

The amount of GABA in the CNS correlates to the amount of

Answer 26

functional GAD (glutamic acid decarboxylase- which catalyzes glutamate to GABA)

Question 27

How is glycine formed?

Answer 27

glycolysis--> serine--> glycine

Question 28

Glycine is taken up from the synaptic cleft by

Answer 28

neurons through a glycine transporter

Question 29

Mutations of the glycine receptor are involved in a rare neurological disease

Answer 29

human startle disease or hyperekplexia

Question 30

Human startle disease is characterized by

Answer 30

temporary muscle rigidity in response to unexpected stimuli

Question 31

At resting membrane potential, magnesium channels block _____________ receptors.

Answer 31

NMDA

Question 32

What two binding sites are located in the NMDA receptor channel (pore)?

Answer 32

Mg2+ ketamine/PCP

Question 33

Which GABA receptor is metabotropic?

Answer 33

GABAb

Question 34

Glutamate is converted to GABA by what type of enzymatic reaction?

Answer 34

decarboxylation

Question 35

Which enzymes are required to degrade epinephrine to vanillymandelic acid? (select 2) a. catechol-O-methyltransferase b. L-amino acid decarboxylase c. monamine oxidase d. tyrosine hydroxylase

Answer 35

a. catechol-O-methyltransferase c. monamine oxidase

Question 36

What are the five biogenic amine neurotransmitters?

Answer 36

dopamine norepinephrine epinephrine serotonin histamine

Question 37

Dopamine, norepinephrine, and epinephrine are collectively known as

Answer 37

catecholamines

Question 38

All biogenic amine neurotransmitters are derived from __________ by ________________ & ____________________

Answer 38

amino acids; hydroxylation & decarboxylation (there is an exception)

Question 39

The rate-limiting step in catecholamine biosynthesis is

Answer 39

tyrosine hydroxylase

Question 40

Degradation of NE & epi is carried out by two enzymes:

Answer 40

monoamine oxidase catechol-O-methyltransferase

Question 41

The end-product of catecholamine metabolism is

Answer 41

vanillymandelic acid

Question 42

Serotonin is syntheized from

Answer 42

tryptophan

Question 43

Histamine is synthesized from

Answer 43

histidine

Question 44

___________________ is the end-product of serotonin metabolism.

Answer 44

5-hydroxyindoleacetic acid

Question 45

The biogenic amines elicit a wide range of physiologic responses in the periphery and in the CNS including:

Answer 45

central control of cardiac function, BP, and metabolism coordination of movement cognitive function regulation of appetite & feeding sleep behavior

Question 46

The exception of biogenic amine transmitter receptors being metabotropic receptors is the

Answer 46

ionotropic 5-HT3 serotonin receptor

Question 47

What two enzymatic reactions are common in the biosynthesis of biogenic amine neurotransmitters?

Answer 47

hydroxylation decarboxylation

Question 48

What is hydroxylation?

Answer 48

add an -OH group

Question 49

What is decarboxylation?

Answer 49

removes a CO2 group

Question 50

MAO-A preferentially degrades

Answer 50

dopamine, epinephrine, and serotonin

Question 51

MAO-B degrades

Answer 51

dopamine more rapidly than serotonin and norepinephrine

Question 52

The most common screening test used to establish the diagnosis of pheochromocytoma is:

Answer 52

catecholamine metabolites in the urine

Question 53

Dopamine is metabolized by

Answer 53

both MAO & COMT

Question 54

The major metabolite of dopamine is

Answer 54

homovanillic acid (HVA)

Question 55

High levels of 5-HIAA in the urine are consistent with

Answer 55

carcinoid tumors