Medchem Lecture 13

Front 1

Neurotransmission in the CNS occurs mostly with these three amino acids:

Back 1

1. γ-aminobutyric acid (GABA), 2. glutamic acid (glutamate [Glu]) and
3. glycine

Front 2

What % of all neurons in the CNS use GABA as a neurotransmitter substance?

Back 2

40%

Front 3

Less than 10% of neurons use one of the other monoamine types which are:

Back 3

NE, serotonin, and acetylcholine

Front 4

Amino acid neurotransmitters are subcategorized into

Back 4

excitatory and inhibitory

Front 5

Four excitatory amino acid neurotransmitters

Back 5

1. glutamate (Glu)
2. aspartate (Asp)
3. cysteine
4. homocysteine

Front 6

Four inhibitory amino acid neurotransmitters

Back 6

1. GABA
2. glycine (Gly)
3. taurine
4. β-Alanine

Front 7

When neuronal cells are at rest, are the ion channels opened or closed?

Back 7

closed

Front 8

When a neuron is depolarized, what ion types are entering the cell through channels?

Back 8

Na+ and Ca2+

Front 9

When the neuron is _________, the membrane potential is more positive and in turn more likely to exhibit an action potential causing an electrical current to flow to other points in the membrane

Back 9

depolarized

Front 10

When a neuron is __________, K+ moves out of the cell into extracellular space or Cl- moves into the cell

Back 10

hyperpolarized

Front 11

Ion fluxes of K+ or Cl- results in this, which decreases the likelihood that a neuronal cell will fire

Back 11

hyperpolarization

Front 12

Excitatory membrane potential is also known as

Back 12

depolarization

Front 13

Inhibitory membrane potential is also known as

Back 13

hyperpolarization

Front 14

The two nonresting states of neuronal cells:

Back 14

excitatory and inhibitory

Front 15

During this nonresting state, Na+ or Ca2+ ions move into the cell, making the membrane potential grow until action potential is reached

Back 15

excitatory

Front 16

During this nonresting state, Cl- moves into the cell or K+ moves out of the cell, causing the neuron to return to resting state

Back 16

inhibitory

Front 17

The major EEA (excitatory amino acid) neurotransmitter in the CNS is ________, which is found in all cells in the CNS

Back 17

L-glutamate

Front 18

This EEA is a precursor in the biosynthesis of inhibitory neurotransmitter GABA

Back 18

glutamate

Front 19

The receptors for glutamate and other EEAs are categorized into two major groups

Back 19

ionotropic and metabotropic

Front 20

These EEA receptors are associated with ligand-gated ion channels

Back 20

ionotropic

Front 21

The three ionotropic receptor types are classified based on their ________ _________ for the EAA ligands

Back 21

selective affinity

Front 22

1. N-methyl-D-aspartate (NMDA)
2. α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and
3. kainite

Back 22

ionotropic receptor types

Front 23

This is a homologue of the neurotoxin ibotenic acid found in Amanita mushrooms

Back 23

AMPA, ionotropic receptor

Front 24

This is a neurotoxin isolated from red algae

Back 24

Kainate, ionotropic receptor

Front 25

This EAA ionotropic receptor subtype increases Na+ and Ca2+ INFLUX and increases K+ EFFLUX

Back 25

AMPA

Front 26

This EAA ionotropic receptor subtype increases Na+ INFLUX and increases K+ EFFLUX

Back 26

kainate

Front 27

This EAA ionotropic receptor subtype increases Ca2+ INfLUX and increases K+ EFFLUX and glycine

Back 27

NMDA

Front 28

Is glutamate an agonist or antagonist for each of the EAA ionotropic receptor subtypes?

Back 28

Agonist

Front 29

Activation of EAA metabotropic receptors results in alterations in these processes within the cell

Back 29

metabolic processes

Front 30

All of these EAA receptors are activated by glutamate and ibotenate

Back 30

metabotropic receptors

Front 31

Are any of the metabotropic receptors activated by NMDA, AMPA or kainate?

Back 31

None of them are activated

Front 32

The major inhibitory amino acid (IAA) neurotransmitter in the mammalian CNS is

Back 32

γ-Aminobutyric Acid (GABA)

Front 33

How many different families of GABA receptors are identified

Back 33

three, A,B,C

Front 34

This IAA receptor was the first to be identified and is a ligand-gated ion channel

Back 34

GABA

Front 35

What major class of compound modulates GABAa receptor function?

Back 35

benzodiazepines (e.g. diazepam)

Front 36

The second most common inhibitory amino acid neurotransmitter in the CNS

Back 36

glycine

Front 37

Agents that act as agonists at this IAA receptor may be anticonvulsants, muscle relaxants, sedatives and general anesthetics

Back 37

glycine receptor

Front 38

The best described ANTAGONIST of the inhibitory glycine receptor is this convulsant

Back 38

styrchnine

Front 39

The inhibitory glycine receptor is sometimes referred to as this in order to distinguish it from a glycine site on the NMDA receptor

Back 39

strychnine-sensitive glycine receptor

Front 40

This agent has also been shown to antagonize the activity of glycine at its receptor (NOT strychnine)

Back 40

anandamide

Front 41

These reversibly block the nerve conductances that transmit the feeling of pain to the brain

Back 41

local anesthetics

Front 42

Do general and local anesthetic drugs block nerve conductance in both sensory and motor neurons or just one of them?

Back 42

both sensory and motor

Front 43

Do general anesthetics cause loss of consciousness or impairment of vital functions?

Back 43

NO

Front 44

Are coca leaves (cocaine) known to have local or general anesthetic properties?

Back 44

local

Front 45

Benzoylatropine is the same chemical structure as cocaine but is missing which functional group?

Back 45

ester functional group

Front 46

Benzoylatropine led to the discovery of which other drug

Back 46

procaine

Front 47

Is cocaine a vasodilator or vasoconstrictor?

Back 47

vasoconstrictor

Front 48

All procaine-derived local anesthetics are associated with what property

Back 48

vasodilation

Front 49

In order to decrease the rate of removal of procaine-derived local anesthetics from the site of administration, a vasoconstrictor like this is commonly used

Back 49

epinephrine

Front 50

This local anesthetic is most widely used

Back 50

lidocaine

Front 51

These two cyclic nucleotides play critical roles in mediating cellular signals in response to hormones, neurotransmitters, chemokines and cytokines

Back 51

cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP)

Front 52

These hydrolyze the cyclic nucleotides to their inactive linear forms (5'-AMP and 5'-GMP)

Back 52

phosphodiesterases (PDEs)

Front 53

Vardenafil (Levitra), Sildenafil (Viagra) and Tadalafil (Cialis) are all developed for the Tx of male erectile dysfunction

Back 53

selective PDE5 inhibitors