Drugs Relating to Electrophysiology

Question 1

GLU

Answer 1

Aka Glutamate
(excitatory neurotransmitter)

Binds to NMDA receptor (mixed Na+/Ca++ channel) to depolarize (easier for AP to occur)

Question 2

GABA

Answer 2

Inhibitory neurotransmitter

Binds to GABAa receptor (Cl- channel) to hyperpolarize/resist depolarization (harder for AP to occur)

Question 3

Phenobarbital

Answer 3

Increases activation of GABAa RECEPTOR (inhibits neuron firing bc there is an increase in inhibitory neurotransmitters)

Question 4

Diazepam

Answer 4

Increases activation of GABAa RECEPTOR (inhibits neuron firing bc there is an increase in inhibitory neurotransmitters)

Question 5

Tiagabine

Answer 5

Inhibits GAT-1 –> inhibits GABA uptake (TRANSPORTER) which increases [GABA] in cleft

Question 6

Vigabatrin

Answer 6

Inhibits GABA-T –> decreases GABA breakdown (ENZYME) which increases [GABA] available to be released into cleft

Question 7

Felbamate

Answer 7

Inhibits NMDA RECEPTOR (decreases excitatory due to less uptake of GLU)

Question 8

Gabapentin

Answer 8

Increases GABA release + Decreases GLU release (NEUROTRANSMITTERS)

Question 9

Phenytoin

Answer 9

Prolongs Na+ channel inactivation –> increases refractory period –> resists depolarization (ION CHANNEL)

Question 10

Carbamazepine

Answer 10

Prolongs Na+ channel inactivation –> increases refractory period –> resists depolarization (ION CHANNEL)

Question 11

Ethosuximide

Answer 11

Inhibits Ca++ channels (ION CHANNEL)

Question 12

Permethrin

Answer 12

General: holds Na+ channels open (causing depolarization)

Low Dose: some Na+ channels open (like leak channels) –> Vm slowly depolarizes towards thresholds (causing uncontrolled APs)

High Dose: Depolarization Blockage = Na+ channels open and cause large depolarization + can’t repolarize

Question 13

Lidocaine

Answer 13

General: Na+ channel blocker

Low Dose: prolongs inactivation of Na+ channels (decreases firing AP)

High Dose: blocks opened Na+ channels (prevents APs)