GABA + Glutamate

Question 1

Glutamate Receptors

Answer 1

Ionotropic (excitatory, 3 types)
-excitatory ONLY
Metabotropic (GCPR, 8 subtypes)
-excitatory, inhibitory, modulatory

Question 2

Ion Channel Receptors (3)

Answer 2

1. ) AMPA (Na/K)
2. ) Kainate (Na/K)
3. ) NMDA (Na/K + Ca)*****

Question 3

NMDA Receptor: Glutamate

Answer 3

• primary neurotransmitter at NMDA receptors

- binds extracellularly

Question 4

NMDA Receptor: Glycine

Answer 4

• binds extracellularly

- glutamate activity requires bound glycine

Question 5

NMDA Receptor: PCP

Answer 5

Phenylcyclidine (STREET DRUG)

-binds receptor within channel (blocking)

Question 6

NMDA Receptor: Zn Ion

Answer 6

• binds within ion channel
• blocks depolarization/channel @ rest
• move off during depolarization

Question 7

Drugs that bind PCP Site (3)

Answer 7

1. ) PCP (phencyclidine)
2. ) Ketamine
3. ) Dextromethorphan
   - weak affinity but can be bound at high dose

Question 8

Low-affinity, non-competitive NMDA Antagonists (2)

Answer 8

Bind PCP site with low affinity (low side-effects)

1. ) Amantadine
   - Parkinson’s disease treatment
2. ) Memantine***
   - Alzheimer’s disease treatment

Question 9

Felbamate

Answer 9

Anti-seizure medication

-binds NMDA receptor @ unknown site

Question 10

Glutamate INHIBITORs

Answer 10

Sodium Channel Blockers: Phenytoin, carbamazepine

Calcium Channel Blockers; Lamotrigine, gabapentin

Question 11

Glutamate BLOCKERs

Answer 11

NMDA Receptors: Felbamate, memantine, amantidine

AMPA Receptors: Topiramate, perampanel

Question 12

GABA Synthesis

Answer 12

Glutamine –> Glutamate –> GABA

1. ) Glutaminase
2. ) GAD (glutamic acid decarboxylase)

Question 13

GABA-A: Binding Sites

Answer 13

1. ) GABA
2. ) Benzodiazepines
3. ) Barbiturates
4. ) EtOH
5. ) Anesthetics
6. ) Neurosteroids

Question 14

Benzodiazepines

Answer 14

1. ) Diazepam (Valium)
2. ) Clonazepam (Klonopin)
3. ) Alprazolam (Xanax)

Question 15

Barbiturates

Answer 15

1. ) Thiopental (20min)
2. ) Butalbital (3-8h)
3. ) Phenobarbital (1-2d)

Question 16

Barbit vs. Benzos: Hypnosis

Answer 16

Both

Question 17

Barbit vs. Benzos: Anesthesia

Answer 17

Barbiturates ONLY

Question 18

Barbit vs. Benzos: Anti-Seizure

Answer 18

Both

Question 19

Barbit vs. Benzos: Muscle Relaxant

Answer 19

Benzodiazepines ONLY

Question 20

Barbit vs. Benzos: Anti-Anxiety

Answer 20

Benzodiazepines ONLY

a-2 Receptors (BZD-2)

Question 21

Barbit vs. Benzos: Addiction

Answer 21

Both

Question 22

Barbit vs. Benzos: Death

Answer 22

Barbiturates ONLY

Question 23

GABA-A1 receptor: Effects (4)

Answer 23

Sedative/Hypnotic
Amnesia
Anti-seizure
Addiction

Question 24

GABA-A2: Effect

Answer 24

Anti-anxiety

Question 25

Competitive GABA Inhibitor

Answer 25

Bicucculine

Question 26

Non-Competitive GABA Ion Channel Blocker (4)

Answer 26

1. ) Picrotoxin
2. ) Thujone (wormwood extract, Absinthe)
3. ) Fipronil (insecticide)
4. ) Pentylenetetrazol (convulsant)

Question 27

GABA-T Inhibitor

Answer 27

GABA-transaminase
-converts GABA to glutamate

Vigabatrin

Question 28

GAD

Answer 28

Glutamic acid decarboxylase (GAD)

-converts glutamate to GABA

Question 29

GAT-1 inhibitor

Answer 29

GABA transporter-1
-brings extracellular GABA back into astrocytes and presynaptic terminals

Tiagabine