Nomenclature	α1	α2	α3	α4	α5	α6
HGNC, UniProt	GABRA1, P14867	GABRA2, P47869	GABRA3, P34903	GABRA4, P48169	GABRA5, P31644	GABRA6, Q16445
Agonists	isoguvacine [GABA site] (Full agonist), isonipecotic acid [GABA site], muscimol [GABA site] (Full agonist), piperidine-4-sulphonic acid [GABA site] (Full agonist), THIP [GABA site]
Selective antagonists	bicuculline [GABA site], gabazine [GABA site]
Channel Blockers	picrotoxin, TBPS
Endogenous allosteric regulators	5α-pregnan-3α-ol-20-one (Potentiation), tetrahydrodeoxycorticosterone (Potentiation), Zn2+ (Inhibition)
Allosteric Regulators [benzodiazepine site]	α3IA (Inverse agonist), α5IA (Inverse agonist), bretazenil (Full agonist), diazepam (Full agonist), DMCM (Inverse agonist), flumazenil (Antagonist), flunitrazepam (Full agonist), MRK016 (Inverse agonist), Ro154513 (Inverse agonist), Ro194603 (Inverse agonist), Ro4938581 (Inverse agonist), TP003 (Antagonist), TPA023 (Antagonist)	α3IA (Inverse agonist), α5IA (Inverse agonist), bretazenil (Full agonist), diazepam (Full agonist), DMCM (Inverse agonist), flumazenil (Antagonist), flunitrazepam (Full agonist), MRK016 (Inverse agonist), ocinaplon (Partial agonist), Ro154513 (Inverse agonist), Ro194603 (Inverse agonist), Ro4938581 (Inverse agonist), TP003 (Antagonist), ZK93426 (Antagonist)	α5IA (Inverse agonist), bretazenil (Full agonist), diazepam (Full agonist), DMCM (Inverse agonist), flumazenil (Antagonist), flunitrazepam (Full agonist), MRK016 (Inverse agonist), ocinaplon (Partial agonist), Ro154513 (Inverse agonist), Ro4938581 (Inverse agonist), ZK93426 (Antagonist)	flumazenil (Partial agonist, low affinity)	α3IA (Inverse agonist), bretazenil (Full agonist), diazepam (Full agonist), DMCM (Inverse agonist), flumazenil (Antagonist), flunitrazepam (Full agonist), ocinaplon (Partial agonist), Ro154513 (Inverse agonist), Ro194603 (Inverse agonist), TP003 (Antagonist), TPA023 (Antagonist), ZK93426 (Antagonist)	bretazenil (Full agonist), flumazenil (Partial agonist, low affinity)
Selective allosteric regulators [benzodiazepine site]	indiplon (Full agonist, high affinity), L838417 (Antagonist), ocinaplon (Full agonist), zaleplon (Full agonist, high affinity), ZK93426 (Antagonist), zolpidem (Full agonist, high affinity)	L838417 (Partial agonist), TPA023 (Partial agonist, low efficacy)	α3IA (higher affinity), L838417 (Partial agonist), Ro194603 (Inverse agonist, higher affinity), TP003 (Partial agonist, high efficacy), TPA023 (Partial agonist, low efficacy)	bretazenil (Full agonist), Ro154513 (Full agonist)	α5IA (Inverse agonist), L655708 (Inverse agonist, high affinity), L838417 (Partial agonist), MRK016 (Inverse agonist), Ro4938581 (Inverse agonist, higher affinity), RY024 (Inverse agonist, high affinity)	Ro154513 (Full agonist)
Radioligands (Kd)	[11C]flumazenil [benzodiazepine site], [18F]fluoroethylflumazenil [benzodiazepine site], [35S]TBPS [anion channel], [3H]CGS8216 [benzodiazepine site], [3H]flunitrazepam [benzodiazepine site], [3H]gabazine [GABA site], [3H]muscimol [GABA site], [3H]zolpidem [benzodiazepine site]
Comment	Zn2+ is an endogenous allosteric regulator and causes potent inhibition of receptors formed from binary combinations of α and β subunits, incorporation of a δ or γ subunit causes a modest, or pronounced, reduction in inhibitory potency, respectively 77