PMC

Table showing the different GABA_A/C receptor subunits.

The fold increase by THDOC (A) and tracazolate (B) is shown with a saturating concentration of GABA (100 μM) from oocytes expressing α₁β₂ (black bar) and α₁β₂δ (gray bar) GABA_A receptors.

Bar graphs plotting the maximum currents of α₁β₂ (I_max =2736 ± 306, n=23; black bar), α₁β₂δ (I_max =55 ± 5, n=39; open bar), α₁β₂γ_2s (I_max =6949±354, n=42; gray bar) and α₁β₂δ(L9’S)(I_max=4565±372, n=8) GABA_A receptors. Compared to α₁β₂δ, α₁β₂, α₁β₂γ_2s and α₁β₂δ (L9’S) show 50-fold, 126-fold and 83-fold increases in the maximum GABA_A-activated currents, respectively.

Ligand-gated ionic channel (LGICs) structure. A. Each GABA_A receptor subunit contains four transmembrane domains (TM). B. The TM2 domain forms the wall of the channel pore. C. The majority of native GABA_A receptors are composed of 2α, 2β and 1γ subunit.