TABLE 1

Receptor activation by GABA and P4S

The first column shows the constructs injected. The next three columns show the Hill coefficient, EC50, and maximal amplitude relative to 1 mM GABA for fits of the Hill equation (I = Imax {([GABA]/EC50)nH}/{1 + ([GABA]/EC50)nH}) to concentration-response data for GABA. The final column shows the relative response to 1 mM P4S compared with the response (for the same oocyte) to 1 mM GABA. Values shown are mean ± S.E. (number of oocytes), probability for a significant difference to βα γβα. Probabilities Dunnett correction after ANOVA to correct for multiple comparisons.

Constructs
GABA nH
GABA EC50
Imax
P4S Gating
μM
βα γβα 1.35 ± 0.06 (15),— 118 ± 16 (15),— 1.06 ± 0.02 (15),— 0.04 ± 0.01 (8),—
βα γβαL 1.30 ± 0.05 (6) ns 128 ± 19 (6) ns 1.09 ± 0.01 (6) ns 0.04 ± 0.01 (6) ns
βαL γβα 1.32 ± 0.07 (6) ns 218 ± 36 (6)** 1.15 ± 0.03 (6) ns 0.02 ± 0.00 (6) ns
βαL γβαL 1.27 ± 0.09 (5) ns 327 ± 34 (5)*** 1.26 ± 0.06 (5)*** 0.01 ± 0.00 (8) ns
βα γβαW 1.27 ± 0.11 (5) ns 74 ± 11 (5) ns 1.04 ± 0.02 (5) ns 0.13 ± 0.03 (6) ns
βαW γβα 1.13 ± 0.06 (4) ns 52 ± 3 (4) ns 1.06 ± 0.02 (4) ns 0.17 ± 0.03 (7)**
βαW γβαW
1.34 ± 0.08 (9) ns
32 ± 4 (9)**
0.99 ± 0.01 (9) ns
0.45 ± 0.05 (8)***

  • —, not applicable; ns, P > 0.05.

    *P < 0.05.

  • ↵** P < 0.01.

  • ↵*** P < 0.001.