TABLE 1.

Summary of data for activation by GABA, propofol, and combinations of the two agonists

The first column shows the concentrations of GABA and/or propofol (Prop) applied while the second identifies the data sets shown in Figs. 2C and 4A. The column headed ∆P_o gives the mean ± S.E.M. (number of cells) for the measured P_o produced by that agonist or combination of agonists, expressed as the difference from the basal P_o value (0.00012). P vs. ∆P_o predicted gives the P value (one-sample t test) for the difference between the measured and predicted differences (in each case, the predicted response is 0.49988). The column headed ∆Sum gives the arithmetic sum of the predicted responses to the given concentrations of agonists applied separately (e.g., P_o of 2 µM GABA applied alone plus P_o of 4.65 µM propofol applied alone) in terms of the difference from the basal P_o value. The final column (P to ∆Sum) gives the P value for the difference between the measured response and the predicted sum.

Agonists Used	Set	∆Po	P vs. ∆Po Predicted	∆Sum	P vs. ∆Sum
26 μM GABA	1	0.51 ± 0.05 (5)	0.9	0.50	0.9
99 μM Prop	2	0.46 ± 0.06 (5)	0.5	0.50	0.5
2 μM GABA + 4.65 μM Prop	3	0.49 ± 0.06 (6)	0.9	0.02	0.001
5 μM GABA + 2.1 μM Prop	4	0.45 ± 0.03 (5)	0.2	0.08	<0.001
10 μM GABA + 0.94 μM Prop	5	0.49 ± 0.04 (7)	0.8	0.22	<0.001
15 μM GABA + 0.46 μM Prop	6	0.52 ± 0.05 (7)	0.7	0.34	0.01
20 μM GABA + 0.19 μM Prop	7	0.55 ± 0.03 (7)	0.2	0.42	0.006