Table 2. Hill function parameters derived from the curve fitting of allopregnanolone effects on GABA_A receptors.

Experimental model	n	h a	e b (ng/mL)	e c (%)	Threshold dose for max effect (ng/mL)	Ref.
Bovine chromaffin cells	5	2	15	20	–	[47]
Rat hippocampus/cortex	6	2	45	8	600	[45]
Xenopus oocytes	6	2	300	2	1500	[48]
Rat neurons	5	2	18	5	150	[49]
Mouse L-tk cells	8	1.2	9	0.3	300	[50]
Rat dentate granule cells	7	1.15	3.9	5	90	[46]
Rat embryo hippocampal neurons	7	2.8	300	4.8	900	[51]
Median values		2	18	5	450

^aHill coefficient, ^bHill function’s half-saturation constant derived from raw data, ^cHill function’s half-saturation constant derived from data standardized on a 0–100 scale. The half-saturation constant corresponds to the EC₅₀, i.e. the input concentration inducing 50% output response.