Table 1.

Summary data for ACh concentration/response curves obtained using HEPES and phosphate ND-96 recording buffer (Fig. 1).

Receptor	Buffer	pEC50 ± S.E.M. (EC50 μM)	nH ± S.E.M.
HS	HEPES	5.7 ± 0.1 (2.2)	0.9 ± 0.2
HSβ2D218A	HEPES	5.5 ± 0.1 (3.5)	1.1 ± 0.3
LS	HEPES	4.3 ± 0.1 (54)	1.2 ± 0.1
LSβ2D218A	HEPES	3.83 ± 0.04 (150)	1.0 ± 0.1
HS	Phosphate	5.4 ± 0.1 (3.7)	1.0 ± 0.2
HSβ2D218A	Phosphate	5.7 ± 0.2 (2.1)	0.9 ± 0.3
LS	Phosphate	4.5 ± 0.1 (32)	1.2 ± 0.2
LSβ2D218A	Phosphate	4.2 ± 0.2 (58)	0.8 ± 0.2