Table 4.

Functional effects of A-to-B substitutions at the 5-HT₃ receptor

Mutants	pEC50 mean ± SE	EC50 (μM)	nH mean ± SE	n
WT A	6.12 ± 0.02	0.75	2.22 ± 0.23	13
Y153H	4.36 ± 0.02∗	43.4	2.94 ± 0.33	7
T181N	5.30 ± 0.01∗	5.07	3.38 ± 0.22∗	8
W183I	4.75 ± 0.02∗	17.7	2.50 ± 0.22	14
F226R	NR∗	-	-	> 30
I228S	4.52 ± 0.02∗	30.4	2.87 ± 0.39	9
Y234F	5.02 ± 0.09∗	9.6	1.82 ± 0.42	6
E236Q	3.95 ± 0.06∗	111	1.54 ± 0.34	7
T181NW183I	3.60 ± 0.03∗	254	1.54 ± 0.18	8
F226RI228S	NR∗	-	-	> 30
Y234FE236Q	3.86 ± 0.01∗	138	3.20 ± 0.20	8

^∗Significantly different from WT. NR = no response (up to 300 μM 5-HT).