Table 1.

Potentiation and inhibition of neuronal nAChRs by Zn²⁺

Receptor	Potentiation			Inhibition
	Maximum (%)	EC50(μm)	nH	IC50(μm)	nH
α2β2	140  ± 4	13  ± 7	1.5  ± 0.7	52  ± 30	1.3  ± 0.4
α2β4	200  ± 5	45  ± 6	1.4  ± 0.2	590  ± 180	1.8  ± 0.3
α3β2				97  ± 16	0.6  ± 0.1
α3β4	140  ± 2	47  ± 9	1.2  ± 0.2	3200  ± 1400	1.3  ± 0.6
α4β2	260  ± 17	16  ± 4	1.5  ± 0.5	440  ± 140	1.3  ± 0.6
α4β4	560  ± 17	22  ± 4	1.4  ± 0.3	510  ± 37	2.5  ± 0.4
α3-216-α4β4	170  ± 5	9  ± 3	1.6  ± 0.7	1100  ± 700	1.4  ± 0.9
α4-216-α3β4	250  ± 10	26  ± 4	1.6  ± 0.4	660  ± 62	2.3  ± 0.4

Maximum ACh-induced current in the presence of Zn²⁺is presented as a percentage of the control response to ACh alone (see Materials and Methods). For potentiation, EC₅₀ and Hill coefficient (n_H) values were determined by fitting to a Hill equation, and for inhibition, IC₅₀ and Hill coefficient (n_H) values were determined by fitting to a separate Hill equation (see Materials and Methods). All values are the mean ± SEM of three to six oocytes.