TABLE 1.

Comparison of the Apparent Affinity Constants of Nicotinic Ligands in the Adult Frog Optic Tectum With Those Found in Adult Mammalian Nervous Tissue¹

Ligand	Frog	Rat	Mouse	Human
	(nM)
[3H]Cytisine	0.47 ± 0.04	0.44 ± 0.14	1.5 ± 0.72	0.21 ± 0.087
[125I]α-Bungarotoxin	0.81 ± 0.19	0.62 ± 0.015	∼0.323	∼0.76

¹All values are the mean ± S.E.M. (if available).

²Marks et al., 1986.

³Fiedler et al., 1987.

⁴Khan et al., 1994.

⁵Barrantes et al., 1995.

⁶Purified recombinant human α7 nAChR, Gopalakrishnan et al., 1995.

⁷Purified recombinant human α4β2 nAChR, Gopalakrishnan et al., 1997.