Table 2

Lack of generalization of selective antagonists at D₃, D₄, D₁/D₅, and α₁-adrenergic receptors to S-16924 and clozapine discriminative stimulus

Class	Drug	S-16924		Clozapine
Class	Drug	Dose (N)	% GEN	% DRR	Dose (N)	% GEN	% DRR
D₃antagonists	(±)-S-11566	2.5 (5)	20	10	2.5 (5)	20	0
	(+)-S-14297^2-a	1.25 (3)	0	12	ND	ND	ND
D₄antagonists	L-745,870^2-b	2.5 (5)	40	10	2.5 (4)	0	9
	S-18126	10.0 (5)	20	0	2.5 (5)	0	0
D₁/D₅antagonist	SCH-39166	0.04 (5)	20	61	0.04 (5)	0	44
α₁-AR antagonist	Prazosin	0.63 (5)	0	2	0.63 (5)	20	27

N = number of animals; % GEN = % generalization; % DRR = % decrease of response rate, and ND = not determined.
↵2-a Testing discontinued due to cutaneous toxicity: orally not bioavailable.
↵2-b Tested by the oral route owing to pre-established cutaneous toxicity.