TABLE 1.

TCE lever selection and operant response rates produced by nicotine, mecamylamine, morphine, dizocipline (MK-801), and (PCP)

Data represent the first minute of each 5-min test session. Numerals in brackets indicate the number of animals in the group that emitted sufficient responses to be included in this determination.

Drug	Drug Dose or Vapor Concentration	% TCE-Lever Responding (± S.E.M.)	Response Rate in Responses/s (± S.E.M.)
Nicotine	Air control	1 (0.2)	1.3 (0.2)
	12,000 ppm TCE	99 (0.1)	1.2 (0.1)
	0.1 mg/kg	1 (0.1)	1.3 (0.2)
	0.3 mg/kg	13 (12.5)	1.2 (0.1)
	1 mg/kg	22 (14.3)	0.8 (0.1)
	1.7 mg/kg	1 (0.6) [6/8]	0.7 (0.2)
	2.5 mg/kg	—	0.0 (0.0)
Mecamylamine	Air control	2 (0.2)	1.7 (0.2)
	12,000 ppm TCE	99 (1.0)	1.2 (0.1)
	0.3 mg/kg	1 (0.2)	1.8 (0.2)
	1 mg/kg	1 (0.5)	1.6 (0.2)
	3 mg/kg	1 (0.7)	1.2 (0.2)
	5.6 mg/kg	0 (0)	1.3 (0.2)
Morphine	Air control	0 (0)	1.4 (0.3)
	12,000 ppm TCE	98 (0.3)	1.4 (0.3)
	1 mg/kg	0 (0)	1.2 (0.4)
	1.7 mg/kg	4 (3.9)	1.3 (0.3)
	3 mg/kg	1 (0.7)	1.2 (0.1)
	10 mg/kg	3 (2.2) [3/6]	0.5 (0.2)
Dizocilpine (MK-801)	Air control	17 (12.5)	1.3 (0.2)
	12,000 ppm TCE	97 (2.0)	1.4 (0.2)
	0.03 mg/kg	9 (7.0)	1.2 (0.2)
	0.1 mg/kg	2 (1.2)	1.4 (0.2)
	0.17 mg/kg	13 (12.5)	1.2 (0.3)
	0.3 mg/kg	—	0.2 (0.1)
PCP	Air control	1 (0.3)	1.1 (0.2)
	12,000 ppm TCE	98 (1.0)	1.2 (0.2)
	0.5 mg/kg	2 (1.1)	1.5 (0.3)
	1 mg/kg	4 (1.8)	1.3 (0.3)
	2 mg/kg	14 (11.9)	1.5 (0.3)
	4 mg/kg	6 (2.7)	1.1 (0.2)
	6 mg/kg	9 (7.1) [6/7]	0.7 (0.2)
	8 mg/kg	—	0.4 (0.3)