Test Drug | Drug Dose | Percentage of N2O Lever Responding (± S.E.M.) | Response Rate in Responses per Second (± S.E.M.) |
---|---|---|---|
mg/kg | |||
Morphine (n = 8) | O2 + vehicle | 2.4 (1.6) | 1.8 (0.1) |
N2O + vehicle | 96.1 (2.5) | 1.6 (0.1) | |
1 | 2.4 (1.6) | 1.7 (0.1) | |
3 | 15.1 (12.2) | 1.3 (0.2) | |
10 | 3.3 (2.2) | 0.9 (0.2)* | |
30 | 33.3 (33.3) [3/8] | 0.1 (0.0)* | |
U-50488H (n = 8) | O2 + vehicle | 2.4 (1.5) | 1.5 (0.1) |
N2O + vehicle | 95.8 (2.4) | 1.3 (0.1) | |
1 | 2.4 (1.6) | 1.7 (0.1) | |
3.2 | 1.6 (1.6) [5/8] | 0.9 (0.3)* | |
7 | 10.7 (10.7) [3/8] | 0.1 (0.1)* | |
SNC-80 (n = 8) | O2 + vehicle | 1.9 (1.3) | 1.7 (0.1) |
N2O + vehicle | 93.0 (0.8) | 1.5 (0.2) | |
1 | 1.4 (0.8) | 1.7 (0.1) | |
10 | 10.3 (2.9) | 1.2 (0.1)* | |
17 | 7.9 (3.0) | 1.1 (0.2)* | |
30 | 8.7 (1.8) [7/8] | 0.8 (0.2)* | |
56 | 6.8 (1.8) [5/8] | 0.5 (0.2)* | |
Ethanol (n = 9) | O2 + vehicle | 2.3 (1.5) | 1.6 (0.1) |
N2O + vehicle | 96.6 (1.5) | 1.3 (0.2) | |
1000 | 9.6 (6.6) | 1.4 (0.1)* | |
1500 | 11.6 (5.5) | 1.3 (0.1)* | |
2000 | 44.9 (15.3) | 0.8 (0.1)* | |
2500 | 55.0 (13.2) | 0.4 (0.1)* | |
mCPP (n = 8) | O2 + vehicle | 2.6 (1.7) | 1.7 (0.1) |
N2O + vehicle | 96.9 (1.7) | 1.6 (0.1) | |
0.1 | 1.9 (1.1) | 1.8 (0.1) | |
1 | 2.0 (1.3) | 1.6 (0.1) | |
5.6 | 3.4 (1.7) | 0.9 (0.2)* | |
10 | 20.6 (17.0) [5/8] | 0.4 (0.2)* | |
8-OH DPAT (n = 8) | O2 + vehicle | 1.6 (1.6) | 1.6 (0.1) |
N2O + vehicle | 98.3 (1.5) | 1.5 (0.1) | |
0.1 | 1.6 (1.6) | 1.4 (0.1) | |
0.3 | 1.4 (1.1) | 1.1 (0.1)* | |
1 | 1.1 (1.1) [7/8] | 0.5 (0.1)* | |
1.56 | 4.3 (2.4) [6/8] | 0.4 (0.1)* |
↵* Statistically significant (P < 0.05) difference in response rates compared with the oxygen + vehicle control condition.