Table 4.
Paired Student's t test comparisons of the time spent in the drug-paired compartment during the preconditioning and test phases, in mice lacking μ-, δ-, or κ-opioid receptor
| MOR | |||||
|---|---|---|---|---|---|
| pre-cond | test | t | p | ||
| +/+ | VEHICLE | 677 ± 63 | 672 ± 92 | t(1,13) = 0.075 | p = 0.942 |
| THC1 | 589 ± 64 | 874 ± 71 | t(1,12) = −6.958 | p < 0.01 | |
| THC5 | 651 ± 58 | 296 ± 76 | t(1,12) = 2.932 | p < 0.05 | |
| −/− | VEHICLE | 607 ± 65 | 611 ± 79 | t(1,13) = 0.076 | p = 0.941 |
| THC1 | 615 ± 65 | 573 ± 71 | t(1,13) = 0.477 | p = 0.641 | |
| THC5 | 574 ± 51 | 394 ± 77 | t(1,12) = 1.091 | p = 0.297 | |
| DOR | |||||
|---|---|---|---|---|---|
| pre-cond | test | t | p | ||
| +/+ | VEHICLE | 734 ± 66 | 733 ± 75 | t(1,8) = 0.035 | p = 0.973 |
| THC1 | 590 ± 62 | 780 ± 63 | t(1,12) = −3.739 | p < 0.01 | |
| THC5 | 589 ± 45 | 359 ± 71 | t(1,12) = 3.253 | p < 0.01 | |
| −/− | VEHICLE | 582 ± 91 | 576 ± 107 | t(1,9) = 0.070 | p = 0.945 |
| THC1 | 578 ± 61 | 879 ± 53 | t(1,11) = −4.443 | p < 0.001 | |
| THC5 | 620 ± 54 | 330 ± 79 | t(1,12) = 3.31 | p < 0.01 | |
| KOR | |||||
|---|---|---|---|---|---|
| pre-cond | test | t | p | ||
| +/+ | VEHICLE | 612 ± 57 | 606 ± 51 | t(1,11) = 1.013 | p = 0.333 |
| THC1 | 531 ± 87 | 745 ± 86 | t(1,10) = −2.971 | p < 0.05 | |
| THC5 | 663 ± 69 | 308 ± 72 | t(1,11) = 4.142 | p < 0.01 | |
| −/− | VEHICLE | 604 ± 106 | 572 ± 89 | t(1,9) = 0.022 | p = 0.983 |
| THC1 | 573 ± 66 | 788 ± 90 | t(1,11) = −3.670 | p < 0.01 | |
| THC5 | 563 ± 45 | 493 ± 67 | t(1,10) = 0.343 | p = 0.739 | |
Values of time spent in the drug-paired compartment during the preconditioning and test phases are expressed in seconds. Paired Student's t test was used to compare the time spent in the drug-paired side during preconditioning and test phases within each group of mice. See Materials and Methods for details. The significant differences between time spent in the drug-paired compartment during the preconditioning and test phases observed in MOR +/+ mice with 1 and 5 mg/kg THC were abolished in MOR −/− mice. The significant difference between time spent in the drug-paired compartment during the preconditioning and test phases observed in KOR +/+ mice with 5 mg/kg THC was abolished in KOR −/− mice.