Table 1.
Effects of ICV or intra-VTA OFQ/N administration on basal motor activity and cocaine-induced motor stimulation. Rats were treated with aCSF or OFQ/N either ICV or directly into the VTA prior to saline or cocaine administration. The same treatment was given for 3 days, except the dose of OFQ/N was doubled on each subsequent day. Rats were left untreated until day 8, when a challenge dose of cocaine alone (7.5 mg/kg, IP) was administered. Values represent means (±SEM) of total distance traveled (cm) during the entire 1-h period after cocaine administration
| Treatment | aCSF-SAL | aCSF-COC | OFQ/N-SAL | OFQ/N-COC |
|---|---|---|---|---|
| ICV OFQ/N | ||||
| Day 1 | 974.8±186.8 | 11,134.7±2520.6 | 315.9±73.5 | 2355.2±717.6 |
| Day 2 | 848.3±215.1 | 12,739.9±1656.2 | 565.4±138.3 | 3280.9±850.9 |
| Day 3 | 739.0±125.4 | 15,274.1±1256.6 | 485.7±104.8 | 2536.0±760.2 |
| Day 8 | 2144.9±324.3 | 5449.5±1,005.3 | 3225.6±922.5 | 2314.7±621.1 |
| Intra-VTA OFQ/N | ||||
| Day 1 | 1018.4±356.8 | 11,285.9±3,152.1 | 322.3±115.9 | 3117.5±884.0 |
| Day 2 | 868.8±286.2 | 12,172.2±2,432.6 | 613.8±199.0 | 3474.8±1,231.5 |
| Day 3 | 726.7±229.9 | 17,346.5±1,756 | 793.0±436.7 | 5721.3±1,117.5 |
| Day 8 | 3323.7±426.8 | 9025.8±977.9 | 5239.3±1,149.2 | 4300.5±1,026.8 |