Table 3

The effects of Ro 60-0175 on the latency to earn the first cocaine infusion and the mean interinfusion interval for rats self-administering cocaine on the PR schedule

DoseLatency to First InfusionMean Interinfusion Interval
mg/kg s
Vehicle87.4  ± 24.8350.2  ± 42.5
Ro 60-01750.3193.4  ± 94.8329.7  ± 49.4
1272.7  ± 118.7470.5  ± 119.7

The mean interinfusion interval was calculated after excluding the intervals before the first and last infusion. Two rats at 3 mg/kg failed to respond at all during the session; therefore, a group mean for both measures was not calculated.

  • N.D., not determined.