Chronic administration during early adulthood does not alter the hormonally-dependent disruptive effects of delta-9-tetrahydrocannabinol (DELTA~9-THC) on complex behavior in female rats

摘要

This study examined whether chronic DELTA~9-THC during early adulthood would produce the same hormonally-dependent deficits in learning that are produced by chronic DELTA~9-THC during adolescence. To do this, either sham-operated (intact) or ovariectomized (OVX) female rats received daily saline or 5.6 mg/kg of DELTA~9-THC i.p. for 40 days during early adulthood. Following chronic administration, and a drug-free period to train both a learning and performance task, acute dose-effect curves for DELTA~9-THC (0.56-10 mg/kg) were established in each of the four groups (intact/saline, intact/THC, OVX/saline and OVX/THC). The dependent measures of responding under the learning and performance tasks were the overall response rate and the percentage of errors. Although the history of OVX and chronic DELTA~9-THC in early adulthood did not significantly affect non-drug or baseline behavior under the tasks, acute administration of DELTA~9-THC produced both rate-decreasing and error-increasing effects on learning and performance behavior, and these effects were dependent on their hormone condition.