Effects of opioids and XXXX in combination with @entity836 on the acquisition and performance of response sequences in monkeys.

@entity4521 @entity836 @entity12781 @entity72273 @entity284
In each of three components of a multiple schedule, monkeys were required to emit a different sequence of four responses in a predetermined order on four levers. Sequence completions produced food under a fixed-ratio schedule. Errors produced a brief timeout. One component of the multiple schedule was a repeated-acquisition task where the four-response sequence changed each session (learning). The second component of the multiple schedule was also a repeated-acquisition task, but acquisition was supported through the use of a stimulus fading procedure (faded learning). In a third component of the multiple schedule, the sequence of responses remained the same from session to session (performance). @entity4521 , @entity284 , @entity72273 and @entity12781 each produced dose-related decreases in overall response rate. At high doses which produced equivalent rate-decreasing effects, @entity72273 and @entity12781 generally produced greater disruption of accuracy in the learning component than did @entity4521 or @entity284 . @entity836 5.6 microgram/kg shifted to the right by approximately 1/2-log unit the @entity4521 and @entity284 dose-effect curves, but produced little or no change in the @entity72273 dose-effect curves. At 56 micrograms/kg @entity836 completely antagonized both the rate-decreasing and error-increasing effects of @entity4521 and @entity284 . The same dose of @entity836 tended to produce greater antagonism of the effects of @entity72273 on accuracy than on rate, which was shifted by only 1/4-log unit. In contrast, @entity836 failed to antagonize the effects of @entity12781 on either rate or accuracy. Thus it would appear that while @entity72273 and @entity12781 produce similar disruptions in the accuracy of a discrimination, the effects of each are differentially sensitive to antagonism by @entity836 .
