Conclusions
AHN 1-055 may be of clinical utility in the treatment of ADHD.
Methods
Rats responded under a delay-discounting procedure in which responses on one lever produced immediate delivery of a single food pellet and alternative responses produced four food pellets either immediately or with various temporal delays, with those delays arranged in ascending or random orders in different groups of rats. Selection of the smaller more immediate reinforcer has been suggested as an aspect of "impulsivity," a trait with suggested involvement in ADHD. Other rats were studied under fixed-interval (FI) 300-s schedules to assess drug effects on behavior under temporal control.
Results
d-Amphetamine, methylphenidate, and the BZT analog AHN 1-055, but not AHN 2-005 or JHW 007, increased selection of the large, delayed reinforcer with either arrangement of delays. All drugs changed the temporal distribution of responses within the FI from one with responses concentrated at the end to a more uniform distribution. Changes in the temporal distribution of FI responding occurred with drugs that did not affect discounting suggesting that discounting does not arise directly from the same temporal control processes controlling FI responding. Conclusions: AHN 1-055 may be of clinical utility in the treatment of ADHD.