Single injections of triazolam, a short-acting benzodiazepine, lengthen the period of the circadian activity rhythm in golden hamsters

Single injections of the benzodiazepine, triazolam, induce phase shifts and cause a lengthening of the circadian activity rhythm in the golden hamster. The effect of triazolam on period depends on the phase of injection, but is not dependent on the direction of the phase shifts. Triazolam injections caused increases in period that were associated with phase advances as well as phase delays in the activity rhythm. This relationship between triazolam-induced phase shifts and changes in period is different from the relationship between light-induced phase shifts and period changes.