Abstract
Effect of B1and related agents on the operant behaviors in rats was studied, using a commercially available apparatus. Two schedules of the food reinforcement with a fixed ratio (FR-30) and a fixed interval (FI-60) and a schedule of discriminated avoidance response (DAR) were used for the conditioned behaviors.
In the FR-30 and FI-60 schedules, B1, B1-P and B1-PP administered intraventricularly 10-50 μg/rat or subcutaneously 100-200 mg/kg, produced the dose-related decreases in the behaviors. In the DAR schedule, B1, B1-P and B1-PP did not produce significant alteration.
The suppressive effect in the food reinforcement schedule by B1, histamine B1-P and B1-PP was partially antagonized by the simultaneous administration of tripelennamine, an antihistaminic.
A large dose of B1caused an elevation of histamine level in the brain of mouse approximately 25%.
From these results, a possibility that the suppressive effect of B1on the operant behaviors may be responsible for histamine in the brain, is discussed.
