The effect of psychoactive drugs on operant behavior induced by microwave radiation

Abstract

A total of five male CF1 mice was trained to escape from or to avoid 2.45‐GHz CW microwave radiation by emitting an operant response. The response consisted of an animal's interruption of a light beam passing through a conditioning chamber. If an animal responded while microwaves were on, radiation was terminated and remained off for 12 seconds (an escape response). If an animal responded during the off period, each response (constituting avoidance) would reset a timer that delayed the onset of microwaves for another 12 seconds. All responses involved discriminated cueing by a 2900‐Hz sonic stimulus that was paired with microwave irradiation. Averaged dose rates were approximately 45 mW g−1, but the duration of irradiation varied with the subjects' escape‐avoidance behavior. When stable baselines of responding were established, each subject was tested following administration of each of three psychoactive compounds at varying dosages: chlordiazepoxide, d‐amphetamine, and chlorpromazine. Chlordiazepoxide resulted in a decreased percentage of avoidance responding coupled with an increased percentage of escape responding. A substantial increase in the animals' cumulative exposure to microwaves was also noted when they were dosed with this drug. The data based on administration of chlorpromazine and of d‐amphetamine were highly variable both within and among subjects.