Dosimetric and Behavioral Analysis of Microwave-Drug Synergistic Effects on Operant Behavior in the Rat

摘要

Five male Long-Evans rats, maintained at 80% of their free-feeding weight, were trained to bar-press for food reward on a one-minute fixed-interval (FI1) schedule of reinforcement. Once stable FI1 baseline response rates were established, dose-response functions were generated for Chlordiazepoxide HC1 (CDZ). Subsequent treatments with CDZ were followed by 30 min. pulsed microwave radiation (MWR) and FI1 behavioral assessment. Pulsed MWR exposures were in the far zone of an anechoic chamber at an averaged incident power density of 1 mW/sq cm (PRF = 300/sec, 3 usec pulse width). After 2 replications of the combined treatments another CDZ dose-response function was generated. This was followed by 3 more CDZ and MWR replications the first of which was carried out at an averaged incident power density of 1 mW/ sq cm2 Increased rates of response for the CDZ and 1 mW/sq cm MWR treatment were demonstrated relative to initial CDZ dose-response functions in 4 of 5 rats tested. However, the dose-response functions for CDZ alone, that were generated following this apparent synergy showed the same shift in response rate. Furthur, the 8 mW/sq cm 2 pulsed MWR combined with CDZ also produced data similar to the 1 mW/sq cm post-MWR exposure CDZ dose-response functions for the animals tested. Thus, we were unable to replicate an earlier demonstration of synergy between CDZ and MWR.