Naltrexone pretreatment blocks microwave-induced changes in central cholinergic receptors

✍ Scribed by H. Lai; M. A. Carino; Y. F. Wen; A. Horita; A. W. Guy

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 413 KB
• Volume: 12
• Category: Article
• ISSN: 0197-8462
• DOI: 10.1002/bem.2250120105

✦ Synopsis

Repeated exposure of rats to pulsed, circularly polarized microwaves (2,450-MHq 2 -p ~ pulses at 500 pps, power density 1 mW/cm2, at an averaged, whole-body SAR of 0.6 W/kg) induced biphasic changes in the concentration of muscarinic cholinergic receptors in the central nervous system. An increase in receptor concentration occurred in the hippocampus of rats subjected to ten 45-min sessions of microwave exposure, whereas a decrease in concentration was observed in the frontal cortex and hippocampus of rats exposed to ten 20-min sessions. These findings, which confirm earlier work in the authors' laboratory, were extended to include pretreatment of rats with the narcotic antagonist naltrexone (1 mg/ kg, IP) before each session of exposure. The drug treatment blocked the microwaveinduced changes in cholinergic receptors in the brain. These data further support the authors' hypothesis that endogenous opioids play a role in the effects of microwaves on central cholinergic systems.