Intraseptal microinjection of beta-funaltrexamine blocked a microwave-induced decrease of hippocampal cholinergic activity in the rat.
Acute (45 min) exposure to pulsed (2 microseconds pulse width, 500 pulses per second) 2450-MHz microwaves at a power density of 1 mW/cm2 (whole body specific absorption rate 0.6 W/kg) microwaves caused a decrease in cholinergic activity in the hippocampus of the rat as measured by the sodium-dependent high-affinity choline uptake. Microinjection of beta-funaltrexamine (1 microgram) into the septum before microwave exposure blocked this effect. These data indicate that mu-opioid receptors in the septum mediate a microwave-induced decrease in cholinergic activity in the hippocampus and support our hypothesis that microwaves at a whole body SAR of 0.6 W/kg can activate endogenous opioids in the brain.
Lai
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Department of Pharmacology, University of Washington, Seattle 98195, USA. hlai@u.washington.edu
Carino
M A
MA
Horita
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Guy
A W
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D000818:Animals; D002794:Choline / Q000378:metabolism; D002799:Cholinergic Fibers / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009292:Narcotic Antagonists; D009271:Naltrexone; C024524:beta-funaltrexamine; D002794:Choline