We propose experiments to continue our studies on the effects of low-level microwave irradiation on neurological functions in the rat. In previous research, we found that acute exposure to low- level microwaves affected sodium-dependent high-affinity choline uptake, a measure of cholinergic activity in neural tissue, in various regions of the rat brain. Since cholinergic systems in the brain serve important functions, we will use this effect as the dependent variable to study the (interaction effects of different parameters of irradiation: power density, duration, pulsed versus continuous-wave irradiation, and circularly versus plane-polarized waves. Functional consequence of microwave-induced changes in cholinergic activity in the brain will be investigated by studying radial-arm maze performance, a measure of short-term spatial memory. Possible reversal of the learning deficit by treatment with narcotic antagonists will be investigated. Long-term changes in neural functions after repeated exposure will be investigated by measurements of muscarinic cholinergic receptor properties in different regions of the brain. Involvements of other neurotransmitters in the effects of microwaves on central cholinergic activity will be studied by treating animals with various transmitter antagonists before exposure. Data from our research also indicate that some of the neurological effects of low-level microwave exposure are mediated by endogenous opioids. We propose a series of experiments to measure the levels of three types of endogenous opioids: beta-endorphin, met- enkephalin, and leu-enkephalin, in different regions of the brain after acute or repeated exposure to microwaves. It is hoped that results from this proposed research will further our understanding of the neurochemical mechanism mediating the neurological effects of low-level microwave irradiation and the behavioral consequence of these effects.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
2R01ES003712-04
Application #
3251273
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1988-01-01
Project End
1991-12-31
Budget Start
1988-01-01
Budget End
1988-12-31
Support Year
4
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Lai, H; Singh, N P (1997) Melatonin and a spin-trap compound block radiofrequency electromagnetic radiation-induced DNA strand breaks in rat brain cells. Bioelectromagnetics 18:446-54
Lai, H; Singh, N P (1996) Single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation. Int J Radiat Biol 69:513-21
Lai, H; Carino, M A; Horita, A et al. (1996) Intraseptal microinjection of beta-funaltrexamine blocked a microwave-induced decrease of hippocampal cholinergic activity in the rat. Pharmacol Biochem Behav 53:613-6
Lai, H; Singh, N P (1995) Acute low-intensity microwave exposure increases DNA single-strand breaks in rat brain cells. Bioelectromagnetics 16:207-10
Lai, H; Horita, A; Guy, A W (1994) Microwave irradiation affects radial-arm maze performance in the rat. Bioelectromagnetics 15:95-104
Lai, H; Carino, M A; Horita, A et al. (1993) Effects of a 60 Hz magnetic field on central cholinergic systems of the rat. Bioelectromagnetics 14:5-15
Lai, H; Carino, M A (1992) Opioid receptor subtypes mediating the noise-induced decreases in high-affinity choline uptake in the rat brain. Pharmacol Biochem Behav 42:553-8
Lai, H (1992) Research on the neurological effects of nonionizing radiation at the University of Washington. Bioelectromagnetics 13:513-26
Lai, H; Carino, M A; Horita, A et al. (1992) Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat. Bioelectromagnetics 13:57-66
Lai, H; Carino, M A; Horita, A et al. (1992) Opioid receptor subtypes that mediate a microwave-induced decrease in central cholinergic activity in the rat. Bioelectromagnetics 13:237-46

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