The applicants propose experiments to further investigate the neural mechanisms involved in the neurological effects of low-level microwave irradiation in the rat. In previous research, the applicants found that acute low-level microwave exposure changed the activity of the cholinergic systems in the rat brain, and after repeated exposure, changes occurred in the muscarinic cholinergic receptors. Furthermore, the applicants found that the effects were mediated by endogenous opioids and corticotropin- releasing factor (CRF) in the brain. To further study the neural mechanisms involved, this proposal has the following objectives: 1) to reveal the subtypes of muscarinic cholinergic receptors (M1 and M2) in the brain affected by low-level microwaves; 2) to investigate the subtypes of endogenous opioid receptors (i.e., mu, delta, and kappa) and the loci in the brain where they mediate the microwave-induced changes in cholinergic activity; and to study the possible changes in opioid receptors in the brain after repeated microwave exposure and 3) to determine the location in the brain where CRF mediates the microwave-induced changes in central cholinergic activity. In addition, since the applicant has also found that low-level microwave irradiation affects spatial learning and memory functions, further experiments are proposed to study the neural mechanisms involved in the learning deficient.

National Institute of Health (NIH)
National Institute of Environmental Health Sciences (NIEHS)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (SSS (R1))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Washington
Schools of Medicine
United States
Zip Code
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

Showing the most recent 10 out of 19 publications