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Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.

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Lai H, Carino MA, Horita A, Guy AW · 1992

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Single microwave exposure increased benzodiazepine receptor concentration in the rat cerebral cortex, but repeated exposure showed no significant change.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to single 45-minute and repeated daily 45-minute microwave sessions at 2450 MHz, 1 mW/cm², with a whole-body SAR of 0.6 W/kg. After a single exposure, receptor concentration increased in the cerebral cortex but not in the hippocampus or cerebellum. No significant change in binding affinity of the receptors was observed in any of the brain regions studied. After repeated exposures, no significant change in receptor concentration was found in the cerebral cortex. Handling and exposure procedures did not significantly affect benzodiazepine receptors.

Why This Matters

The study aimed to compare single versus repeated microwave exposure effects on benzodiazepine receptors in the rat brain. The authors suggest that low-intensity microwave irradiation may act as a stressor because benzodiazepine receptors are responsive to anxiety and stress. Receptor binding was measured using a 3H-flunitrazepam ligand assay.

Exposure Details

SAR
0.6 W/kg
Power Density
1 mW/cm²
Source/Device
2450 MHz
Exposure Duration
45 min And repeated ten daily 45-min sessions

Exposure Context

This study used 1 mW/cm² for radio frequency:

This study used 0.6 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 1 mW/cm²Extreme Concern - 1,000 µW/m²FCC Limit - 10M µW/m²Effects observed in the Extreme Concern range (Building Biology)This level is 1 times the FCC limit
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 2.45 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 2.45 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The aim of this study is to observe Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.

We studied the effects of single (45 min) and repeated (ten daily 45-min sessions) microwave exposur...

Immediately after a single exposure, an increase in the concentration of receptor was observed in th...

Because benzodiazepine receptors in the brain are responsive to anxiety and stress, our data support the hypothesis that low-intensity microwave irradiation can be a source of stress.

Cite This Study
Lai H, Carino MA, Horita A, Guy AW (1992). Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat. Bioelectromagnetics 13(1):57-66, 1992.
Show BibTeX
@article{h_1992_single_vs_repeated_microwave_1136,
  author = {Lai H and Carino MA and Horita A and Guy AW},
  title = {Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.},
  year = {1992},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/1312845/},
}
PubMed: 1312845

Cited By (51 papers)

View all 51 citing papers on Semantic Scholar

Quick Questions About This Study

The study used 2450-MHz microwave exposure at 1 mW/cm² with a whole-body SAR of 0.6 W/kg, pulsed at 500 pps with 2-microsecond pulse width.
The study used a single 45-minute microwave exposure. After a single exposure, receptor concentration increased in the cerebral cortex but not in the hippocampus or cerebellum.
The repeated exposure consisted of ten daily 45-minute sessions. After repeated exposures, no significant change in receptor concentration was found in the cerebral cortex.
Handling and exposure procedures did not significantly affect benzodiazepine receptors in the brain.
The researchers used a receptor-binding assay with 3H-flunitrazepam as the ligand.