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The Effect of Microwave Irradiation on the Turnover Rate of Serotonin and Norepinephrine in Rat Brain

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Solomon H. Snyder, M.D. · 1970

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1970 research examined whether microwave radiation disrupts brain neurotransmitter chemistry, highlighting decades-old scientific concern about EMF neurological effects.

Plain English Summary

Summary written for general audiences

This 1970 study investigated how microwave radiation affects the turnover rates of serotonin and norepinephrine, two critical neurotransmitters that regulate mood, behavior, and brain function in rats. The research represents early scientific exploration into whether microwave exposure can disrupt the brain's chemical messaging system. This work laid groundwork for understanding potential neurological effects from microwave radiation exposure.

Why This Matters

This research from 1970 represents pioneering work examining whether microwave radiation can disrupt brain chemistry at the most fundamental level. Serotonin and norepinephrine are neurotransmitters that control everything from mood and sleep to stress response and cognitive function. The fact that researchers were investigating microwave effects on these critical brain chemicals five decades ago shows the longstanding scientific concern about EMF's neurological impacts.

What makes this particularly relevant today is that we're now surrounded by microwave-emitting devices that didn't exist in 1970. Your WiFi router, cell phone, and microwave oven all operate in similar frequency ranges to what these researchers were studying. While we don't know the specific findings from this early study, the research question itself demonstrates that scientists recognized early on that microwave radiation might interfere with the brain's delicate chemical balance.

Finding

At this low level of irradiation, we found that after 7 days exposure for 8 hours per day, there was a marked slowing of serotonin turnover in rat brain. This suggests that microwave irradiation decreased the firing rate of serotonin neurons in the brain.

In their words

At this low level of irradiation, we found that after 7 days exposure for 8 hours per day, there was a marked slowing of serotonin turnover in rat brain. This suggests that microwave irradiation decreased the firing rate of serotonin neurons in the brain.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 3.06 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 3.06 GHzPower lines50/60 HzCell phones~1 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study. Duration: 1 hour for acute exposure; 8 hours/day for 7 days for chronic exposure

Study Details

To examine the effect of microwave irradiation on the turnover rate of serotonin and norepinephrine in rat brain, specifically investigating acute and chronic exposure effects on these neurotransmitter systems.

Male rats (150-250 g) were maintained in individual lucite cubicles (5" x 5" x 10") in which air hol...

Acute effects of microwave irradiation: One hour's irradiation of 200 g male rats at a power level o...

This investigation has been concerned with the effect of microwave irradiation on the turnover rate of serotonin and norepinephrine in rat brain. There is evidence that microwave irradiation at low levels produces in humans and experimental animals somnolence and irritability. Since the serotonin neuronal system in the brain is known to participate in the regulation of sleep and level of attention, and since brain norepinephrine has been implicated as playing a role in central stimulation, the turnover of these two amines were examined. When rats were acutely exposed for one hour to microwave irradiation at 40 mW/cm² there was a significant acceleration of serotonin turnover. Since the body temperature of these animals was elevated by about 3°C, it is possible that this was an effect of "heat stress", a procedure which is known to increase the rate of serotonin turnover. The most striking results of the study were obtained when rats were exposed to low levels (10 nW/cm²) microwave irradiation 8 hours a day for seven days and were sacrificed one day following the last day of microwave exposure. Under these conditions, at the time serotonin turnover was estimated rats had a normal body temperature and showed no apparent behavioral abnormalities. Nonetheless there was a dramatic slowing of serotonin turnover to a rate of 1/4 that of control animals treated identically except for the absence of microwave exposure. This marked decrease in serotonin turnover is the most pronounced effect on the turnover rate of this amine that has been reported following any drug or other treatment to our knowledge. Since serotonin turnover rates presumably reflect the firing rate of the serotonin neurons, this result suggests that the firing of serotonin neurons in the brain is markedly slowed following chronic low level microwave irradiation. Results suggest also that measurement of serotonin turnover is a sensitive tool for detecting effects of low levels of microwave irradiation on brain function.

Cite This Study
Solomon H. Snyder, M.D. (1970). The Effect of Microwave Irradiation on the Turnover Rate of Serotonin and Norepinephrine in Rat Brain.
Show BibTeX
@article{the_effect_of_microwave_irradiation_on_the_turnover_rate_of_serotonin_and_norepi_g6839,
  author = {Solomon H. Snyder and M.D.},
  title = {The Effect of Microwave Irradiation on the Turnover Rate of Serotonin and Norepinephrine in Rat Brain},
  year = {1970},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

The study specifically investigated serotonin and norepinephrine turnover rates in rat brains. These neurotransmitters control mood, sleep, stress response, and cognitive function, making them critical indicators of brain health and neurological function.
Scientists recognized early that microwave radiation might disrupt the brain's delicate chemical messaging system. This research represents pioneering work investigating whether EMF exposure could interfere with neurotransmitter function decades before widespread consumer microwave device adoption.
Turnover rate measures how quickly the brain produces, uses, and breaks down neurotransmitters like serotonin and norepinephrine. Changes in these rates can indicate altered brain function, potentially affecting mood, behavior, sleep, and cognitive performance.
This research represents some of the earliest scientific investigation into microwave radiation's potential neurological effects. It established the research framework for examining EMF impacts on brain chemistry decades before widespread consumer exposure to microwave-emitting devices.
Today's WiFi routers, cell phones, and household devices operate in similar microwave frequency ranges studied in 1970. However, modern exposures are typically lower power but continuous, unlike the controlled laboratory conditions used in early research.