Study type: Medical/biological study (experimental study)

Amino acid concentrations in hypothalamic and caudate nuclei during microwave-induced thermal stress: analysis by microdialysis med./bio.

Published in: Bioelectromagnetics 1997; 18 (3): 277-283

Aim of study (acc. to author)

To investigate the effects of thermal stress produced by exposure to 5.02 GHz irradiation on amino acid concentration in the hypothalamus and caudate nucleus of rats.



Exposure Parameters
Exposure 1: 5.02 GHz
Modulation type: pulsed
Exposure duration: 40 min
  • SAR: 40 mW/g average over time (cf. remarks) (for the left side of the brain.)
  • SAR: 29 mW/g average over time (cf. remarks) (for right side of the brain.)
  • power: 50 W mean (set initially, later on set between 0 to 10 W.)

Exposure 1

Main characteristics
Frequency 5.02 GHz
Exposure duration 40 min
Modulation type pulsed
Pulse width 10 µs
Repetition frequency 1,000 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.095 m
Chamber Anechoic chamber
Setup Rat laid on its right side with its left side of the head and neck placed directly under the wave guide.
Additional info Long axis of the rat`s body was parallel to the EF.
Measurand Value Type Method Mass Remarks
SAR 40 mW/g average over time - cf. remarks for the left side of the brain.
SAR 29 mW/g average over time - cf. remarks for right side of the brain.
power 50 W mean calibration - set initially, later on set between 0 to 10 W.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure

Main outcome of study (acc. to author)

In the hypothalamus and caudate nucleus, the concentrations of aspartic acid, serine, and glycine increased significantly during exposure. These findings indicate that radiofrequency-induced thermal stress produces a general change in the amino acid concentrations that is not restricted to thermoregulatory centers (hypothalamus). Changes in the concentrations of glutamic acid and glutamine were not statistically significant. Altered amino acid concentrations may reveal which brain regions are susceptible to damage in response to radiofrequency-induced thermal stress.

Study character:

Study funded by

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