Study type: Medical/biological study (experimental study)

Effects of the action of microwave-frequency electromagnetic radiation on the spike activity of neurons in the supraoptic nucleus of the hypothalamus in rats. med./bio.

Published in: Neurosci Behav Physiol 2007; 37 (2): 175-180

Aim of study (acc. to author)

The study describes a comparative analysis of the background spike activity of neurons in the supraoptic nucleus of the hypothalamus after single exposures to low intensity electromagnetic fields at different frequencies, with the aim of assessing the functional state of the central nervous system and identifying a number of features in the action of millimeter wave irradiation on the brain.

Background/further details

Experiments were performed on rats anesthetized with Nembutal (40 mg/kg). Experimental group consisted of 12 rats, control group consisted of 6 rats.
The functional state of the CNS is often assessed by using the background spike activity of neurons. Measurements of spike frequency provide only a partial reflection of the nature of the spike stream, while identification of parameters based on analysis of interspike intervals provides a more informative assessment of spontaneous activity in different physiological processes.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 42.2 GHz
Modulation type: CW
Exposure duration: continuous for 40 min
Exposure 2: 50.3 GHz
Modulation type: CW
Exposure duration: continuous for 40 min

Exposure 1

Main characteristics
Frequency 42.2 GHz
Type
Charakteristic
Exposure duration continuous for 40 min
Additional info stability of ±0.05%
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 40 cm
Setup The anaesthetized animal's head was irradiated in the vertical direction in the far zone to exclude spatial heterogeneity of the field [Gapeev et al., 1996].
Additional info Spike activity was recorded using glass microelectrodes (tip diameter 1 µm, resistance 3-5 MΩ) filled with 2 M NaCl. The stereotaxic orientation of the electrodes was in accordance with coordinates from an atlas, and electrode locations were verified histologically after experiments.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.19 mW/cm² - - - -

Exposure 2

Main characteristics
Frequency 50.3 GHz
Type
Charakteristic
Exposure duration continuous for 40 min
Additional info stability of ±0.05%
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 0.48 mW/cm² - - - -

Reference articles

  • Gapeev AB et al. (1996): [Modification of the activity of murine peritoneal neutrophils upon exposure to millimeter waves at close and far distances from the emitter]

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data show that single sessions of irradiation of animals' heads with low intensity electromagnetic fields in the millimeter wave range were accompanied by insignificant changes in mean spike frequency. Modification of the spike frequency within the normal range and the absence of significant changes provide evidence of the subthreshold (in terms of its biological significance) nature of the actions of low intensity electromagnetic fields on the functioning of the central nervous system, whose responses depend on the initial functional state

Study character:

Study funded by

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