Study type: Medical/biological study (experimental study)

Prolonged microwave irradiation of rats: effects on concurrent operant behavior. med./bio.

Published in: Bioelectromagnetics 1981; 2 (2): 169-185

Aim of study (acc. to author)

To study operant behavior in small animals during exposure to pulse modulated microwave irradiation. Two measures of performance were used: 1) cued, fixed-ratio (FR) bar pressing for food reinforcement and 2) noncued bar pressing in the absence of food reinforcement.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.3 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks
Exposure 2: 1.3 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks
Exposure 3: 1.3 GHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks

General information

Animals were divided into two groups of 15 each, one group was sham exposed and the other was MW exposed.

Exposure 1

Main characteristics
Frequency 1.3 GHz
Type
Waveform
Charakteristic
  • guided field
Polarization
  • circular
Exposure duration repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks
Modulation
Modulation type pulsed
Pulse width 1 µs
Packets per second 600
Exposure setup
Exposure source
Additional info Control and exposure animals were tested in identical, cylindrical waveguides
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.5 mW/g mean unspecified whole body -

Exposure 2

Main characteristics
Frequency 1.3 GHz
Type
Waveform
Charakteristic
  • guided field
Polarization
  • circular
Exposure duration repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks
Modulation
Modulation type pulsed
Pulse width 1 µs
Packets per second 600
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 3.6 mW/g mean unspecified whole body -

Exposure 3

Main characteristics
Frequency 1.3 GHz
Type
Waveform
Charakteristic
  • guided field
Polarization
  • circular
Exposure duration repeated daily exposure, 3 h/day, 5 days a week for six to nine weeks
Modulation
Modulation type pulsed
Pulse width 1 µs
Packets per second 600
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 6.7 mW/g mean unspecified whole body -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

At 1.5 mW/g, the levels of cued operant responding by control and exposed rats were comparable, and showed similar progressive diminutions over the course of each daily session. Noncued operant responding was more variable, but again comparable, with both groups of animals showing similar, progressive declines in rate of responding during each session.
At 3.6 mW/g, no specific effects on cued operant response rates were observed. However, there was an initial and transient increase in the rate of extinction of noncued responding.
At 6.7 mW/g, cued response rates were slightly reduced, whereas there was a major decrease in noncued operant responding followed by a sharp rebound during the first post-microwave irradiation week. This marked reduction in noncued operant responding at microwave irradiation onset was in contrast to the relative stability and persistence of FR (fixed-ratio) responding for food reinforcement.

Study character:

Study funded by