Medical/biological study (experimental study)

Acute exposure to pulsed 2450 MHz microwaves affects water-maze performance of rats med./bio.

By: Wang B, Lai H

Published in: Bioelectromagnetics 2000; 21 (1): 52-56

Aim of study (acc. to author)

The effect of acute microwave exposure on spatial learning and memory functions was studied via the Morris water maze, in which rats learn to locate a submerged platform in a circular pool of opaque water by using cues in the environment.

Endpoint

cognitive/behavioral endpoints: spatial learning and memory functions

Exposure

- microwaves

Exposure	Parameters
Exposure 1: 2.45 GHz Modulation type: pulsed Exposure duration: continuous for 1 h	power density: 20 W/m² spatial average SAR: 1.2 W/kg average over mass (whole body)

Exposure 1

Main characteristics

Frequency	2.45 GHz
Type	electromagnetic field
Polarization	circular
Exposure duration	continuous for 1 h
Additional info	TE11 mode.

Modulation

Modulation type	pulsed
Pulse width	2 µs
Additional info	500 pulses/second

Exposure setup

Exposure source	cylindrical waveguide
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power density	20 W/m²	spatial average	-	-	-
SAR	1.2 W/kg	average over mass	-	whole body	-

Reference articles

Guy AW et al. (1979): Circularly polarized 2450 MHz waveguide system for chronic exposure of small animals to microwaves

Exposed system:

Methods Endpoint/measurement parameters/methodology

cognitive/behavioral endpoints: Morris water maze experiment (time between release in the water to landing on the platform; distance swum; swim speed)

Investigated system:

investigation on living organism

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Microwave-irradiated animals were slower than sham-exposed and cage control animals in learning to locate the platform. However, there was no significant difference in swim speed among the three groups of rats, indicating that the difference in learning was not due to a change in motor functions or motivation. During the probe trial, microwave-irradiated rats spent significantly less time in the quadrant that had contained the platform, and their swim patterns were different from those of the sham-exposed and cage control rats. The latter observation indicates that microwave-exposed animals used a different strategy in learning the location of the platform. These data show that acute exposure to pulsed microwaves caused a deficit in spatial "reference" memory.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

National Institute of Environmental Health Sciences (NIEHS), North Carolina, USA

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