Medical/biological study (experimental study)

Short-term memory in mice is affected by mobile phone radiation med./bio.

By: Ntzouni MP, Stamatakis A, Stylianopoulou F, Margaritis LH

Published in: Pathophysiology 2011; 18 (3): 193-199

Aim of study (acc. to author)

To study whether real mobile phone exposure affects the object recognition memory in mice. The objects consisted of cubes, pyramides and cylinders of different colours.

Background/further details

The object recognition task consists of a habituation session (day 1), a training session (acquisition phase with two identical objects; day 2) and a test session (day 3). Day 3 consists of two trials (one trial with familiar objects and one trial with a familiar and a novel object) and an inter-trial interval (for memory consolidation).
Mice were divided into three groups (8 animals per group: exposed, sham exposed and control) and the object recognition task was performed according to the following three protocols: 1) "acute exposure": mice (45 days old) were exposed to the mobile phone during the habituation, the training and the test sessions, but not during the 10 min inter-trial interval (memory consolidation phase); 2) "chronic exposure-I": the same mice were exposed for 17 days for 90 min/per day starting at postnatal day 55 to the same mobile phone irradiation. The object recognition task was performed at postnatal day 72 with irradiation present only during the inter-trial interval phase; 3) "chronic exposure-II": mice were continuously exposed daily under the same conditions up to postnatal day 86 (total exposure duration: 31 days). One day later the object recognition task test was performed without irradiation.

Endpoint

cognitive/behavioral endpoints: recognition memory

Exposure

- mobile communications
- mobile phone
- digital mobile phone
- GSM

Exposure	Parameters
Exposure 1: 1,800 MHz Exposure duration: 90 min/day for 3 days (acute exposure), 17 days (chronic exposure-I) or 31 days (chronic exposure-II)	electric field strength: 17 V/m average over time (averaged over 6 min) SAR: 0.22 W/kg average over mass (brain)

Exposure 1

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Exposure duration	90 min/day for 3 days (acute exposure), 17 days (chronic exposure-I) or 31 days (chronic exposure-II)

Exposure setup

Exposure source	cellular phone
Chamber	sound proof, air-conditioned room
Setup	8 animals kept in a 267 mm x 207 mm x 140 mm Plexiglas cage placed in a half-open Faraday cage; mobile phone placed under the cage or the ORT (object recognition test) apparatus; radio playing during exposure to simulate human voice during mobile phone use
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	17 V/m	average over time	measured	-	averaged over 6 min
SAR	0.22 W/kg	average over mass	calculated	brain	-

Reference articles

Fragopoulou AF et al. (2010): Cranial and postcranial skeletal variations induced in mouse embryos by mobile phone radiation
Fragopoulou AF et al. (2010): Whole body exposure with GSM 900MHz affects spatial memory in mice

Exposed system:

animal
mouse/C57BL/6J
whole body

Methods Endpoint/measurement parameters/methodology

cognitive/behavioral endpoints: recognition memory: object recognition task (exploration behaviour: touching the object with the nose or directing the nose toward the object; time spent by mice in exploring the familiar and the novel object; video analysis)
body weight

Investigated system:

investigation on living organism

Investigated organ system:

brain/CNS

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

The data revealed a major effect of the "chronic exposure-I" suggesting a possible severe effect of the electromagnetic field on the memory consolidation phase of the recognition memory process. This may imply that the primary electromagnetic field target may be the entorhinal-hippocampal regions which participate in the object recognition.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

University of Athens, Greece

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