Medical/biological study (experimental study)

A magnetic field effect on learning in male golden hamsters med./bio.

By: Lopuch S

Published in: Behav Processes 2009; 81 (1): 133-135

Aim of study (acc. to author)

To investigate the influence of repeated exposure to 10, 20, 30 or 40 Hz magnetic fields on the learning behavior of hamsters in a skinner box.

Background/further details

Male hamsters were assigned randomly to an exposure group (n=12) or sham exposure group (n=12).
The behavioural tests in the skinner box were performed on the following day after the last exposure. In the Skinner box the animals learned to press a lever to receive a food reward (unconditioned stimulus), which was associated with the sound of pressing the lever (conditioned stimulus). As a result a conditioned response was created (index of learning).

Endpoint

cognitive/behavioral endpoints: learning: conditioned response

Exposure

- magnetic field
- low frequency
- signals/pulses

Exposure	Parameters
Exposure 1: 10–40 Hz Modulation type: pulsed Exposure duration: 30 min/day on 8 consecutive days	magnetic flux density: 100 mT

Exposure 1

Main characteristics

Frequency	10–40 Hz
Type	magnetic field
Exposure duration	30 min/day on 8 consecutive days
Additional info	10 Hz, 20 Hz, 30 Hz, 40 Hz

Modulation

Modulation type	pulsed
Pulse width	1 ms
Rise time	200 µs

Exposure setup

Exposure source	coil(s)
Setup	coil placed under a polycarbonate container in which the animals were kept
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 mT	-	-	-	-

Exposed system:

animal
golden hamster (Mesocricetus auratus)
whole body

Methods Endpoint/measurement parameters/methodology

cognitive/behavioral endpoints: conditioned response: number of presses of the lever, associated with eating the food tablet; latency of the first response

Investigated system:

investigation on living organism

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The latency of the first response was not affected by exposure to the magnetic fields.
No significant effects on the performance of the task were observed in animals exposed to 10 and 20 Hz magnetic fields.
Exposure significantly improved the learning of the task in animals exposed to 30 and 40 Hz magnetic fields: The exposed animals needed fewer lever pressings to create the conditioned response and learned the task more quickly than sham-exposed animals.
The results indicate that the effects of magnetic fields on the process of learning in animals are dependent on the applied frequencies.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

not stated/no funding

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