Conditions of application of repeated transcranial magnetic stimulation to rats may mask the effects of the treatment.

Rats of sham repeated transcranial magnetic stimulation (rTMS) group, kept in noisy room and transiently immobilized (5 min) for 12 consecutive days, showed similar inhibition of body weight gain, increase in exploratory locomotor activity, and elevation of motor response to apomorphine as rats undergoing magnetic stimulation of the brain, and had only slightly lower response in apomorphine stereotypy. Some of the responses ascribed to antidepressant action of rTMS in animal experiment may be due to environmental conditions, and not alternating magnetic field passing the brain.