Weekly treatments with a burst-firing magnetic field alters behavior in the elevated plus maze after two sessions med./bio.

To study the sensitivity of rats to a burst-firing magnetic fields long after administration of a drug (clomipramine) that altered permanently brain chemistry.
Rats exposed to a weak specifically patterned magnetic field for 30 min have shown previously significantly diminished fear conditioning (publication 4797). The authors reasoned that early administration of the antidepressant compound would increase the sensitivity of the rats' maze behavior to this particular pattern of magnetic field stimulation and would require several exposures.

Rats were either injected with clomipramine (15 mg/kg) or saline from postnatal days 8 through 21. When the animals were 90 days of age, they were tested once per week for five weeks in an elevated plus maze. Following each test, rats were exposed (total of 4 exposures) for 30 min. to a burst-firing magnetic field that has been shown to reduce depression in human beings.

• animal
• rat/Wistar albino

After two treatments, the animals exposed to the burst-firing fields (without antidepressant compound treatment) spent about half the amount of time in the open arms of the maze compared to the sham-field exposed rats. The interaction between adult magnetic field treatment and whether the animals had received the antidepressant compound before weaning was not significant statistically.
The findings did not support the authors' hypothesis that early administration of the antidepressant compound increased the sensitivity of the animals' maze behavior. However, the data clearly indicate that at least two weekly sessions may be required before any significant behavioral effects are evident.