[Behavioral and biochemical effects of magnetic brain stimulation and electroshock in rats]

It was proposed that the repetitive rapid-rate transcranial magnetic stimulation (TMS) induces the functional and structural changes analogous to those which are evoked during the electroconvulsive treatment. Presently, we compared the effects of 8 daily treatments with TMS (t = 5 min, B = 0.1 T, trise = 200 microseconds, f = 50 Hz) and electroconvulsive shock (ECS) (t = 0.5 s, I = 150 mA, f = 50 Hz) on the behavior of rats in the forced swimming test (24 h after the last treatment), the exploratory activity test (0-10 min), the basal locomotor activity test (11-30 min), and the tail flick test (2 h after the last treatment). We also tested (24 h after the treatment) the reactivity of the cyclic AMP generating system in cerebral cortical slices. Statistical significance of the results was estimated by ANOVA and t-Student test. The immobility time in the forced swimming test was shortened after TMS and ECS to 86 and 75% of control values, respectively (p < 0.05 and p < 0.01). Both ECS and TMS depressed the basal locomotor activity (by 60 and 80%, resp.), and ECS, but not TMS, diminished also the exploratory activity by 70% (p < 0.01) only ECS induces analgesia, prolonging tail-flick latency by 90% (p < 0.01). ECS diminished the accumulation of the noradrenaline-stimulated cyclic AMP in the cortex slices (by 35%; p < 0.05). The effect after TMS was similar but statistically not significant (87% of control values). The data suggest that TMS produces in rats some responses that are regarded as predictive for the antidepressant activity, similar to those produced by ECS, but less side effects.