The antidepressant-like effect of tDCS in mice: A behavioral and neurobiological characterization

Background: Transcranial direct current stimulation (tDCS) is a non-invasive method increasingly popular for the treatment of several brain disorders, such as major depression. Despite great enthusiasm and promising results, some studies report discrepant findings and no consensus exists for the clinical use of tDCS.

Objective: The present study aims to (i) determine the most effective stimulation parameters to optimize antidepressant-like effect of tDCS in the forced-swim test in mice and (ii) identify brain regions recruited by tDCS and possibly involved in its behavioral effect using Fos immunohistochemistry.

Results: We reported that tDCS induced long-lasting antidepressant-like effect, which varied as a function of stimulation settings including number, duration, intensity and polarity of stimulation. Interestingly, the present study also demonstrated that tDCS reduced depressive-like behaviors induced by chronic corticosterone exposure. Furthermore, behavioral outcomes induced by a single stimulation were associated with neuronal activation in the prefrontal cortex, dorsal hippocampus, ventral tegmental area and nucleus accumbens, whereas no overexpression of c-fos was associated with 10 stimulations.

Conclusion: The strongest behavioral response was observed with an anodal stimulation of 200 μA during 20min. The repetition of this stimulation was necessary to induce long-lasting behavioral effects that are probably associated with plastic changes in the neuronal response.