Transcranial electrical stimulation (Limoge's currents) potentiates the inhibition of righting reflex induced by droperidol in rats

The effects of transcranial electrical stimulation (TCES) on droperidol-tre ated rats were evaluated using the righting reflex latency (RRL) test. TCES (high frequency (HF)-166 Wt, intermittent-100 Hz current) delivered throug h three electrodes (a negative electrode placed between the eyebrows and po sitive electrodes located in the retro-mastoid region) was shown to potenti ate the inhibition of righting reflex induced by droperidol. This potentiat ion was found to depend on the dose of the drug, the characteristics of the current delivered and the duration of stimulation. We also observed that T CES-induced potentiation of inhibition of righting reflex produced by drope ridol injection was not reversed: (i) after naltrexone administration, (ii) when measures were performed on p-chlorophenylalanine (pCPA)-treated anima ls. These results suggest that, under the experimental conditions: (i) TCES does not interact with opioid endogenous to potentiate droperidol effects, (ii) the effect of TCES on dopaminergic system prevails against TCES actio n on serotonergic system. Though these findings enlarge the comprehension o f TCES effects on the central nervous system, further investigations are ne cessary to elucidate TCES mechanisms. (C) 1999 Elsevier Science B.V. AU rig hts reserved.