Physiological effects of transcranial electrical stimulation of the brain in spontaneously hypertensive rat

The present study was to evaluate the physiological effects of transcranial electrical stimulation (1 Hz, 30 volts) of the brain in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. The authors observed and compared changes in the coefficient of variation and two frequency components reflecting cardiac sympathetic and parasympathetic activities and vasomotor sympathetic tone from autoregressive (AR) power spectra of pulse interval (PIV) and systolic blood pressure variabilities (SPV) in three periods, i.e. control, stimulation and recovery. In the authors' results, transcranial electrical stimulated SHR showed a decrease in arterial blood pressure and an increase cardiac parasympathetic tone evaluated by the coefficient of variation and the high frequency power (HF-PIV) of pulse interval variability as compared with those in control. The authors propose that transcranial electrical stimulation of pulse type with surface bipolar electrodes can be used as one of the useful physiological control tool of hypertension.