Cerebellar and Cerebral Cortical Responses to Cathodal tDCS: An in Vivo Approach to Study Its Applicability to Cerebellar Ataxia Treatment

According to recent studies, the use of transcranial direct current stimulation (tDCS) has shown promise as a potential therapy for cerebellar movement disorders. Our previous studies explored the effects of anodal tDCS stimulation on the Purkinje cell firing rate and local field potentials (LFPs) in the cerebellar cortex. The aim of our current study is to investigate the effects of cathodal tDCS stimulation on Purkinje cell firing rates and cerebellar cortical LFPs. From 5 Sprague-Dawley rats, 6 Purkinje cells were isolated in vivo from the cerebellar cortex along with LFP recordings in the cerebellar and cerebral cortices at 100 µA and 200 µA via cathodal stimulation. Power spectrum analysis was conducted to study the general cerebellar cortical activity changes by tDCS. The results revealed an increase in the amplitude at approximately 10 Hz in 2 out of 6 cells. The remaining 4 cells did not show any significant changes. Analysis of the mean frequency was conducted to study the individual Purkinje cell output. Three cells showed a decrease in firing rate following cathodal stimulation, and three cells showed an increase in firing rate following the same stimulation. Further data analysis using cross-correlation and coherence will be done to investigate if these changes are associated with changes in the motor cortex.