Transcranial direct current stimulation ameliorates motor and cognitive functions by regulating neuronal excitotoxicity in experimental Parkinson’s disease model

Purpose: In the study, the therapeutic effects of early and long-term transcranial direct current stimulation (tDCS) in Parkinson's disease (PD) rats with 6-hydroxydopamine (6-OHDA) lesions of tDCS were investigated. Materials and Methods: After early and prolonged tDCS administration in PD animals (starting 24 hours after PD lesion, 1000 mA anodal tDCS, 30 min/day, 13 days), the effects of tDCS on motor and cognitive function behaviors and glutamatergic neuron excitotoxicity were determined by Ca2+, glutamate, and NMDAR1 levels. Results: We found that the 13-day tDCS intervention significantly reduced 6-OHDA-induced motor deficits in locomotor activity, learning, and memory-like behavior. Biochemically, we showed that it also reduces Ca2+, glutamate, and NMDAR1 levels, which cause hippocampal neuronal damage. Conclusion: These results suggest that early and long-term tDCS may exert neuroprotective effects and reduce the exacerbation of motor and cognitive impairments in a rat model of 6-OHDA-induced PD. However, it also shows that tDCS has an effect on the glutamatergic pathway in PD and prevents neuronal excitotoxicity. Furthermore, this preclinical model may increase the potential use of therapeutic tDCS and serve as a translation platform to further define the therapeutic mechanism of tDCS for PD or other disorders.