High frequency stimulation of subthalamic nucleus synchronously modulates primary motor cortex and caudate putamen based on dopamine concentration and electrophysiology activities using microelectrode arrays in Parkinson’s disease rats

Abstract

High-frequency stimulation of subthalamic nucleus (STN-HFS) is highly effective in alleviating motor symptoms in Parkinson’s disease (PD). However, there are few reports about the simultaneous changes of neural information, including neurotransmitter signal and neuro-electrophysiological signal (multiple brain regions), under the influence of STN-HFS. Here, a comprehensive system was established, while applying electrostimulation, modified microelectrode arrays were utilized to record dopamine concentration in caudate putamen (CPu) and to detect neuro-electrophysiological signal in primary motor cortex (M1) and CPu synchronously. Results show that rats with PD, dopamine level is significantly lower than that of normal rats; powers of spike trains in M1 and CPu are much higher than these of normal rats in low delta frequency range (0.3–1.5 Hz). Additionally, significant responses to STN-HFS were recorded. After STN-HFS, dopamine level dramatically increased more than 2-fold its pre-HFS; powers of M1 spike and CPu spike were suppressed in ∼1 Hz; Sequentially, neurotransmitter and electrophysiology activities gradually returned to stable, and recovered to PD-state. These observations revealed that the effects of STN-HFS were highly correlated with dopamine and electrophysiology activities in cortex-basal ganglia loop but last a brief duration, a theoretical basis that could be applied in closed-loop STN-HFS for long-term suppression of tremor.