The subthalamic activity and striatal monoamine are modulated by subthalamic stimulation

Area of Science:

• Neuroscience
• Parkinson's Disease Research
• Deep Brain Stimulation

Background:

• The precise mechanisms of subthalamic nucleus deep brain stimulation (STN-DBS) in alleviating Parkinson's disease (PD) symptoms remain incompletely understood.
• Striatal monoamine levels and subthalamic beta activity are potential contributors to STN-DBS efficacy, but their direct relationship is unclear.

Purpose of the Study:

• To investigate the correlation between striatal monoamine levels and STN beta activity induced by STN-DBS.
• To differentiate these correlations in normal versus PD model rats.

Main Methods:

• Experiments were conducted on urethane-anesthetized normal and 6-hydroxydopamine-lesioned PD model rats.
• Subthalamic nucleus deep brain stimulation (STN-DBS) was applied, and local field potentials (LFPs) and striatal monoamine levels were measured before, during, and after stimulation.
• Spectral analysis of STN-LFPs and monoamine level measurements were performed.

Main Results:

• In PD model rats, STN-DBS led to decreased 3,4-dihydroxyphenylacetic acid (DOPAC) levels and reduced STN beta power post-stimulation.
• In normal rats, STN beta power increased post-stimulation, with no significant changes in monoamine levels.
• Positive correlations were observed between STN beta power and DOPAC/5-HT in PD model rats, and between dopamine/5-HT in normal rats.

Conclusions:

• STN-DBS can reduce DOPAC levels and alter STN beta power in a PD rat model.
• The relationship between STN beta power and striatal monoamines differs between normal and PD model rats, suggesting distinct neurochemical modulations.