Subthalamic Stimulation Inhibits Bladder Contraction by Modulating the Local Field Potential and Catecholamine Level of the Medial Prefrontal Cortex

AIMS: The patients with Parkinson’s disease (PD) present with lower urinary tract symptoms (LUTS), but the efficacy of subthalamic nucleus deep brain stimulation (STN-DBS) on LUTS is unknown. The medial prefrontal cortex (mPFC) is a known higher micturition center which are modulated by STN-DBS. We aim to clarify STN-DBS-related changes in the neuronal activity of the mPFC in terms of bladder contraction, using normal and PD rats. METHODS: Experiments in normal and 6-hydroxydopamine hemi-lesioned PD rats were conducted under urethane anesthesia. STN-DBS was applied to the left STN, with simultaneous monitoring of bladder contractions. The mPFC’s local field potential (LFP) was recorded before, during, and after STN-DBS (n = 6: normal rats, n = 6: PD rats). Before, during and after STN-DBS (n = 5: normal rats, n = 6: PD rats), extracellular fluid was collected from mPFC. RESULTS: STN-DBS significantly increased bladder inter-contraction interval. STN-DBS significantly decreased mPFC alpha power in normal rat and increased alpha power in PD rat. The mPFC levels of levodopa, dopamine, serotonin and their metabolites in PD rats decreased significantly during and after STN-DBS, whereas the serotonin and its metabolites and homovanillic acid (HVA) levels decreased significantly in normal rats following STN-DBS. CONCLUSION: STN-DBS increased intercontraction intervals for the bladder in both normal and PD rats, as assessed by alpha power and catecholamine levels in mPFC, probably due to changes in neural activity. The effect of STN-DBS on mPFC levels of catecholamine differentiated between the normal and PD rats.