Electrophysiological Changes of Multi-site Local Field Potentials after Deep Brain Stimulation in the Medial...

Depression is a major global cause of disability, with a portion of cases being treatment-resistant, which has led to the exploration of deep brain stimulation (DBS) as an alternative treatment. Currently, research on DBS in depression has largely focused on the effects of one or two brain regions, but the connections among multiple targets, especially deep brain regions associated with depression, remain poorly understood. Multi-site local field potential (LFP) analysis provides a means to study these connections. In this study, electrodes were implanted into twelve depression - related brain regions. The effects of acute DBS on the brain network on the medial prefrontal cortex (mPFC) were investigated, especially the functional connectivity changes between these targets. Spectral analysis revealed altered power spectral density (PSD) in the mPFC after acute DBS. Additionally, functional connectivity analysis using the imaginary part of coherence (iCOH) showed significant changes between the mPFC and other potential DBS targets, including the lateral habenula (LHb), subthalamic nucleus (STN), medial forebrain bundle (MFB), nucleus accumbens (NAc), and the CA1 region of the hippocampus. These connectivity changes were restricted to the stimulated hemisphere. Based on these results, we further analyzed information flow between sites using the phase slope index (PSI), a directional connectivity measure. This analysis revealed significant changes in information flow between the left mPFC and contralateral depression-related regions following left-sided mPFC DBS. In conclusion, this study provides electrophysiological insights into the acute effects of mPFC DBS on the brain network of depression, which may contribute to the optimization of DBS treatments in depression.