Heart-Brain Coupling

This study focuses on individuals with depressive tendencies and investigates the regulatory effects of Transcranial Magnetic Stimulation (TMS)-guided by personalized functional connectivity mapping-on heart-brain coupling in this population, while also exploring the underlying mechanisms.Participants will undergo 3T functional magnetic resonance imaging (fMRI) scans, followed by four different types of neurostimulation: stimulation targeting individualized Dorsolateral Prefrontal Cortex (DLPFC) -Subgenual Anterior Cingulate Cortex (sgACC) functional connectivity, stimulation targeting individualized DLPFC-insula functional connectivity, standard F3 targeting, and sham stimulation. The order of these stimulation sessions will be randomized. Researchers will simultaneously record the participants' electroencephalogram (EEG) and electrocardiography (ECG) signals before and after stimulation, and will record ECG in real-time during the stimulation. The primary objective of this study is to investigate the effects of DLPFC targeting specificity on metrics such as heart-brain coupling in individuals with depressive tendencies, thereby providing a basis for future research on objective assessment and personalized interventions for depression.

This randomized, sham-controlled mechanistic trial will examine whether a single session of high-frequency repetitive transcranial magnetic stimulation, rTMS, applied to the left dorsolateral prefrontal cortex can modify heart-brain coupling in women with recurrent pregnancy loss and elevated body mass index, BMI. Women with recurrent pregnancy loss often experience reproductive, metabolic, and emotional stress at the same time, and this combined vulnerability may be associated with altered autonomic regulation and exaggerated cardiac responses to stress. The left dorsolateral prefrontal cortex is a key brain region involved in cognitive control, emotion regulation, and top-down modulation of autonomic function. Eligible participants will be randomly assigned in a 1:1 ratio to receive either real or sham rTMS at the same left dorsolateral prefrontal target. The stimulation protocol will use 10 Hz rTMS at 100% motor threshold, delivered in 30 cycles of 5 s stimulation followed by 11 s inter-train interval, with simultaneous 3-lead electrocardiography recording. The primary endpoint will be the between-group difference in mean heart-brain coupling across 30 stimulation cycles. Safety and tolerability will also be monitored. This study is intended to provide mechanistic evidence and methodological support for future multi-session randomized trials in this population.