Liz Gregory (UBC)

Presenter: Liz Gregory (University of British Columbia)

Title: The brain-heart connection: Neuromodulatory mechanisms of rTMS-induced heart rate variability in major depressive disorder

Abstract:
Heart rate variability (HRV), the variation in time intervals between each heartbeat, reflects the autonomic nervous system control on the heart. Decreased HRV is associated with disease states, including major depressive disorder (MDD), reflecting an impaired ability to autonomically regulate cardiac activity. Repetitive transcranial magnetic stimulation (rTMS), a non-invasive neurostimulation technique that induces trans-synaptic modulation of brain networks, is an effective intervention for MDD. Notably, rTMS is associated with changes in HRV, which may be critical to its antidepressant mechanisms rather than merely an epiphenomenon. It is theorized that rTMS-induced changes in HRV are driven by trans-synaptic modulation of the central autonomic network, a network of cortical and subcortical brain regions involved in autonomic control. Causal effects of rTMS on CAN modulation have not yet been empirically demonstrated, representing a critical knowledge gap.

This talk will focus on potential mechanisms for the link between HRV and rTMS, as well as recent work I have been conducting in my PhD to address this knowledge gap. Specifically, using a concurrent rTMS-fMRI dataset, I examined the relationship between HRV—measured via in-scanner vectorcardiography—and brain activity during rTMS in individuals with MDD. I will present key findings from this work and discuss future directions for understanding the effects of rTMS on brain-heart communication in MDD.