NEC Seminar, 24 October 2025
Speaker: Mia Sargusingh
Lab: Hernandez Reynoso Lab
PI: Ana Hernandez Reynoso, PhD
Title: Bladder Function Modulation via Vagus Nerve Stimulation Paired with Voiding
Abstract:
Incomplete spinal cord injury (SCI) disrupts neural communication in the micturition reflex, causing urine retention, overflow incontinence, and high bladder pressure, risking kidney damage. Intermittent catheterization can address some symptoms but may lead to recurrent urinary tract infections and affect quality of life. Thus, restoring bladder function is a top priority, emphasizing the need for alternative approaches to improve bladder drainage.
Vagus nerve stimulation (VNS) promotes neuroplasticity when paired with rehabilitation by promoting the release of neuromodulators such as acetylcholine, aiding in restoring function. This study presents the first attempt to pair VNS with bladder function to alter urodynamic metrics. We hypothesize that pairing VNS with voiding can increase the voiding volume.
To demonstrate feasibility, intact female Sprague Dawley rats (N=4) were trained to tolerate daily soft-cloth restraint and awake transurethral (PE-50 catheter) bladder filling. Bladder pressure (Pves) was continuously monitored during 1-hour filling (12 mL/h) with VNS (30 Hz, 0.8 mA, 100 µs pulse width, 16 pulse trains) upon voiding for two weeks. Awake cystometry (5 mL/h) at baseline and study end quantified urodynamic metrics.
To establish a baseline understanding of bladder dysfunction after SCI, we conducted weekly awake transurethral cystometry for six weeks in female rats following T9 contusion injury. This minimally invasive approach allowed for the longitudinal assessment of voiding and filling function and will help inform when to start VNS delivery for chronic SCI.