Generation of bladder contractions via electrical stimulation of urethral afferent nerves and intra-urethral stimulation

Neurological disease or spinal cord injury (SCI) can eliminate voluntary bladder control. Our long-term mission is to develop neural prostheses for restoration or neuro-rehabilitation of bladder function based on stimulation of afferent neural pathways that take advantage of native spinal neural circuitry. During voiding, urine flow in the urethra activates positive feedback reflexes that augment bladder contraction. This project sought to determine if electrical stimulation of urethral afferents could initiate bladder contractions and to develop a non-invasive method to investigate these responses in humans. In 3 cats, robust bladder contractions were generated by electrical stimulation of the urethral sensory nerves above a threshold bladder volume and at low (<5 Hz) stimulation frequencies. In 3 cats, a urethral catheter with a ring electrode was able to produce and maintain bladder contractions in the proximal and prostatic urethra via intra-urethral electrical stimulation. These results support the feasibility of the catheter-based method to investigate these effects in humans with spinal cord injury.