Functional mapping with lumbosacral epidural stimulation for restoration of bladder function after spinal cord injury in rats

Study purpose: The overall objective of this functional bladder mapping study is to identify the spinal cord epidural stimulation (scES) configurations (anode/cathode selection, amplitude, frequency, and pulse width) at the lumbosacral level that can promote neural control of bladder storage (capacity) and voiding efficiency after spinal cord injury (SCI).

Data collection: The testing paradigm involves stimulation on the L6-S1 segment of the spinal cord to combinations of frequency (5, 10, 30, 45, 60 Hz) and intensity (50, 75, 100, 150, 300, 500 μA) to determine the most effective parameters for storage and efficient emptying of the bladder and bowel. Endpoints include rectal and distal colon pressure activity, external urethral sphincter electromyography (EUS EMG), external anal sphincter electromyography (EAS EMG), bulbospongiosus electromyography in males (bulbo EMG), bladder pressure changes, voiding and drop patterns, volume of voided fluid, and muscle movement thresholds.

Primary conclusion: The results indicate frequency-dependent effects on bladder capacity, uresis, bowel peristalsis, and sphincter EMG activity at above motor threshold intensities that differed depending upon neurological intactness, with some sex-dependent differences.

Curator's Notes

Experimental Design: Spinal cord epidural stimulation (scES) mapping at L6-S1 was performed to identify parameters for bladder and bowel storage and/or emptying. Using spinally intact and chronic transected rats of both sexes in acute urethane-anesthetized terminal preparations, scES was systematically applied using a modified Specify 5-6-5 (Medtronic) electrode during bladder filling/emptying cycles while recording bladder and colonic/rectal pressures and external urethral and anal sphincter EMG activity

Completeness: This dataset is a part of a larger study.

Subjects & Samples: A total of 20 female and 15 male Wistar rats were targeted for this mapping study. Half the animals (n=10 females, n=8 males) received a complete spinal cord transection at the T9 spinal level (done 6 weeks prior to terminal mapping study), whereas the intact groups (n=10 females, n=7 males) were not exposed to any surgical manipulation prior to terminal mapping procedures.

Primary vs derivative data: Electrophysiology recordings are done using Spike2 software, which contains the setup for all of the channels being recorded (EUS, EAS, bulbo, 2 cm probe, 10 cm probe, leaks, stim marker, keyboard input). The primary data folder is organized by the subject IDs. There is no derivative data folder.

Important notes: This dataset is currently undergoing data registration and will be updated once this process is complete.