Acute Monitoring of Genitourinary Function Using Intrafascicular Electrodes: Selective Pudendal Nerve Activity Corresponding to Bladder Filling, Bladder Fullness, and Genital Stimulation

ObjectiveTo investigate the use of a microelectrode array with a high spatial density of penetrating intrafascicular electrodes for selective recording of pudendal nerve activity evoked by a variety of genitourinary stimuli.Materials and MethodsFelines were anesthetized with alpha-chloralose and high-density Utah slanted electrode arrays (48 microelectrodes; 200-μm spacing) were implanted into the pudendal nerve for acute experimentation. Neural activity was recorded during bladder filling, spontaneous reflexive distention-evoked bladder contractions, and tactile somatosensory stimulation.ResultsThe intrafascicularly implanted pudendal nerve electrodes were able to selectively record neural activity that corresponded to various genitourinary stimuli. Across all seven experimental animals, a total of 10 microelectrodes recorded neural units that were selectively driven by bladder filling or distention-evoked bladder contractions. Twenty-two electrodes were selectively driven by tactile stimulation.ConclusionMicroelectrode arrays implanted intrafascicularly into the pudendal nerve can be used to selectively record the neural responses that reflect bladder status and urogenital tactile stimulation. This work sets the stage for developing future implantable closed-loop neuroprosthetic devices for restoration of bladder function.