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Updated: May 8, 2025
Nerve-sparing Mid-urethral Obstruction NeMO in Female Small Rodents
Published on: April 25, 2017
Transcutaneous Neuromodulation Promotes Functional Regeneration of the External Urethral Sphincter Neural Circuitry
Ricardo Juárez1, José Luis Palacios2, Yolanda Cruz3
1Graduate Program in Brain Research, University of Veracruz, Veracruz, Mexico.
Objective:
This study investigated the effect of transcutaneous electrical stimulation of the dorsal nerve of the clitoris (DNC-TENS) on the functional recovery of the neural circuitry of the external urethral sphincter (EUS) neural circuitry in two models of childbirth trauma in rats: vaginal distension (VD) and injury of the motor branch of the pudendal nerve (MBPN).
Materials And Methods:
In total, 42 Wistar adult female rats were used. Rats underwent sham VD (SH-VD), VD with sham DNC-TENS (VD SH-TENS) or VD with DNC-TENS, bilateral crush of MBPN crush injury (MBPNC) with sham DNC-TENS, or MBPNC with DNC-TENS. Stimulation was delivered to the dorsal region of the clitoral sheath, immediately and on days 2 and 4 after VD or MBPNC. The outcome parameters were EUS electromyograms (EMGs, amplitude and frequency) and cystometrograms (CMGs). Animals were evaluated at seven and 14 days after VD or SH-VD and at day 9 after the nerve crush.
Results:
In SH-VD animals, the EUS EMG activity increased concurrently with bladder contraction. Tonic and bursting responses also were observed. VD significantly impaired EUS and CMG characteristics in the first week postlesion; in the VD SH-TENS group, the bursting EMG response was abolished; the amplitude of tonic activity decreased (p < 0.0001), and the duration of bladder contraction decreased. DNC-TENS facilitated recovery of bursting and tonic EUS EMG activity after VD (p < 0.0001). As with VD, MBPNC abolished EUS bursting activity and decreased (∼80%) tonic activity. TENS significantly improved EMG and CMG parameters.
Conclusions:
VD and MBPNC significantly impair EUS EMG activity. DNC-TENS facilitates functional recovery of the EUS neural circuitry by promoting neuroregeneration and increases bladder compliance. Further studies are required to determine whether DNC-TENS is an effective noninvasive neuromodulation therapy to alleviate or prevent symptoms of stress urinary incontinence associated with childbirth trauma in women.
