Mirto-Aguilar N, Morán C, Díaz A, Cruz Y. Mapping afferent and pelvic postganglionic neurons of the urethra from female rats: The L6 DRG is the major primary afferent supplier.
Neurourol Urodyn 2021;
40:1880-1888. [PMID:
34420224 DOI:
10.1002/nau.24770]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/19/2021] [Accepted: 07/29/2021] [Indexed: 11/08/2022]
Abstract
AIMS
To map sensory and pelvic postganglionic neurons from three different regions of the female rat urethra.
METHODS
The neuronal tracer True Blue (TB) was injected into the pre-pelvic, pelvic, and clitoral regions of the urethra from female Wistar rats. Seven days after TB injection, TB+ cells from the dorsal root ganglia (DRGs) and the major pelvic ganglion (MPG) were examined. The number and morphometry of TB+ cells were determined.
RESULTS
TB+ cells were mainly distributed in lumbar 1 (L1), lumbar 2 (L2), lumbar 6 (L6), and sacral 1 (S1) DRGs, and in the MPG. The mean number of sensory neurons was 1200 ± 143. TB injection in pre-pelvic and pelvic urethra labeled neurons in L1, L2, L6, and S1 DRGs. TB injection in clitoral urethra labeled neurons in L6 and S1 DRGs. L6 DRG contained >50% of the total urethral TB+ neurons, and ~80% of the clitoral region. The mean value of the total number of MPG TB+ neurons was 1217 ± 72. DRG and MPG neurons projecting to the urethra presented a somatotopic distribution.
CONCLUSIONS
The results demonstrated that L6 DRG is the major supplier of afferent innervation to the urethra, and that the distal urethral region is exclusively innervated by lower lumbosacral DRGs. Considering that electrical stimulation of sensory pudendal nerve improves overactive bladder, and that most of the sensory neurons in the distal urethra are from L6 DRG, electrical stimulation of this ganglion may be an innovative and effective neuromodulation therapy for neurogenic urinary dysfunctions.
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