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Zimmerman LL, Mentzelopoulos G, Parrish H, Marcu VI, Luma BD, Becker JB, Bruns TM. Immediate and Long-Term Effects of Tibial Nerve Stimulation on the Sexual Behavior of Female Rats. Neuromodulation 2024; 27:343-352. [PMID: 36609088 DOI: 10.1016/j.neurom.2022.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 01/06/2023]
Abstract
OBJECTIVES There are limited treatment options for female sexual dysfunction (FSD). Percutaneous tibial nerve stimulation (PTNS) has shown improvements in FSD symptoms in neuromodulation clinical studies, but the direct effects on sexual function are not understood. This study evaluated the immediate and long-term effects of PTNS on sexual motivation and receptivity in a rat model of menopausal women. Our primary hypothesis was that long-term PTNS would yield greater changes in sexual behavior than short-term stimulation. MATERIALS AND METHODS In two experiments, after receiving treatment, we placed ovariectomized female rats in an operant chamber in which the female controls access to a male by nose poking. We used five treatment conditions, which were with or without PTNS and no, partial, or full hormone priming. In experiment 1, we rotated rats through each condition twice with behavioral testing immediately following treatment for ten weeks. In experiment 2, we committed rats to one condition for six weeks and tracked sexual behavior over time. We quantified sexual motivation and sexual receptivity with standard measures. RESULTS No primary comparisons were significant in this study. In experiment 1, we observed increased sexual motivation but not receptivity immediately following PTNS with partial hormone priming, as compared with priming without PTNS (linear mixed effect models; initial latency [p = 0.34], inter-interval latency [p = 0.77], nose poke frequency [p = 0.084]; eight rats). In experiment 2, we observed trends of increased sexual receptivity (linear correlation for weekly group means; mounts [p = 0.094 for trendline], intromissions [p = 0.073], lordosis quotient [p = 0.58], percent time spent with a male [p = 0.39], decreased percent time alone [p = 0.024]; four rats per condition), and some sexual motivation metrics (linear correlation for weekly group means; nose pokes per interval [p = 0.050], nose poke frequency [p = 0.039], decreased initial latency [p = 0.11]; four rats per condition) when PTNS was applied long-term with partial hormone priming, as compared with hormone-primed rats without stimulation. CONCLUSIONS PTNS combined with hormone priming shows potential for increasing sexual motivation in the short-term and sexual receptivity in the long-term in rats. Further studies are needed to examine variability in rat behavior and to investigate PTNS as a treatment for FSD in menopausal women.
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Affiliation(s)
- Lauren L Zimmerman
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Georgios Mentzelopoulos
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Hannah Parrish
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Vlad I Marcu
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA; Department of Engineering Physics, University of Michigan, Ann Arbor, MI, USA
| | - Brandon D Luma
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jill B Becker
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA; Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| | - Tim M Bruns
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.
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Sánchez-García O, López-Juárez R, Corona-Quintanilla DL, Ruiz ÁC, Martínez-Gómez M, Cuevas-Romero E, Castelán F. Estrogens influence differentially on the pelvic floor muscles activation at somatovisceral reflexes involved in micturition of rabbits. Menopause 2021; 28:1287-1295. [PMID: 34520412 DOI: 10.1097/gme.0000000000001838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the estrogen-dependency of the bladder and urethral function and the coordinated activation of pelvic floor muscles (PFM) during micturition. METHODS We allocated age-matched female rabbits to control, 1-month ovariectomized (OVX), and OVX plus 2-week estradiol benzoate (EB) groups to record cystometry, urethral pressure, and electromyograms of bulbospongiosus (Bsm), and pubococcygeus muscles (Pcm) simultaneously. We also measured serum estradiol levels and myofiber cross-sectional area. We assessed urodynamic and urethral variables, categorized the Bsm-Pcm activation patterns at storage and voiding phases, and obtained the power spectrum density of muscle activation around the voiding phase. We investigated the influence of ovarian hormones, in general, and the contribution of estrogen, particularly on the functions of the bladder, urethra, and PFM. Statistical significance was set at P < 0.05. RESULTS Ovarian hormones influence the bladder, urethral, and PFM functions. The urodynamics analyses indicated estrogens contribute to voiding duration and, to a lesser extent, to the time between bladder contractions. Urethral pressure at closure (maximal pressure-to-maximal urethral pressure ratio) improved partially (8%, P < 0.05) in the OVX plus 2-week estradiol benzoate compared with OVX, but urethral resistance increased (∼1.9-fold, P < 0.05) compared with control rabbits. Our findings support that Pcm activity at voiding is estrogen-sensitive, albeit EB administration reduced it at storage resume, which relates to high urethral resistance. CONCLUSIONS Ovariectomy impairs bladder and urethral pressures and Bsm and Pcm activation at micturition in anesthetized rabbits. Estrogen administration partially reverts some of these effects and influences Pcm activation.
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Affiliation(s)
- Octavio Sánchez-García
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
- School of Clinical Chemistry, Faculty of Health Sciences, Autonomous University of Tlaxcala, Tlaxcala, Mexico
| | - Rhode López-Juárez
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
- School of Clinical Chemistry, Faculty of Health Sciences, Autonomous University of Tlaxcala, Tlaxcala, Mexico
| | | | - Ángeles Carrasco Ruiz
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
- Faculty of Dentistry, Autonomous University of Tlaxcala, Tlaxcala, Mexico
| | - Margarita Martínez-Gómez
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
- Departament of Cellular Biology and Physiology, Institute for Biomedical Research, National Autonomous University of Mexico, Mexico City, Mexico
| | - Estela Cuevas-Romero
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
| | - Francisco Castelán
- Tlaxcala Center for Biology of Behavior, Autonomous University of Tlaxcala, Zacatelco, Mexico
- Departament of Cellular Biology and Physiology, Institute for Biomedical Research, National Autonomous University of Mexico, Mexico City, Mexico
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