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Dávila-Santacruz S, Corona-Quintanilla DL, Velázquez-Orozco V, Martínez-Gómez M, Castelán F, Cuevas-Romero E, Barrales-Fuentes B, Nicolás-Toledo L, Rodríguez-Antolín J. Sucrose consumption modifies the urethrogenital reflex and histological organization of the bulbospongiosus muscle in the male rat. Physiol Behav 2024; 273:114391. [PMID: 37907190 DOI: 10.1016/j.physbeh.2023.114391] [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: 07/30/2023] [Revised: 10/06/2023] [Accepted: 10/28/2023] [Indexed: 11/02/2023]
Abstract
Disorders of the bulbospongiosus muscle (Bsm) are associated with male sexual dysfunction, such as premature ejaculation. We determined the effect of sucrose-water consumption during pregnancy-lactation and postnatal on reflex responses and morphology of Bsm fibers in adult male Wistar rat offspring. Female rats were mated and grouped into consumed tap water mothers and sucrose-water (5 %) mothers during pregnancy-lactation to obtain experimental groups. Male pups were weaned and assigned into four groups (n = 12; each group). Those from control mothers who continued drinking tap water (CM-CO group) or sucrose water (CM-SO group), and those from sucrose mothers who drank tap water (SM-CO group) or continued drinking sucrose water (SM-SO group) until adult life. In male rat offspring (n = 6 per group) was recorded the electrical activity of Bsm was recorded during penile stimulation and urethrogenital reflex (UGR). Other male rat offspring were designated for histological analysis (n = 6 per group). Sucrose consumption during prenatal stages increased the frequency of the Bsm during UGR, while pre and postnatal consumption modified muscle fiber cross-sectional area and increased the collagen content, suggesting that a combination of a diet with pre- and postnatal sucrose changes the Bsm morphophysiology possibly causing male sexual dysfunctions.
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Affiliation(s)
| | | | - Verónica Velázquez-Orozco
- Doctorado en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Mexico; Licenciatura en Química Clínica, Facultad de Ciencias de la Salud, Universidad Autónoma de Tlaxcala
| | - Margarita Martínez-Gómez
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90070 Mexico; Instituto de Investigaciones Biomédicas, Departamento de Biología Celular y Fisiología, Universidad Nacional Autónoma de México, Tlaxcala, Mexico
| | - Francisco Castelán
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90070 Mexico; Instituto de Investigaciones Biomédicas, Departamento de Biología Celular y Fisiología, Universidad Nacional Autónoma de México, Tlaxcala, Mexico
| | - Estela Cuevas-Romero
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90070 Mexico
| | | | - Leticia Nicolás-Toledo
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90070 Mexico
| | - Jorge Rodríguez-Antolín
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, 90070 Mexico.
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Uta D, Kiyohara K, Nagaoka Y, Kino Y, Fujita T. Developing a Novel Method for the Analysis of Spinal Cord-Penile Neurotransmission Mechanisms. Int J Mol Sci 2023; 24:ijms24021434. [PMID: 36674942 PMCID: PMC9861114 DOI: 10.3390/ijms24021434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
Sexual dysfunction can be caused by impaired neurotransmission from the peripheral to the central nervous system. Therefore, it is important to evaluate the input of sensory information from the peripheral genital area and investigate the control mechanisms in the spinal cord to clarify the pathological basis of sensory abnormalities in the genital area. However, an in vivo evaluation system for the spinal cord-penile neurotransmission mechanism has not yet been developed. Here, urethane-anesthetized rats were used to evaluate neuronal firing induced by innocuous or nociceptive stimulation of the penis using extracellular recording or patch-clamp techniques in the lumbosacral spinal dorsal horn and electrophysiological evaluation in the peripheral pelvic nerves. As a result, innocuous and nociceptive stimuli-evoked neuronal firing was successfully recorded in the deep and superficial spinal dorsal horns, respectively. The innocuous stimuli-evoked nerve firing was also recorded in the pelvic nerve. These firings were suppressed by lidocaine. To the best of our knowledge, this is the first report of a successful quantitative evaluation of penile stimuli-evoked neuronal firing. This method is not only useful for analyzing the pathological basis of spinal cord-penile neurotransmission in sexual dysfunction but also provides a useful evaluation system in the search for new treatments.
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Affiliation(s)
- Daisuke Uta
- Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
- Correspondence: ; Tel.: +81-76-434-7513
| | - Kazuhiro Kiyohara
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan
| | - Yuuya Nagaoka
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan
| | - Yurika Kino
- Digital Transformation Department, Mitsubishi Tanabe Pharma Corporation, Tokyo 100-8205, Japan
| | - Takuya Fujita
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan
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3
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Kiyohara K, Uta D, Nagaoka Y, Kino Y, Nonaka H, Ninomiya-Baba M, Fujita T. Involvement of Histamine H 3 Receptor Agonism in Premature Ejaculation Found by Studies in Rats. Int J Mol Sci 2022; 23:ijms23042291. [PMID: 35216402 PMCID: PMC8878335 DOI: 10.3390/ijms23042291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
Several of the drugs currently available for the treatment of premature ejaculation (PE) (e.g., local anesthetics or antidepressants) are associated with numerous safety concerns and exhibit weak efficacy. To date, no therapeutics for PE have been approved in the United States, highlighting the need to develop novel agents with sufficient efficacy and fewer side effects. In this study, we focused on the histamine H3 receptor (H3R) as a potential target for the treatment of PE and evaluated the effects of imetit (an H3R/H4R agonist), ciproxifan (an H3R antagonist), and JNJ-7777120 (an H4R antagonist) in vivo. Our in vivo electrophysiological experiments revealed that imetit reduced mechanical stimuli-evoked neuronal firing in anesthetized rats. This effect was inhibited by ciproxifan but not by JNJ-7777120. Subsequently, we evaluated the effect of imetit using a copulatory behavior test to assess ejaculation latency (EL) in rats. Imetit prolonged EL, although this effect was inhibited by ciproxifan. These findings indicate that H3R stimulation suppresses mechanical stimuli-evoked neuronal firing in the spinal-penile neurotransmission system, thereby resulting in prolonged EL. To our knowledge, this is the first report to describe the relationship between H3R and PE. Thus, H3R agonists may represent a novel treatment option for PE.
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Affiliation(s)
- Kazuhiro Kiyohara
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan; (Y.N.); (H.N.); (M.N.-B.); (T.F.)
- Correspondence: (K.K.); (D.U.); Tel.: +81-70-2447-2763 (K.K.); +81-76-434-7513 (D.U.)
| | - Daisuke Uta
- Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
- Correspondence: (K.K.); (D.U.); Tel.: +81-70-2447-2763 (K.K.); +81-76-434-7513 (D.U.)
| | - Yuuya Nagaoka
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan; (Y.N.); (H.N.); (M.N.-B.); (T.F.)
| | - Yurika Kino
- Digital Transformation Department, Mitsubishi Tanabe Pharma Corporation, Tokyo 100-8205, Japan;
| | - Hideki Nonaka
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan; (Y.N.); (H.N.); (M.N.-B.); (T.F.)
| | - Midori Ninomiya-Baba
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan; (Y.N.); (H.N.); (M.N.-B.); (T.F.)
| | - Takuya Fujita
- Research Unit/Neuroscience, Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama 227-0033, Japan; (Y.N.); (H.N.); (M.N.-B.); (T.F.)
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4
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Wiggins JW, Sledd JE, Coolen LM. Spinal Cord Injury Causes Reduction of Galanin and Gastrin Releasing Peptide mRNA Expression in the Spinal Ejaculation Generator of Male Rats. Front Neurol 2021; 12:670536. [PMID: 34239493 PMCID: PMC8258150 DOI: 10.3389/fneur.2021.670536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/21/2021] [Indexed: 01/23/2023] Open
Abstract
Spinal cord injury (SCI) in men is commonly associated with sexual dysfunction, including anejaculation, and chronic mid-thoracic contusion injury in male rats also impairs ejaculatory reflexes. Ejaculation is controlled by a spinal ejaculation generator consisting of a population of lumbar spinothalamic (LSt) neurons that control ejaculation through release of four neuropeptides including galanin and gastrin releasing peptide (GRP) onto lumbar and sacral autonomic and motor nuclei. It was recently demonstrated that spinal contusion injury in male rats caused reduction of GRP-immunoreactivity, but not galanin-immunoreactivity in LSt cells, indicative of reduced GRP peptide levels, but inconclusive results for galanin. The current study further tests the hypothesis that contusion injury causes a disruption of GRP and galanin mRNA in LSt cells. Male rats received mid-thoracic contusion injury and galanin and GRP mRNA were visualized 8 weeks later in the lumbar spinal cord using fluorescent in situ hybridization. Spinal cord injury significantly reduced GRP and galanin mRNA in LSt cells. Galanin expression was higher in LSt cells compared to GRP. However, expression of the two transcripts were positively correlated in LSt cells in both sham and SCI animals, suggesting that expression for the two neuropeptides may be co-regulated. Immunofluorescent visualization of galanin and GRP peptides demonstrated a significant reduction in GRP-immunoreactivity, but not galanin in LSt cells, confirming the previous observations. In conclusion, SCI reduced GRP and galanin expression in LSt cells with an apparent greater impact on GRP peptide levels. GRP and galanin are both essential for triggering ejaculation and thus such reduction may contribute to ejaculatory dysfunction following SCI in rats.
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Affiliation(s)
- James W Wiggins
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States.,Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jonathan E Sledd
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States
| | - Lique M Coolen
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States.,Department of Biological Sciences, Kent State University, Kent, OH, United States
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5
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Wiggins JW, Kozyrev N, Sledd JE, Wilson GG, Coolen LM. Chronic Spinal Cord Injury Reduces Gastrin-Releasing Peptide in the Spinal Ejaculation Generator in Male Rats. J Neurotrauma 2019; 36:3378-3393. [PMID: 31111794 DOI: 10.1089/neu.2019.6509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Spinal cord injury (SCI) causes sexual dysfunction, including anejaculation in men. Likewise, chronic mid-thoracic contusion injury impairs ejaculatory reflexes in male rats. Ejaculation is controlled by a spinal ejaculation generator (SEG) comprised of a population of lumbar spinothalamic (LSt) neurons. LSt neurons co-express four neuropeptides, including gastrin-releasing peptide (GRP) and galanin and control ejaculation via release of these peptides in lumbar and sacral autonomic and motor nuclei. Here, we tested the hypothesis that contusion injury causes a disruption of the neuropeptides that are expressed in LSt cell bodies and axon terminals, thereby causing ejaculatory dysfunction. Male Sprague Dawley rats received contusion or sham surgery at spinal levels T6-7. Five to six weeks later, animals were perfused and spinal cords were immunoprocessed for galanin and GRP. Results showed that numbers of cells immunoreactive for galanin were not altered by SCI, suggesting that LSt cells are not ablated by SCI. In contrast, GRP immunoreactivity was decreased in LSt cells following SCI, evidenced by fewer GRP and galanin/GRP dual labeled cells. However, SCI did not affect efferent connections of LSt, cells as axon terminals containing galanin or GRP in contact with autonomic cells were not reduced following SCI. Finally, no changes in testosterone plasma levels or androgen receptor expression were noted after SCI. In conclusion, chronic contusion injury decreased immunoreactivity for GRP in LSt cell soma, but did not affect LSt neurons per se or LSt connections within the SEG. Since GRP is essential for triggering ejaculation, such loss may contribute to ejaculatory dysfunction following SCI.
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Affiliation(s)
- J Walker Wiggins
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi.,Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, Mississippi
| | - Natalie Kozyrev
- Robarts Institute, Western University, London, Ontario, Canada
| | - Jonathan E Sledd
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - George G Wilson
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - Lique M Coolen
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi.,Department of Biological Sciences, Kent State University, Kent, Ohio
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Teplitsky S, Murphy A, Shenot PJ. Knowledge Gaps in Urologic Care of Female Spinal Cord Injury Patients. Curr Urol Rep 2019; 20:21. [PMID: 30904966 DOI: 10.1007/s11934-019-0884-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE OF REVIEW We highlight the substantial gaps in knowledge on urologic care of female spinal cord injury (SCI) patients. RECENT FINDINGS Males account for approximately 80% of people living with SCI in developed nations. Although there is a robust body of literature in some aspects of urologic care of individuals with SCI, such as treatments for neurogenic detrusor overactivity, there are relatively few studies focusing specifically on females. There are also few studies focusing on other aspects of urologic care of women with SCI such as sexual dysfunction, pelvic organ prolapse, and bladder cancer. Established guidelines for bladder management exist, generally recommending intermittent catheterization, but the fact remains that a substantial number of women with SCI utilize indwelling catheters for bladder management. There remains a paucity of literature using patient-reported measures regarding both outcomes and experiences of urologic management in the SCI population. Bladder management is challenging for many women with SCI. There are few studies on other urologic concerns in women with SCI.
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Affiliation(s)
- Seth Teplitsky
- Department of Urology, Sidney Kimmel Medical College, Thomas Jefferson University, 1025 Walnut St, Ste 1100, Philadelphia, PA, 19107, USA
| | - Alana Murphy
- Department of Urology, Sidney Kimmel Medical College, Thomas Jefferson University, 1025 Walnut St, Ste 1100, Philadelphia, PA, 19107, USA
| | - Patrick J Shenot
- Department of Urology, Sidney Kimmel Medical College, Thomas Jefferson University, 1025 Walnut St, Ste 1100, Philadelphia, PA, 19107, USA.
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7
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Alexander MS, Marson L. The neurologic control of arousal and orgasm with specific attention to spinal cord lesions: Integrating preclinical and clinical sciences. Auton Neurosci 2018; 209:90-99. [DOI: 10.1016/j.autneu.2017.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/09/2016] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
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8
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Courtois F, Alexander M, McLain AB(J. Women's Sexual Health and Reproductive Function After SCI. Top Spinal Cord Inj Rehabil 2017; 23:20-30. [PMID: 29339874 PMCID: PMC5340506 DOI: 10.1310/sci2301-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sexual function and to a lesser extent reproduction are often disrupted in women with spinal cord injuries (SCI), who must be educated to better understand their sexual and reproductive health. Women with SCI are sexually active; they can use psychogenic or reflexogenic stimulation to obtain sexual pleasure and orgasm. Treatment should consider a holistic approach using autonomic standards to describe remaining sexual function and to assess both genital function and psychosocial factors. Assessment of genital function should include thoracolumbar dermatomes, vulvar sensitivity (touch, pressure, vibration), and sacral reflexes. Self-exploration should include not only clitoral stimulation, but also stimulation of the vagina (G spot), cervix, and nipples conveyed by different innervation sources. Treatments may consider PDE5 inhibitors and flibanserin on an individual basis, and secondary consequences of SCI should address concerns with spasticity, pain, incontinence, and side effects of medications. Psychosocial issues must be addressed as possible contributors to sexual dysfunctions (eg, lower self-esteem, past sexual history, depression, dating habits). Pregnancy is possible for women with SCI; younger age at the time of injury and at the time of pregnancy being significant predictors of successful pregnancy, along with marital status, motor score, mobility, and occupational scores. Pregnancy may decrease the level of functioning (eg, self-care, ambulation, upper-extremity tasks), may involve complications (eg, decubitus ulcers, weight gain, urological complications), and must be monitored for postural hypotension and autonomic dysreflexia. Taking into consideration the physical and psychosocial determinants of sexuality and childbearing allows women with SCI to achieve positive sexual and reproductive health.
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Affiliation(s)
- Frédérique Courtois
- Departement of Sexology, Université du Québec à Montréal, Montreal, Canada
- Institut de réadaptation Gingras Lindsay de Montréal, Montreal, Canada
| | - Marcalee Alexander
- Department of Rehabilitative Medicine, Birmingham VA Medical Center, Birmingham, Alabama
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham
- Department of Physical Medicine and Rehabilitation, Harvard School of Medicine, Boston, Massachusetts
| | - Amie B. (Jackson) McLain
- Department of Physical Medicine and Rehabilitation, University of Alabama School of Medicine, Birmingham, Alabama
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9
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Courtois F, Charvier K. Sexual dysfunction in patients with spinal cord lesions. HANDBOOK OF CLINICAL NEUROLOGY 2015; 130:225-45. [PMID: 26003247 DOI: 10.1016/b978-0-444-63247-0.00013-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Many aspects of sexuality can be disrupted following a spinal cord lesion (SCL). It can alter an individual's self-esteem and body image, interfere with positioning and mobility, introduce unexpected problems with incontinence and spasticity, decrease pleasure, and delay orgasm. Sexual concerns in men can involve erectile function, essential for intercourse, ejaculation function, necessary for fertility, and the ability to reach orgasm. In women they can involve concerns with vaginal lubrication, genital congestion, and vaginal infections, which can all go unnoticed, and orgasm, which may be lost. All of these concerns must be addressed during rehabilitation as individuals with SCL continue to live an active sexual life, and consider sexuality among their top priority for quality of life. This chapter describes the impact of SCL on various phases of men's and women's sexual responses and on various aspects of sexuality. Treatments are described in terms of what is currently available and what is specific to the SCL population. New approaches in particular for women are described, along with tips from sexual counseling which consider an overall approach, taking into account the primary, secondary, and tertiary consequences of the SCL on the individual's sexuality. Throughout the chapter, attempts are made to integrate neurophysiologic knowledge, findings from the literature on SCL, and clinical experience in sexual rehabilitation.
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Affiliation(s)
- Frédérique Courtois
- Department of Sexology, Université du Québec à Montréal, Montreal, Quebec, Canada.
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10
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Premature ejaculation associated with lumbosacral lesions. Spinal Cord 2014; 52:905-10. [DOI: 10.1038/sc.2014.175] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 07/31/2014] [Accepted: 08/29/2014] [Indexed: 01/23/2023]
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Abstract
Ejaculatory dysfunction may occur after many different disorders ranging from traumatic spinal cord injury to diabetes mellitus. With an understanding of the many facets and nuances of the ejaculatory apparatus, both anatomic and neurologic, the well-versed clinician can proceed along a safe, efficient, and appropriate treatment algorithm to help affected men and their partners achieve parenthood.
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Affiliation(s)
- Elizabeth Phillips
- Division of Urology, Boston University School of Medicine, Shapiro Center, Suite 3B, 715 Albany Street, Boston, MA 02118, USA
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12
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Chadha HK, Armstrong JE, Mower GD, Hubscher CH. Effects of surgical induction of endometriosis on response properties of preoptic area neurons in rats. Brain Res 2008; 1246:101-10. [PMID: 18955036 DOI: 10.1016/j.brainres.2008.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 09/22/2008] [Accepted: 10/02/2008] [Indexed: 10/24/2022]
Abstract
Subfertility and severe pelvic pains are symptoms associated with endometriosis (ENDO), a common condition among women that is characterized by the growth of the uterine endometrium on the surface of organs within the pelvic region and abdominal cavity. The contribution of the CNS to symptoms associated with ENDO is not known. In the present study, the preoptic area (POA) of the hypothalamus was investigated, as this region of the forebrain is known to play an important role in the neuroendocrine control of the reproductive cycle, mating behavior, and antinociception. Female rats were either induced for ENDO by autotransplantation of uterine tissue (n=20) or uterine fat for surgical sham controls (n=11). Terminal extracellular electrophysiological recordings (urethane anesthesia) were conducted in the POA six weeks post-ENDO induction when the rats were in either the proestrus or metestrus stages of their estrous cycle. Significant differences were found between the ENDO versus SHAM groups of animals for the proportion of inhibitory responses as well as the percentage of neurons responding to stimulation of the abdominal branches of the vagus, which innervates portions of the female reproductive tract, including the ovaries. The endometriotic cysts were found to be significantly larger in proestrus rats (stage when hormones are elevated). These data demonstrate that the responses of POA neurons are influenced by the presence of endometriotic cysts in the abdominal cavity. Since the POA is known to be part of the neural circuitries that mediate nociception and fertility, any deviation from its normal activity under ENDO conditions could contribute to the constellation of symptoms that ensue.
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Affiliation(s)
- Harpreet K Chadha
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
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13
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Carro-Juárez M, Rodríguez-Manzo G. The spinal pattern generator for ejaculation. ACTA ACUST UNITED AC 2008; 58:106-20. [PMID: 18241924 DOI: 10.1016/j.brainresrev.2007.12.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 11/14/2007] [Accepted: 12/05/2007] [Indexed: 01/08/2023]
Affiliation(s)
- Miguel Carro-Juárez
- Laboratorio de Comportamiento Reproductivo, Escuela de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tlaxcala, C.P.90000, Tlaxcala, México.
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14
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Detloff MR, Fisher LC, McGaughy V, Longbrake EE, Popovich PG, Basso DM. Remote activation of microglia and pro-inflammatory cytokines predict the onset and severity of below-level neuropathic pain after spinal cord injury in rats. Exp Neurol 2008; 212:337-47. [PMID: 18511041 DOI: 10.1016/j.expneurol.2008.04.009] [Citation(s) in RCA: 203] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2007] [Revised: 03/19/2008] [Accepted: 04/08/2008] [Indexed: 12/29/2022]
Abstract
Spinal cord injury (SCI) impairs sensory systems causing chronic allodynia. Mechanisms underlying neuropathic pain have been more extensively studied following peripheral nerve injury (PNI) than after central trauma. Microglial activation, pro-inflammatory cytokine production and activation of p38 MAP kinase pathways may induce at-level allodynia following PNI. We investigated whether midthoracic SCI elicits similar behavioral and cellular responses below the level of injury (lumbar spinal cord; L5). Importantly, we show that anatomical connections between L5 and supraspinal centers remain intact after moderate SCI allowing direct comparison to a well-established model of peripheral nerve injury. We found that SCI elicits below-level allodynia of similar magnitude to at-level pain caused by a peripheral nerve injury. Moreover, the presence of robust microglial activation in L5 cord predicted allodynia in 86% of rats. Also increased phosphorylation of p38 MAP kinase occurred in the L5 dorsal horn of allodynic rats. For below-level allodynia after SCI, TNF-alpha and IL-1beta increased in the L5 dorsal horn by 7 dpo and returned to baseline by 35 dpo. Interestingly, IL-6 remains at normal levels early after SCI and increases at chronic time points. Increased levels of pro-inflammatory cytokines also occurred in the thalamus after SCI-induced allodynia. These data suggest that remote microglial activation is pivotal in the development and maintenance of below-level allodynia after SCI. Fractalkine, a known activator of microglia, and astrocytes were not primary modulators of below-level pain. Although the mechanisms of remote microglial activation are unknown, this response may be a viable target for limiting or preventing neuropathic pain after SCI in humans.
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Affiliation(s)
- Megan Ryan Detloff
- Center for Brain and Spinal Cord Repair, Neuroscience Graduate Studies Program, The Ohio State University 43210, USA
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15
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Cothron KJ, Massey JM, Onifer SM, Hubscher CH. Identification of penile inputs to the rat gracile nucleus. Am J Physiol Regul Integr Comp Physiol 2008; 294:R1015-23. [PMID: 18171689 DOI: 10.1152/ajpregu.00656.2007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neurons in the medullary reticular formation (MRF) of the rat receive a vast array of urogenital inputs. Using select acute and chronic spinal cord lesions to identify the location of the ascending neural circuitries providing either direct or indirect inputs to MRF from the penis, our previous studies demonstrated that the dorsal columns and dorsal half of the lateral funiculus convey low- and high-threshold inputs, respectively. In the present study, the gracile nucleus was targeted as one of the likely sources of low-threshold information from the penis to MRF. Both electrophysiological recordings and neuroanatomical tracing [injection of cholera toxin B subunit (CTB) into a dorsal nerve of the penis] were used. After discrimination of a single neuron responding to penile stimulation, testing for somatovisceral convergence was done (mechanical stimulation of the distal colon and the skin over the entire hindquarters). In 12 rats, a limited number of neurons (43 in total) responded to penile stimulation. Many of these neurons also responded to scrotal stimulation (53.5%, dorsal and/or ventral scrotum) and/or prepuce stimulation (46.5%). Histological reconstruction of the electrode tracks showed that the majority of neurons responding to penile stimulation were located ventrally within the medial one-third of the gracile nucleus surrounding obex. This location corresponded to sparse innervation by CTB-immunoreactive primary afferent terminals. These results indicate that neurons in the gracile nucleus are likely part of the pathway that provides low-threshold penile inputs to MRF, a region known to play an important role in mating processes.
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Affiliation(s)
- Kyle J Cothron
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA
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Chadha HK, Hubscher CH. Convergence of nociceptive information in the forebrain of female rats: reproductive organ response variations with stage of estrus. Exp Neurol 2007; 210:375-87. [PMID: 18096159 DOI: 10.1016/j.expneurol.2007.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 11/12/2007] [Accepted: 11/13/2007] [Indexed: 11/30/2022]
Abstract
Neurons in the preoptic area (POA) of the hypothalamus and the bed nucleus of stria terminalis (BST) play an important role in the neuroendocrine control of the reproductive cycle, mating behaviors and nociception. Single unit extracellular recordings were performed in the POA and BST region of 20 urethane anesthetized female rats during either the proestrus (elevated levels of estrogen/progesterone) or metestrus (low circulating hormones) stage of the estrous cycle. A total of 118 neurons in the POA and 65 neurons in the BST responded to the search stimuli, bilateral electrical stimulation of the viscerocutaneous branch of the pelvic nerve and/or sensory branch of the pudendal nerve (i.e., dorsal nerve of clitoris). Most of the neurons responding to the electrical search stimuli received a high degree of somatovisceral convergence, including inputs from the abdominal branches of the vagus, cervix, vagina, colon and skin territories on the perineum and trunk. Mean neuronal response thresholds for vaginal and cervical stimulation but not colon distention were significantly higher for animals tested during proestrus. Also, there was a shift in POA and BST neuronal responsiveness towards more inhibition and less excitation during proestrus for a variety of somatovisceral inputs. These data demonstrate that the changes in hormonal status affect the properties of POA and BST neurons, which likely relates not only to the functional importance of these inputs for reproductive behaviors but also for nociceptive processing as well.
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Affiliation(s)
- Harpreet K Chadha
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
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Kaddumi EG, Hubscher CH. Changes in rat brainstem responsiveness to somatovisceral inputs following acute bladder irritation. Exp Neurol 2006; 203:349-57. [PMID: 17010973 DOI: 10.1016/j.expneurol.2006.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 07/14/2006] [Accepted: 08/17/2006] [Indexed: 12/27/2022]
Abstract
A number of clinical studies indicate the coexistence of multiple chronic pelvic diseases and pain syndromes. An association between various conditions related to the pelvic viscera may relate to a high degree of central visceral convergence, which is a requisite for the cross-organ coordination that is necessary for their normal functions. In the present study, a population of neurons receiving a high degree of somatovisceral convergence (those in the medullary reticular formation--MRF) was targeted in order to examine the effect of infusing a chemical irritant into one organ on the responsiveness of convergent inputs from various visceral and somatic regions of the body, using electrophysiological techniques. Acute irritation of the urinary bladder (UB) with 2% acetic acid significantly decreased the percentage of convergent MRF neuronal responses to UB distention and urethral infusion and significantly increased the percentage responding to whole body, mainly due to stimulation of the face. Irritation also produced a significant increase in the response duration of MRF neurons to distention of colon as well as the bladder (for those few UB responses that still remained). These results indicate that a pelvic/visceral pathology confined to one organ can affect at least some of the convergent responses from other regions of the body. The findings suggest that MRF neurons contribute to the cross-talk between different regions of the body under both normal and pathological conditions.
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Affiliation(s)
- Ezidin G Kaddumi
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
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