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François Giuliano - One of the best experts on this subject based on the ideXlab platform.
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Serotonin 5‐HT2A and 5‐HT5A receptors are expressed by different motoneuron populations in rat Onuf's nucleus
The Journal of comparative neurology, 2007Co-Authors: François Giuliano, Daniel Vergé, X.q. Sun, Marie-jeanne Brisorgueil, Patrick Leclerc, Marie ConrathAbstract:Motoneurons of Onuf's nucleus innervate the pelvic striated Muscles, which play a crucial role in erection, ejaculation, and urinary continence. Serotonergic descending projections from the brain are involved in the modulation of Onuf's motoneuron activity. However, conflicting results regarding the effects of spinal serotonin (5-HT) on pelvi-perineal functions have been reported. They may be partly accounted for by the multiplicity of neuronal targets and receptor subtypes on which 5-HT is acting. In order to provide comparative data regarding 5-HT receptor expression in various groups of Onuf's motoneurons, we used retrograde tracing techniques from different pelvic Muscles combined with immunocytochemistry of 5-HT2A and 5-HT5A receptors in male and female rats. In males, 5-HT2A receptor immunolabeling was very dense in motoneurons innervating the Ischiocavernosus Muscle. By contrast, in female rats, 5-HT2A receptor expression in Onuf's nucleus was very weak. In both genders, 5-HT5A receptor immunoreactivity was found in motoneurons innervating the external urethral sphincter. In males, a moderate or low 5-HT5A immunolabeling was observed in motoneurons innervating the bulbospongiosus and Ischiocavernosus Muscles, respectively. These data show a preferential localization of 5-HT2A and 5-HT5A receptors to motoneurons controlling the striated Muscles located at the penile crus and sphincter Muscles, respectively, suggesting a specific serotoninergic control on different pelvic functions. In addition, the subcellular distribution of receptors suggests a different mode of action of 5-HT, paracrine at 5-HT2A receptors and synaptic at 5-HT5A receptors. This might have implications for pharmacological research targeting different pelvic functions e.g., micturition and ejaculation.
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5-Hydroxytryptamine2C receptors on spinal neurons controlling penile erection in the rat.
Neuroscience, 1999Co-Authors: Mircea Bancila, Daniel Vergé, Olivier Rampin, Jon R. Backstrom, Elaine Sanders-bush, Kevin E. Mckenna, Lesley Marson, André Calas, François GiulianoAbstract:Abstract The localization of 5-hydroxytryptamine 2C receptors in the lumbosacral spinal cord of the rat was investigated using selective antibodies raised against the carboxyl-terminal part of the rat receptor. The distribution of immunoperoxidase labelling at the light microscope level revealed numerous labelled neurons in the gray matter, with a higher intensity in the sacral parasympathetic nucleus, the dorsal gray commissure and particularly the motoneurons of the ventral horn. Confocal microscope analysis showed that immunostaining was mainly intracellular (motoneurons), but could also be associated with the membrane of cell bodies and dendrites. Actually, electron microscope immunogold experiments demonstrated an exclusive staining of the cis -Golgi apparatus. Following pseudo-rabies virus transsynaptic retrograde labelling from the corpus cavernosum, labelled neurons were found in the sacral parasympathetic nucleus and the dorsal gray commissure of the L6–S1 segments. All virus-labelled neurons exhibited 5-hydroxytryptamine 2C receptor immunoreactivity. These results indicate that all parasympathetic preganglionic neurons and their related interneurons which contribute to the innervation of cavernosal tissue bear 5-hydroxytryptamine 2C receptors. In the sacral parasympathetic nucleus, most neurons which were retrogradely-labelled from the pelvic ganglion with Fast Blue also showed 5-hydroxytryptamine 2C receptor immunoreactivity. In the ventral horn, motoneurons retrogradely labelled from the Ischiocavernosus Muscle and the bulbospongiosus Muscle, both of which are involved in erection and ejaculation, were also 5-hydroxytryptamine 2C receptor-immunopositive. The supraspinal serotoninergic control of erection at the lumbosacral level therefore appears to be strongly associated with the activation of 5-hydroxytryptamine 2C receptors, consistent with the proerectile properties of 5-hydroxytryptamine 2C agonists.
Kevin Peikert - One of the best experts on this subject based on the ideXlab platform.
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Muscle spindles in the human bulbospongiosus and Ischiocavernosus Muscles
Muscle & Nerve, 2015Co-Authors: Kevin Peikert, Christian Albrecht MayAbstract:Introduction: Muscle spindles are crucial for neuronal regulation of striated Muscles, but their presence and involvement in the superficial perineal Muscles is not known. Methods: Bulbospongiosus and Ischiocavernosus Muscle specimens were obtained from 31 human cadavers. Serial sections were stained with hematoxylin and eosin, Sirius red, antibodies against Podocalyxin, myosin heavy chain isoforms (MyHC-slow tonic, S46; MyHC-2a/2x, A4.74), and neurofilament for the purpose of Muscle spindle screening, counting, and characterization. Results: A low but consistent number of spindles were detected in both Muscles. The Muscles contained few intrafusal fibers, but otherwise showed normal spindle morphology. The extrafusal fibers of both Muscles were small in diameter. Conclusions: The presence of Muscle spindles in bulbospongiosus and Ischiocavernosus Muscles supports physiological models of pelvic floor regulation and may provide a basis for further clinical observations regarding sexual function and micturition. The small number of Muscle spindles points to a minor level of proprioceptive regulation. Muscle Nerve 52: 55–62, 2015
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Muscle spindles in the human bulbospongiosus and Ischiocavernosus Muscles.
Muscle & Nerve, 2015Co-Authors: Kevin PeikertAbstract:INTRODUCTION: Muscle spindles are crucial for neuronal regulation of striated Muscles, but their presence and involvement in the superficial perineal Muscles is not known. METHODS: Bulbospongiosus and Ischiocavernosus Muscle specimens were obtained from 31 human cadavers. Serial sections were stained with hematoxylin and eosin, Sirius red, antibodies against Podocalyxin, myosin heavy chain isoforms (MyHC-slow tonic, S46; MyHC-2a/2x, A4.74), and neurofilament for the purpose of Muscle spindle screening, counting, and characterization. RESULTS: A low but consistent number of spindles were detected in both Muscles. The Muscles contained few intrafusal fibers, but otherwise showed normal spindle morphology. The extrafusal fibers of both Muscles were small in diameter. CONCLUSIONS: The presence of Muscle spindles in bulbospongiosus and Ischiocavernosus Muscles supports physiological models of pelvic floor regulation and may provide a basis for further clinical observations regarding sexual function and micturition. The small number of Muscle spindles points to a minor level of proprioceptive regulation.
Alessandro Vercelli - One of the best experts on this subject based on the ideXlab platform.
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Hormone-Dependent Plasticity of the Motoneurons of the Ischiocavernosus Muscle: An Ultrastructural Study
Advances in experimental medicine and biology, 1991Co-Authors: Cecilia Maria Cracco, Alessandro VercelliAbstract:The motoneurons innervating the perineal Muscles of the rat are located in the lumbosacral spinal cord within the nucleus of Onuf, made up by a dorsolateral column and a dorsomedial one (Schroeder, 1980).
A. Shafik - One of the best experts on this subject based on the ideXlab platform.
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The vesicocavernosus reflex: Role in the act of micturition
International Urogynecology Journal, 1993Co-Authors: A. ShafikAbstract:The paper studies the action and clinical significance of a reflex termed ‘vesicocavernosus’ in 24 healthy volunteers (mean age 44.6 years, 15 men and 9 women). A balloon-tipped catheter was introduced into the urinary bladder and inflated with air in increments of 50 ml up to 300 ml. The response of the two cavernosus Muscles to rapid vesical inflation and deflation, as well as to interruption and termination of micturition, was displayed on an EMG apparatus. The Muscles contracted upon rapid vesical inflation or deflation, and upon the interruption or termination of micturition. These results were reproducible. In the male, bulbocavernosus Muscle contraction seems to compress and expel the urine into the bulbous urethra. Ischiocavernosus Muscle contraction helps to elevate the penile shaft. The role of the cavernosus Muscles at micturition in women is unknown. The vesicocavernosus reflex could be of diagnostic significance in neurologic conditions.
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The cervicocavernosus reflex: Description of the reflex and its role in the sexual act
International Urogynecology Journal, 1993Co-Authors: A. ShafikAbstract:The paper studies the action and clinical significance of a reflex termed the ‘cervicocavernosus’ reflex. Twenty-two healthy women (mean age 39.7±10.2 SD years) entered the study. The cervix uteri was stimulated both mechanically and electrically by a needle electrode. The response of the bulbo- and Ischiocavernosus Muscles was recorded by a needle electrode inserted in each Muscle. In 10 subjects, the cervix was anesthetized and the cavernosus Muscles' response to stimulation of the anesthetized cervix was recorded. The vaginal pressure was measured at rest and on cervical stimulation by means of a balloontipped catheter introduced into the vagina. The mean vaginal pressure at rest was 5.2±1.8 SD cmH_2O and on cervical stimulation 38.8±10.6 cmH_2O. The cavernosus Muscles showed no resting activity. Upon cervical stimulation, the Muscles contracted with a mean amplitude of 286.4±55.6 SD μ V for the bulbocavernosus Muscle and 176.6±48.8 μ V for the Ischiocavernosus Muscle; the mean latency of the reflex response was 59.2 ±10.6 SD ms. Stimulation of the anesthetized cervix did not evoke contraction of the Muscles. The cervicocavernosus reflex could play a role in enhancing both clitoral and penile erection during the sexual act.
Christian Albrecht May - One of the best experts on this subject based on the ideXlab platform.
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Muscle spindles in the human bulbospongiosus and Ischiocavernosus Muscles
Muscle & Nerve, 2015Co-Authors: Kevin Peikert, Christian Albrecht MayAbstract:Introduction: Muscle spindles are crucial for neuronal regulation of striated Muscles, but their presence and involvement in the superficial perineal Muscles is not known. Methods: Bulbospongiosus and Ischiocavernosus Muscle specimens were obtained from 31 human cadavers. Serial sections were stained with hematoxylin and eosin, Sirius red, antibodies against Podocalyxin, myosin heavy chain isoforms (MyHC-slow tonic, S46; MyHC-2a/2x, A4.74), and neurofilament for the purpose of Muscle spindle screening, counting, and characterization. Results: A low but consistent number of spindles were detected in both Muscles. The Muscles contained few intrafusal fibers, but otherwise showed normal spindle morphology. The extrafusal fibers of both Muscles were small in diameter. Conclusions: The presence of Muscle spindles in bulbospongiosus and Ischiocavernosus Muscles supports physiological models of pelvic floor regulation and may provide a basis for further clinical observations regarding sexual function and micturition. The small number of Muscle spindles points to a minor level of proprioceptive regulation. Muscle Nerve 52: 55–62, 2015
