Introduction: It has been hypothesized that lifelong premature ejaculation is part of a biological variation in the intravaginal ejaculation latency, but what causes this variation remains poorly understood.
Aim: The aim of this study is to elucidate whether variations in ejaculation latencies in an experimental rat model for premature ejaculation are linked to differences in the spinal command of ejaculation.
Main Outcome Measures: Electrical microstimulation of the spinal generator for ejaculation revealed an accelerated expulsion phase in rapid ejaculating rats.
Methods: Adult male Wistar rats were categorized as "sluggish,""normal," or "rapid" ejaculators on the basis of their ejaculation frequency in sexual mating tests. One to three weeks after selection, males were urethane anesthetized and electrically microstimulated in the spinal generator for ejaculation, evoking ejaculation. Bulbospongiosus muscle electromyographic and intraluminal vas deferens pressure were measured simultaneously, representing, respectively, the expulsion and emission phase in ejaculation.
Results: Electrical microstimulation of the spinal generator for ejaculation evoked ejaculation in "sluggish" (N = 9), "normal" (N = 13), and "rapid" (N = 11) ejaculating rats. Vas deferens contraction (emission phase) was evoked at different stimulation strengths, but response properties were not statistically different between "sluggish,""normal," and "rapid" ejaculator rats. Bulbospongiosus muscle contractions (expulsion phase) following microstimulation was significantly accelerated in "rapid" rats as compared with "sluggish" and "normal" rats. The total duration of bulbospongiosus muscle contractions remained unchanged between the three ejaculator groups.
Conclusions: Our results provide the first scientific evidence supporting a neurophysiological difference between "rapid,""normal," and "sluggish" ejaculators, expressed as an accelerated expulsion phase in "rapid" ejaculator rats. This bridges the gap between a sexual behavior trait and the spinal command of ejaculation.
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http://dx.doi.org/10.1111/j.1743-6109.2009.01308.x | DOI Listing |
PLoS Comput Biol
January 2025
Biorobotics Laboratory, EPFL, Lausanne, Switzerland.
Humans can perform movements in various physical environments and positions (corresponding to different experienced gravity), requiring the interaction of the musculoskeletal system, the neural system and the external environment. The neural system is itself comprised of several interactive components, from the brain mainly conducting motor planning, to the spinal cord (SC) implementing its own motor control centres through sensory reflexes. Nevertheless, it remains unclear whether similar movements in various environmental dynamics necessitate adapting modulation at the brain level, correcting modulation at the spinal level, or both.
View Article and Find Full Text PDFWorld Neurosurg
January 2025
Department of Orthopedics, General Hospital of Northern Theater Command of Chinese PLA, Shenyang, Liaoning, 110016, China. Electronic address:
Objective: Risk factors for noncontiguous spinal fractures (NSFs), which are important for early, timely diagnoses and treatments of elderly individuals with traumatic spinal fractures, have not been discussed in depth. Thus, this study aimed to investigate the risk factors for noncontiguous spinal fractures (NSFs).
Methods: The records of 1,415 elderly patients (aged 60 years and over) who presented with TSFs between 2013 and 2019 were retrospectively reviewed.
Bioorg Chem
January 2025
Department of Pharmacy, General Hospital of Northern Theater Command, Shenyang 110840, People's Republic of China. Electronic address:
Transient Receptor Potential Ankyrin 1 (TRPA1) is a non-selective cation channel involved in detecting harmful stimuli and endogenous ligands, primarily expressed in sensory neurons. Due to its role in pain and itch, TRPA1 is a potential drug target. We identified an oxindole core structure via high-throughput screening, modified it, and tested the modified compounds in vitro and in vivo.
View Article and Find Full Text PDFJ Orthop Surg Res
December 2024
The First School of Clinical Medicine, Southern Medical University, No.1838 North of Guangzhou Road, Guangzhou, 510515, People's Republic of China.
Background: This study is aimed to compare the differences in clinical outcomes between the crossed rod configuration and the parallel rod configuration applied in posterior occipitocervical and atlantoaxial fixations, and to assess the clinical applicability of crossed rods.
Methods: From January 2015 to December 2021, 21 patients with craniocervical junction disorders were treated surgically with the crossed rod technique (CR group). Meanwhile, 27 corresponding patients treated with the conventional parallel rod technique were included as control (PR group).
Physiol Rev
December 2024
Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, Julius-Maximilians-University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
This review discusses how the nervous system controls the complex body movements keeping animals up and running. In particular, we revisit how research in insects has shed light onto motor control principles that govern movements across the animal kingdom. Starting with the organization and evolution of the insect nervous system, we discuss insights into the neuronal control of behaviors varying in complexity, including escape, flight, crawling, walking, grooming, and courtship.
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