The present investigation was aimed to answer the following elementary, though important question concerning the sympathetic ganglion: Do the decentralized preganglionic terminals retain their full capacity to develop posttetanic potentiation (PTP) before substantial Wallerian degeneration takes place? Experiments were performed on the cat superior cervical ganglion in situ, and they followed a factorial design. The factors were: tetanization (supramaximal pulses, 0.2 ms, 24 Hz, 30 s), acute decentralization, and moderate hexamethonium blockade (5 mg/kg). Two levels were dealt with, namely, the indicated maneuvers were either performed or not performed. PTP was was measured in the S2 wave and the following variables were studied: decay constant, area under the curve and delay to summit occurrence. The analysis of variance showed that decentralization did not affect the development of PTP. Therefore, the nondegenerated terminals are fully capable of sustaining PTP, without the aid of the preganglionic cell bodies.
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J Physiol
January 2025
Université Paris Cité, CNRS, ENS Paris Saclay, Centre Borelli UMR 9010, Paris, France.
Terminal Schwann cells (TSCs) are capable of regulating acetylcholine (ACh) release at the neuromuscular junction (NMJ). We have identified GABA as a gliotransmitter at mouse NMJs. When ACh activates α7 nicotinic ACh receptor (nAChRs) on TSCs, GABA is released and activates GABA receptors on the nerve terminal that subsequently reduce ACh release.
View Article and Find Full Text PDFPflugers Arch
December 2024
School of Exercise and Nutritional Sciences, College of Health and Human Services, San Diego State University, 5500 Campanile Dr., San Diego, CA, 92182, USA.
The purpose was to investigate the changes in cytosolic Ca and force output during post-tetanic potentiation (PTP) during pre-fatigue and during prolonged low-frequency force depression (PLFFD) following fatigue. Intact single myofibers from the flexor digitorum brevis of mice were electrically stimulated to record force (n = 8) and free cytosolic Ca concentration ([Ca]) with FURA-2 (n = 6) at 32 °C. Initially, force and [Ca] were measured during brief (350 ms) trains of stimuli at 30, 50, 70, and 200 Hz at ~ 2 s intervals (Force-frequency protocol, FFP).
View Article and Find Full Text PDFAdv Mater
December 2024
Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 2, Sant Adriá de Besós, Barcelona, 08930, Spain.
Neuromorphic hardware facilitates rapid and energy-efficient training and operation of neural network models for artificial intelligence. However, existing analog in-memory computing devices, like memristors, continue to face significant challenges that impede their commercialization. These challenges include high variability due to their stochastic nature.
View Article and Find Full Text PDFClin Neurophysiol
December 2024
Nara Medical University, Department of Anesthesiology, Kashihara, Japan. Electronic address:
Global Spine J
November 2024
Department of Orthopaedic Surgery, Nara Medical University, Kashihara, Japan.
Study Design: Prospective within-subjects study.
Objectives: Although motor-evoked potential (MEP) amplitude can reportedly be increased by tetanic stimulation of the peripheral nerves before transcranial electrical stimulation (TES), no reports have described on whether tetanic transcranial stimulation augments the wave amplitudes of spinal cord-evoked potentials (Tc-SCEP). The primary purpose of this study was to investigate whether tetanic stimulation induces waveform amplification of Tc-SCEP.
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