Synaptic modulation refers to altered excitability of a synapse by a substance that does not produce a spike potential at the synapse. Available evidence points to the conclusion that beta-melanocyte stimulating hormone (beta-MSH) modulates synaptic transmission through monosynaptic pathways in the cat spinal cord. Earlier evidence is reviewed, and new data are presented. In the first experiments populations of cells contributing to a knee jerk were studied using the Lloyd preparation, and MSH was found to increase the monosynaptic reflex. With intracellular single unit recording techniques, beta-MSH was found to facilitate recovery from synaptic transmission. With extracellular single unit recording techniques and iontophoretic methods for drug application, beta-MSH has been found to increase the probability of generation of single spike potentials by alpha-motoneurons in response to orthodromic stimulation. Administration of beta-MSH did not cause spontaneous discharge of alpha-motoneurons. The physiological and pharmacological importance of synaptic modulation is discussed.
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http://dx.doi.org/10.1016/0306-4530(85)90044-7 | DOI Listing |
J Ethnopharmacol
January 2025
Health Medical Center, Hubei Minzu University, Enshi, Hubei, 445000, PR China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Disease, Hubei Minzu University, Enshi, Hubei, 445000, PR China. Electronic address:
Ethnopharmacological Relevance: Qiangji Decoction (QJD), a Chinese medicine, is widely used in Traditional Chinese Medicine to treat amnesia and Alzheimer's disease (AD), showing significant anti-AD effects. However, the precise mechanisms behind these effects are not well understood and require more research.
Aim Of The Study: This study aims to elucidate the mechanisms by which QJD ameliorates neuronal damage, synaptic dysfunction, and mitochondrial impairment in AD through the regulation of ROCK2/Drp1-mediated mitochondrial dynamics.
J Gen Physiol
March 2025
Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
Voltage-gated Ca2+ channels (VGCCs) are highly expressed throughout numerous biological systems and play critical roles in synaptic transmission, cardiac excitation, and muscle contraction. To perform these various functions, VGCCs are highly regulated. Inactivation comprises a critical mechanism controlling the entry of Ca2+ through these channels and constitutes an important means to regulate cellular excitability, shape action potentials, control intracellular Ca2+ levels, and contribute to long-term potentiation and depression.
View Article and Find Full Text PDFJ Neurosci
January 2025
Carney Institute for Brain Science, Brown University, Providence, RI 02912
The neuromuscular junction (NMJ) is the linchpin of nerve-evoked muscle contraction. Broadly, the function of the NMJ is to transduce nerve action potentials into muscle fiber action potentials (MFAPs). Efficient neuromuscular transmission requires both cholinergic signaling, responsible for generation of endplate potentials (EPPs), and excitation, the amplification of the EPP by postsynaptic voltage-gated sodium channels (Nav1.
View Article and Find Full Text PDFPsychiatr Clin North Am
March 2025
Department of Neurology, Johns Hopkins University School of Medicine, Kennedy Krieger Institute, Baltimore, MD, USA.
The pathophysiology of tic disorders involves an alteration in the transmission of messages through the cortico-basal ganglia-thalamo-cortical circuit. A major requirement for the passage of a message through this circuit is an intact chemically mediated synaptic neurotransmitter system (ie, neurotransmitters and second messengers). This article reviews the scientific evidence supporting the involvement of a variety of neurotransmitters (ie, dopamine, glutamate, gamma-aminobutyric acid, serotonin, acetylcholine, and the opioid system).
View Article and Find Full Text PDFThe effect of Constraint-induced movement therapy (CIMT) or Intermittent theta-burst stimulation (iTBS) alone is limited in improving motor function after a stroke. In this study, we explored the efficacy and possible mechanisms in combination of CIMT and iTBS through behavioral evaluation, RNA sequencing, Golgi staining, transmission electronic microscope (TEM), high-performance liquid chromatography (HPLC), western blotting (WB) and immunofluorescence. Firstly, we observed that combination therapy is safe and effective, and it can significantly reduce the number of immature dendritic spines and increase the number of functional dendritic spines, the amount of glutamate (Glu) and the expression of Glu1 receptor (Glu1R).
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