An important function of all nervous systems is to control muscle contraction so that movements of the body are appropriate to promote survival. In most species specialized motor neurons convey the signals that represent the neural commands for contraction from the central nervous system to the muscle fibers. These signals are transmitted to the individual muscle fibers at highly differentiated...

Results from in vitro experiments, using the hypogastric nerve--vas deferens preparation, and the phrenic nerve--hemidiaphragm preparation of the guineapig, have been used to determine the separation between the neuromuscular and ganglionic blocking effects of atracurium and tubocurarine. Regression lines were used to calculate the concentrations of each drug (99% confidence limits) which would...

Experiments were performed to determine the role of acetylcholine (ACh) in neuromuscular transmission in the heart of the leech Hirudo medicinalis. Superfused or iontophoretically applied ACh rapidly depolarized both isolated heart muscle cells and muscle cells in isolated hearts in a dose-dependent manner. the depolarization was associated with a conductance increase of the muscle membrane tha...

Study of the literature on the physiology of neuromuscular transmission suggested two new methods of assessing the degree of neuromuscular block in the human subject. These were, first, a comparison of the height of the recorded twitch tensions developed in response to repeated single stimuli applied at differing frequencies and, second, examination of the extent of reduction in amplitude of tw...

Myasthenia gravis (MG) is an autoimmune disease characterized by fluctuating muscle weakness, caused by impaired neuromuscular transmission. Patients with MG can present other autoimmune diseases in association, commonly hypo or hyperthyroidism. The association of MG to demyelinating disease is rare and has been described before. We report on three Brazilian patients with MG that presented dist...

Antibodies directed against the post-synaptic neuromuscular junction protein, muscle specific kinase (MuSK) are found in a small proportion of generalized myasthenia gravis (MuSK-MG) patients. MuSK is a receptor tyrosine kinase which is essential for clustering of the acetylcholine receptors (AChRs) at the neuromuscular junction, but the mechanisms by which MuSK antibodies (MuSK-Abs) affect neu...

Activation of the tropomyosin-related kinase receptor B (TrkB) by brain-derived neurotrophic factor acutely regulates synaptic transmission at adult neuromuscular junctions (NMJs). The role of TrkB kinase activity in the maintenance of NMJ function and structure at diaphragm muscle NMJs was explored using a chemical-genetic approach that permits reversible inactivation of TrkB kinase activity i...

Study of the literature on the physiology of neuromuscular transmission suggested two new methods of assessing the degree of neuromuscular block in the human subject. These were, first, a comparison of the height of the recorded twitch tensions developed in response to repeated single stimuli applied at differing frequencies and, second, examination of the extent of reduction in amplitude of tw...

A robust infrastructure for solving time-dependent diffusion using the finite element package FEtk has been developed to simulate synaptic transmission in a neuromuscular junction with realistic postsynaptic folds. Simplified rectilinear synapse models serve as benchmarks in initial numerical studies of how variations in geometry and kinetics relate to endplate currents associated with fast-twi...

Emerging data implicate microRNAs (miRNAs) in the regulation of synaptic structure and function, but we know little about their role in the regulation of neurotransmission in presynaptic neurons. Here, we demonstrate that the miR-310-313 cluster is required for normal synaptic transmission at the Drosophila larval neuromuscular junction. Loss of miR-310-313 cluster leads to a significant enhanc...