Neuromuscular Junction Physiology and Pathophysiology

  • Jaap J. Plomp
Part of the Current Clinical Neurology book series (CCNEU)


The neuromuscular junction (NMJ) is a cholinergic synapse that connects a motor neuron to a skeletal muscle fiber. To enable sustained tetanic contraction of skeletal muscle, the NMJ must reliably transmit the impulses from the presynaptic motor neuron to the postsynaptic muscle fiber. This seemingly simple task is enabled by the existence of a complex system of pre- and postsynaptic structural subcellular specializations and functional molecular machineries. These are responsible for (1) the development and maintenance of the synaptic structure, (2) the controlled presynaptic release of the neurotransmitter acetylcholine, and (3) the postsynaptic translation of this chemical message into an excitatory electrical response. The many factors in this synaptic system all have their inherent risks and vulnerabilities, e.g., in autoimmunity or upon intoxication. The resulting malfunctions compromise successful neuromuscular transmission and may lead to disturbances of muscle contraction. This chapter describes the normal NMJ structure and electrophysiological function and briefly discusses the pathophysiology occurring in myasthenia gravis (with autoantibodies against postsynaptic acetylcholine receptors) and some of the related NMJ synaptopathies.


Acetylcholine receptor Autoimmunity Electrophysiology Endplate Endplate potential Fatigue Muscle-specific kinase Myasthenia gravis Neuromuscular junction Neurotransmitter Safety factor Skeletal muscle Synapse 



The author gratefully acknowledges support by the Prinses Beatrix Spierfonds, Stichting Spieren voor Spieren, and L’Association Française contre les myopathies.


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© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of NeurologyLeiden University Medical CentreLeidenThe Netherlands

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