Disease relevance of Motor Endplate

• In myasthenia gravis, loss of acetylcholine receptors at motor end-plates is induced by antireceptor autoantibodies [1].
• Ultrastructural localization of acetylcholine receptor at the motor endplate: myasthenia gravis and other neuromuscular diseases [2].
• The motor end-plate fine structure and ultrastructural localization of acetylcholine receptors in amyotrophic lateral sclerosis [3].
• Myasthenia gravis (MG) is an autoimmune disease characterized by production of antibodies to acetylcholine receptor at the motor end-plate responsible for impairment of neuromuscular transmission [4].
• Mutations in alpha subunit genes have been linked to paroxysmal disorders such as epilepsy, long QT syndrome, and hyperkalemic periodic paralysis in humans, and motor endplate disease and cerebellar ataxia in mice [5].

High impact information on Motor Endplate

• MuSK is a receptor tyrosine kinase localized to the motor endplate, seemingly well positioned to receive a key nerve-derived signal [6].
• Neuronal nitric oxide synthase (nNOS) is concentrated at synaptic junctions in brain and motor endplates in skeletal muscle [7].
• Agrin is a nerve-derived factor that can induced molecular reorganizations at the motor endplate, but the mechanism of action of agrin remains poorly understood [6].
• Mutation of a new sodium channel gene, Scn8a, in the mouse mutant 'motor endplate disease' [8].
• These results suggest that expression of IFN-gamma at motor end plates provokes an autoimmune humoral response, similar to human MG, thus linking the expression of this factor with development of this disease [9].

Chemical compound and disease context of Motor Endplate

• The adverse effect of neostigmine on motor end-plates may have clinical relevance in the management of myasthenia gravis and may be partly responsible for the end-plate abnormalities previously reported in this disease [10].
• Diagnostic significance of IgG, C3, and C9 at the limb muscle motor end-plate in minimal myasthenia gravis [11].
• Pyroantimonate deposition patterns observed in the motor endplate myopathy following esterase inactivation [12].

Biological context of Motor Endplate

• Regulation of acetylcholine receptor gene expression by neural factors and electrical activity during motor endplate formation [13].
• 4. Nerve stimulation of group II muscle fibres evoked action potentials with a delayed repolarization phase, suggesting that a prolonged acetylcholine-induced conductance change occurs at motor end-plates [14].
• The motor end-plate specific form of acetylcholinesterase: appearance during embryogenesis and re-innervation of rat muscle [15].
• Expression of Nav1.6 sodium channels by Schwann cells at neuromuscular junctions: role in the motor endplate disease phenotype [16].
• Insertional mutation of the motor endplate disease (med) locus on mouse chromosome 15 [17].

Anatomical context of Motor Endplate

• No changes in the CGRP-containing motor end plates were observed either after treatment of neonatal rats with capsaicin or ablation of cell bodies from the central portion of the nodose ganglion [18].
• 5. The role of muscle activity in the biochemical differentiation of the developing motor end-plate was investigated in chick embryos which had been paralysed by repeated injections into the yolk sac of a curare-like agent, Flaxedil (May & Baker) [19].
• Once neuromuscular junctions had formed, golli immunoreactivity appeared in motor endplates and persisted to the latest age examined, P60 [20].
• Counts of muscle fibers, motor endplates, and acetylcholine receptors and measurement of total muscle protein indicated that the size of the superior oblique muscle in the chimera embryos was similar to that of the normal duck but significantly larger than the muscle in quail embryos [21].
• Interaction of imipramine with the ionic channel of the acetylcholine receptor of motor endplate and electric organ [22].

Associations of Motor Endplate with chemical compounds

• Increased uptake of acetylcholine-receptor antibody at motor endplate in myasthenic exacerbation [23].
• Reaction product was also noted in the junctional folds of the motor end plate of a denervated muscle [24].
• Deposition of immune complexes (IgG, C3, and C9) was demonstrated at the motor endplates of limb muscle (biceps brachii); primary synaptic clefts were widened, and postsynaptic folds were simplified [25].
• The supra-vital methylene blue technique was used to study motor end-plate morphology in 21 BD-1X rats, treated for 7 to 16 weeks with oral neostigmine bromide, and in five control animals [10].
• The effects of chloramphenicol isomers on the motor end-plate nicotinic receptor-ion channel complex [26].

Gene context of Motor Endplate

• The generally high levels of BChE activity in tissues, including the motor endplate, and the observation that mice live without AChE, suggest that BChE has an essential function in nullizygous mice and probably in wild-type mice as well [27].
• As NO has been shown to induce collapse and growth arrest on neuronal growth cones, down-regulation of sarcolemmal neuronal NOS may contribute to axonal regeneration and attraction to muscle fibers aiming at the formation of new motor endplates providing reinnervation and reconstitution of NOS expression [28].
• When epopeptide AB or Epo was locally injected into mice, the frequency of motor end plate sprouting in adjacent muscles increased in a manner similar to that induced by CNTF [29].
• Previous studies have suggested that axotomy in juvenile (< 2 months) Wld mice induced a progressive nerve terminal withdrawal from motor endplates [30].
• LIF deficiency leads to pronounced loss of distal axons and motor endplate alterations, whereas CNTF-and/or CT-1-deficient mice do not show significant changes in morphology of these structures [31].

Analytical, diagnostic and therapeutic context of Motor Endplate

• In an ex vivo model, human and mouse anti-GQ1b antibodies have been shown previously to induce a complement-dependent alpha-latrotoxin-like effect on the murine motor endplate, i.e. they bring about massive quantal release of acetylcholine and eventually block neuromuscular transmission [32].
• The time course of establishment of motor endplates and the subsequent developmental changes in their enteric and vagal innervation were examined in esophageal striated muscle of perinatal and adult C57/Bl6 mice by using immunocytochemistry and confocal laser scanning microscopy [33].
• When applied to rats (intraperitoneally) immediately after subcutaneous injection of soman (120 micrograms/kg) HI-6 (100 mg/kg) protected about 40% of the activity of acetylcholinesterase (AChE) in the motor end plate region of the diaphragm but did not protect AChE in the brain [34].
• Newly formed motor endplates were characterized using acetylcholinesterase staining and electron microscopy [35].
• Intraperitoneal injection of the thiol group blocker N-ethylmaleimide also causes marked inhibition of staining of motor end-plates by this method [36].

References