Neuromuscular synapse

In vertebrates, the spectrum of w-conotoxin targets is dependent not only on the species of animal being studied, but on the w-conotoxin being used. In chicks and frogs all synapses tested are almost completely inhibited by w-conotoxin GVIA, while in rodents, w-conotoxin GVIA does not inhibit the neuromuscular synapse, and only a fraction of CNS synapses tested are blocked. In contrast, w-conotoxin MVIIA acts much more reversibly and with a much reduced affinity for many amphibian, and some mammalian, synapses. 

Tyrosine phosphorylation has a role in the formation of the neuromuscular synapse 428... 

Tyrosine phosphorylation has a role in the formation of the neuromuscular synapse. For instance, the acetylcholine receptor (AChR) is concentrated at the postsynaptic membrane of the neuromuscular junction at a density of 10,000 receptors/pm2, which is about three orders of magnitude higher than that of the extrasynaptic region... 

Fu WM, Huang FL (1994) Potentiation by endogenously released ATP of spontaneous transmitter secretion at developing neuromuscular synapses in Xenopus cell cultures. Br J Pharmacol... 

Experience-Dependent Potentiation of Larval Neuromuscular Synapses Christoph M. Schuster... 

Figure 7.2. Stractures of synapses, a Some anatomical variations. Left An intemeural synapse connects two nerve cells. Middle A neuromuscular synapse (also called motor endplate) connects the terminal button of a motoneuron to a skeletal muscle cell. Right An automic nerve cell may form several secretory varicosities that release the transmitter in the target tissue, without forming a circtrmscribed contact zone with an individtral target cell, b Electron microcoscopy of a nemomnsctrlar synapse. The synaptic cleft is very narrow, so that diffusion of secreted transmitter to the receptors on the postsynaptic membrane is fast. Ntrmerous vesicles line up close to the presynaptic membrane. Note the striated myofilament in the postsynaptic cell, c Light microscopy. A single nemon branches out and sends terminal buttorrs to multiple muscle fibers.

The nerve cells that sit in the spinal cord and relay the instructions for voluntary movements to the skeletal muscle. The axons of these cells reach go all the way to the muscle cells and form the neuromuscular synapses discussed above. 

Palade GE, Palay SL. Electron microscope observations of in- 27. terneuronal and neuromuscular synapses. Anat. Rec. 1954 18 335. 

Nerve impulses are transmitted through the synaptic gap via chemical signals in the form of a specialized group of chemicals termed neurotransmitters. Neurotransmitters can also pass the neural impulse on to glands and muscles. Except where the neural synapses terminates on a muscle (neuromuscular synapse) or a gland (neuroglandular synapse), the synaptic gap is bordered by a presynaptic terminal portion of one neurcn and the dendrite of the postsynaptic neurcn. 

Black widow spider venom contains several different protein fractions. However, the high-molecular-weight neurotoxin is the only fraction that is of clinical significance. This neurotoxin acts at the neuromuscular synapse damaging nerve terminals and causing the release and ultimately the depletion... 

Thomas S, Robitaille R. 2001. Differential Frequency-Dependent Regulation of Transmitter Release by Endogenous Nitric Oxide at the Amphibian Neuromuscular Synapse. J Neurosci 21 1087-1095. 

Chen Y-H, Wu M-L, Fu W-M (1998b) Regulation of presynaptic NMDA responses by external and intracellular pH changes at developing neuromuscular synapses. J Neurosci 78 2982-2990. 

Fu W-M, Liou J-C, Lee Y-H, Liou H-C (1995) Potentiation of neurotransmitter release by activation of presynaptic glutamate receptors at developing neuromuscular synapses of Xenopus. J Physiol 489 813-823. 

Our previous investigation showed that oxime reactivators of ChE have direct influence on presynaptic and postsynaptic membranes after intoxication with OPC [7, 11]. In the ultrastructural investigation ofthe neuromuscular synapses after acute DDVP and Vx intoxications, the changes observed were similar to those resulting from neurotomy, which is the reason why we called this effect of organophosphorous compounds chemiconeurothomy [9], After i.m. application of reactivator of ChE TMB-4, the neuromuscular synapses recover their normal ultrastructure up to 10 days after intoxication. Without treatment, full recovery of ultrastructure will be after 30 days [9],... 

Williams AH et al (2009) MicroRNA-206 delays ALS progression and promotes regeneration of neuromuscular synapses in mice. Science 326(5959) 1549-1554... 

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