Changes in the ultrastructure of the neuromuscular synapse produced by tetanus toxin

Pozdnyakov, O. M.; Polgar, A. A.; Shirnova, V. S.; Крыжановский, Г. Н.

doi:10.1007/bf00796159

Cited by 3 publications

(2 citation statements)

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“…Synapses are not swollen; mitochondria, SSV, and large electron-dense vesicles are well preserved in terms of number, size, and intraterminal distribution. The only consistent change is an increase in the number of synaptic vesicles close to the cytosolic face of the presynaptic membrane (155,156,271,320,388,434,450,462,489). The BoNT/A poisoning of the frog NMJ causes the disappear-ance of the small membrane invagination normally detectable close to the active zones, which are believed to represent SSV fusion events (491).…”

Section: Structure and Electrophysiology Of Synapses Intoxicated Wmentioning

confidence: 99%

Neurotoxins Affecting Neuroexocytosis

Schiavo

Matteoli

Montecucco

2000

Physiological Reviews

1,155

1,126

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Nerve terminals are specific sites of action of a very large number of toxins produced by many different organisms. The mechanism of action of three groups of presynaptic neurotoxins that interfere directly with the process of neurotransmitter release is reviewed, whereas presynaptic neurotoxins acting on ion channels are not dealt with here. These neurotoxins can be grouped in three large families: 1) the clostridial neurotoxins that act inside nerves and block neurotransmitter release via their metalloproteolytic activity directed specifically on SNARE proteins; 2) the snake presynaptic neurotoxins with phospholipase A(2) activity, whose site of action is still undefined and which induce the release of acethylcholine followed by impairment of synaptic functions; and 3) the excitatory latrotoxin-like neurotoxins that induce a massive release of neurotransmitter at peripheral and central synapses. Their modes of binding, sites of action, and biochemical activities are discussed in relation to the symptoms of the diseases they cause. The use of these toxins in cell biology and neuroscience is considered as well as the therapeutic utilization of the botulinum neurotoxins in human diseases characterized by hyperfunction of cholinergic terminals.

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Section: Structure and Electrophysiology Of Synapses Intoxicated Wmentioning

confidence: 99%

Neurotoxins Affecting Neuroexocytosis

Schiavo

Matteoli

Montecucco

2000

Physiological Reviews

1,155

1,126

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“…In contrast to the effect of T e N T and BoNTs on EPPs and MEPPs, the frequency of giant MEPPs is not altered or even increases in the intoxicated NMJ (Sellin et al 1983;Kim et al 1984;Thesleff, 1986;Molgo et al 1990). Careful morphological examinations of poisoned NMJs have shown no evident structural changes, except for an increase in the number of SSVs present at the active zones of synaptic terminals (Kryzhanovsky et al 1971;Podzdnyakov et al 1972;Duchen, 1973 a, b;Mellanby et al 1988;Neale et al 1989;Pecot-Dechavassine et al 1991;Hunt et al 1994).…”

Section: Presynaptic Activitymentioning

confidence: 99%

Structure and function of tetanus and botulinum neurotoxins

Montecucco

Schiavo

1995

Quart. Rev. Biophys.

449

309

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Tetanus and botulinum neurotoxins are produced by Clostridia and cause the neuroparalytic syndromes of tetanus and botulism. Tetanus neurotoxin acts mainly at the CNS synapse, while the seven botulinum neurotoxins act peripherally. Clostridial neurotoxins share a similar mechanism of cell intoxication: they block the release of neurotransmitters. They are composed of two disulfide-linked polypeptide chains. The larger subunit is responsible for neurospecific binding and cell penetration. Reduction releases the smaller chain in the neuronal cytosol, where it displays its zinc-endopeptidase activity specific for protein components of the neuroexocytosis apparatus. Tetanus neurotoxin and botulinum neurotoxins B, D, F and G recognize specifically VAMP/ synaptobrevin. This integral protein of the synaptic vesicle membrane is cleaved at single peptide bonds, which differ for each neurotoxin. Botulinum A, and E neurotoxins recognize and cleave specifically SNAP-25, a protein of the presynaptic membrane, at two different sites within the carboxyl-terminus. Botulinum neurotoxin type C cleaves syntaxin, another protein of the nerve plasmalemma. These results indicate that VAMP, SNAP-25 and syntaxin play a central role in neuroexocytosis. These three proteins are conserved from yeast to humans and are essential in a variety of docking and fusion events in every cell. Tetanus and botulinum neurotoxins form a new group of zinc-endopeptidases with characteristic sequence, mode of zinc coordination, mechanism of activation and target recognition. They will be of great value in the unravelling of the mechanisms of exocytosis and endocytosis, as they are in the clinical treatment of dystonias.

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Tetanus neurotoxin

Wellhöner

1982

Reviews of Physiology, Biochemistry and Pharmacology

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Changes in the ultrastructure of the neuromuscular synapse produced by tetanus toxin

Cited by 3 publications

References 1 publication

Neurotoxins Affecting Neuroexocytosis

Neurotoxins Affecting Neuroexocytosis

Structure and function of tetanus and botulinum neurotoxins

Tetanus neurotoxin

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