title: Differential blocking effects of the monoclonal anti-GQ1b IgM antibody and alpha-latrotoxin in the absence of complement at the mouse neuromuscular junction.
abstract: Numerous in vitro electrophysiological studies found different effects of anti-ganglioside antibodies on neuromuscular transmission. Since a complement-dependent, latrotoxin-like effect has been described for the mouse monoclonal anti-GQ1b IgM antibody (termed CGM3), we here investigated the effect of CGM3 and alpha-latrotoxin by means of the perfused macro-patch clamp electrode in mice hemidiaphragms in the absence of complement. The CGM3 mab depressed evoked quantal release dose-dependently, whereas the rate of spontaneous releases and the amplitude of postsynaptic currents was not significantly affected. Alpha-latrotoxin induced an increase in spontaneous releases followed by a blockade of evoked quantal release, this was not altered by CGM3. The complement-independent presynaptic block by CGM3 was different from the action of alpha-latrotoxin.
authors.affiliation: Neurologische Klinik der Universität Würzburg, Josef Schneider Strasse 11, 97080 Würzburg, Germany. brigitte.buchwald@mail.uni-wuerzburg.de
authors.forename: Brigitte
authors.initials: B
authors.lastname: Buchwald
authors.forename: Raheleh
authors.initials: R
authors.lastname: Ahangari
authors.forename: Klaus V
authors.initials: KV
authors.lastname: Toyka
mesh_terms: D000109:Acetylcholine / Q000032:analysis; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D003165:Complement System Proteins; D003964:Diaphragm / Q000187:drug effects / Q000502:physiology; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005732:Gangliosides / Q000037:antagonists & inhibitors / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009469:Neuromuscular Junction / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D013111:Spider Venoms / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D005732:Gangliosides; D007075:Immunoglobulin M; D013111:Spider Venoms; C020763:alpha-latrotoxin; C039129:GQ1b ganglioside; D003165:Complement System Proteins; D000109:Acetylcholine