Development of mammalian nerve-muscle synapses in culture: lack of interference by antibodies to the neural cell adhesion molecule N-CAM and its L2/HNK-1 carbohydrate epitope.
Rat myotubes were cultured with embryonic mouse spinal cord explants. After 4 days of co-culture, (miniature) endplate potentials, (M)EPPs, could be detected in 20-40% of the nerve-contacted myotubes. Polyclonal antibodies against the neural cell adhesion molecule N-CAM and monoclonal antibodies to its L2/HNK-1 carbohydrate epitope were tested for possible effects on synapse formation in this system. Co-cultures that were started and maintained in the presence of Fab fragments of these antibodies developed functional synapses to the same extent as did control cultures. Staining with an anti-IgG antibody demonstrated that added Fab fragments had bound to neurites and that an excess was present in the medium. These findings suggest that even if N-CAM and the L2/HNK-1 epitope were involved in early stages of muscle-nerve contact, they are not essential for the formation of electrophysiologically active synapses.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology / Q000502:physiology*; D002241:Carbohydrates / Q000276:immunology; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002478:Cells, Cultured; D000939:Epitopes / Q000276:immunology* / Q000502:physiology; D008564:Membrane Potentials; D051379:Mice; D009132:Muscles / Q000166:cytology / Q000502:physiology; D009469:Neuromuscular Junction / Q000276:immunology / Q000502:physiology*; D051381:Rats; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000502:physiology
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D002241:Carbohydrates; D015815:Cell Adhesion Molecules; D000939:Epitopes