M(1)-muscarinic acetylcholine (ACh) receptors (M(1)R) were directly demonstrated immunocytochemically in electronmicroscopic images of rat diaphragm neuromuscular junctions (NMJ). Specific electron-dense granules were located at presynaptic nerve ending membranes and in the sarcolemma in the depths of postsynaptic folds. This first visualization of M(1)R on both sides of the NMJ is in agreement with previous pharmacological data on the regulatory role of M(1)R in quantal and non-quantal ACh release.

• MeSH
• Diaphragm immunology   MeSH
• Financing, Organized MeSH
• Immunohistochemistry MeSH
• Rats MeSH
• Motor Endplate metabolism   ultrastructure   MeSH
• Neuromuscular Junction metabolism   ultrastructure   MeSH
• Synaptic Transmission physiology   MeSH
• Receptors, Muscarinic metabolism   MeSH
• Synaptic Membranes metabolism   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH