Hyperproliferation of synapses on spinal motor neurons of Duchenne muscular dystrophy and myotonic dystrophy patients.

Synapses on the motor neurons of patients with Duchenne muscular dystrophy (DMD) and myotonic dystrophy (MD) were studied immunohistochemically using antibodies against synaptobrevin and synaptophysin. Some motor neurons showed hyperproliferation of synapses on the soma and the proximal dendrites. Hyperproliferated synapses were non-cholinergic, because they were not identified with antibodies against vesicular acetylcholine transporter. Regeneration of motor nerve terminals in patients with muscular diseases may affect reorganization of the subsets of central synapses.