Inclusions similar to Hirano bodies in urinary bladder neurons of dogs

Unusual intracytoplasmatic inclusions were found in urinary bladder neurons in dogs. The plate-like inclusions were composed of thin filaments, and when viewed en face, appeared as oval or angular bodies with regular lattice work array. When viewed in a transverse section, they were of rod-like shape and were composed of longitudinal filaments and transverse bars. The inclusions were observed in all ganglia of the urinary bladders studied. Three-dimensional reconstruction of the inclusions was made, using a tilting device. By means of this reconstruction, it could be demonstrated that their ultrastructure is similar to that of Hirano bodies which occur in human neurons of the central nervous system in cases of neurodegenerative diseases. The authors suggest that unusual intraneuronal inclusions represent a peculiarity in cytoskeletal protein assembly typical of canine urinary bladder neurons.