[Neurofilament hypertrophy induced in the rabbit spinal cord after intracisternal injection of aluminum chloride (author's transl)].

The cytological changes induced in the spinal cords of rabbits by intracisternal injections of aluminum chloride have been studied at the light- and electron-microscopic level for examining the progress of the 100 A filament hypertrophy. A moderate increase in the number of the 100 A filament was detected in perikarya of neurones in anterior, lateral, and dorsal horns 4--5 days after aluminum injection. Tangles of 100 A filament were seen in perikarya and proximal parts of dendrites in these neurones 1--2 weeks after the administration of aluminum. In this stage the tangles were detected as large clear spots at light-microscopic level. The 100 A filament bundles developed in between clumps of densely aggregated endoplasmic reticulum keeping close contact with this and squeezing other organella out. In high resolution studies the 100 A filament closely resembled the neurofilament in normal neurones in size and appearances and was seen to be connected with each other via side arms coming out from its wall. Relations between the endoplasmic reticulum and the 100 A filament hypertrophy was discussed referring to intoxicating effects of aluminum compounds on the nucleus of the neuron.