Ultrastructure of neurofibrillary tangles in progressive supranuclear palsy.

Ultrastructure of neurofibrillary tangles was investigated on the subcortical neurons of an autopsy case of progressive supranuclear palsy. The patient was a 64-year-old female and suffered from her illness for 9 years. Two kinds of ultrastructure were observed in the subcortical neurofibrillary tangles, i.e. that 150 A straight tubules and the 220 A twisted tubules. They appeared separately in each neuron and a transition between these two structures could not be remarked. Besides, a few particles with a paracrystalline hexagonal structure were observed in some subcortical neurons.