The ultrastructure of tricresylphosphate poisoning in primates. 3. Studies on alterations in neuronal soma.

This report deals with the ultrastructural changes observed in neurons of the posterior root ganglion of slow loris (Nycticebus coucang) following administration of tricresylphosphate (TCP) 0.2 ml/kg body weight for 10 days. The observed changes involved the rough and smooth endoplasmic reticulum profiles, neurofilaments, Golgi complex as well as lipofuscin pigment. Nissl substance was markedly dispersed to the periphery of the neuron. Membranous profiles of the smooth endoplasmic reticulum were lost. Neurofilaments were markedly increased and manifested neurofibrillary tangles or else were scattered over the cytoplasm. Golgi complexes were dilated and there was a marked increase in lipofuscin. These observations suggest that TCP produces degenerative changes in the organelles of sensory neurons similar to those seen at the height of chromatolysis produced by mechanical interference in the dorsal root ganglia and other neurons.