Ultrastructural reactions of spinal ganglia to tri-ortho-cresyl-phosphate: effects of neurotoxicity.

The ultrastructure of neurons in spinal ganglia of the domestic fowl poisoned with tri-ortho-cresyl-phosphate (TOCP) shows characteristic changes. The light neurons react to TOCP by a marked increase in the number of neurofilaments. These neurons also contain mitochondria in various degenerative stages. Several of the altered mitochondria show an increasing osmiophilia. Some of the darker neurons display a hypertrophy of the endoplasmic reticulum or a relative increase of neurofilaments. The mitochondria in some of these cells show early stages of degeneration. These changes appear 13 days after TOCP ingestion.