The toxic action of nitrobenzene,with special reference to the cerebellum

Abstract

The toxic action of nitrobenzene has been comparatively little studied in an experimental way. The investigations here reported have been in progress about two years. Dogs, cats, rabbits, guinea pigs, white rats and mice, hens, pigeons, frogs, and certain insects and blood parasites have been used. The animals have in all cases been exposed to air saturated with the vapor of the nitrobenzene at various temperatures in a special metal box of forty cubic feet capacity, and so arranged that good ventilation was insured. The periods of exposure varied from one to twenty-four hours, or even longer, as in case of rabbits and guinea pigs; with other animals the exposure was usually much shorter. The effects obtained vary with the type of animal somewhat. In dogs and birds the nervous system disturbances predominate, with lighter dosage, while in the other mammals used blood changes are more prominent, especially in severe poisoning. The details of these variations will be published later. At this time we give only the central nervous system reactions. These are of a type that are associated with cerebellar disturbance especially. Thus, in dogs an early asthenic condition in the limb and neck muscles, staggering gait, typical cerebellar nystagmus, unequal pupils, “circus” movements may be seen. In birds a body attitude and rotating motion of the head are strikingly similar to those in birds with cerebellar lesions. The animals may recover, sustain permanent disturbance of muscular coördination, or die. Symptoms develop at any time up to three or four days after exposure to the vapor.

Histological study of various parts of the brain and cord revealed remarkable chromatolytic changes, apparently confined to the Purkinje cells of the cerebellum, in all animals showing disturbed coordination.