Neurotoxicity and Behavioral Effects of Thiram in Rats

Cheng-Chun Lee, Paul J. Peters
1976 Environmental Health Perspectives  
Eight of 24 female rats fed 66.9 mg/kg-day of thiram developed neurotoxicity. The neurotoxic effects were characterized by ataxia and paralysis of the hind legs. There were demyelination, degeneration of the axis cylinders, and presence of macrophages in the nerve bundle of the sciatic nerve. Degeneration in the ventral horn of the lower lumbar region of the spinal cord was evidenced by chromatolysis of motorneurons, pyknosis, and satellitosis. During a second experiment, 4 of 24 females fed
more » ... f 24 females fed 65.8 mg/kgday also developed ataxia and paralysis. An additional 9 females showed clasping of the hind feet when picked up by the tail. Nerve conduction could not be measured for one severely ataxic rat and the electromyogram indicated a loss of motor unit function. Histopathology of this rat, along with the others, suggests the peripheral nerve as the primary site of the lesion. Thiram also caused behavioral changes in apparently normal rats. The walking pattern of the hind legs was altered with decreases in stride width and the angle between contralateral steps. These rats required significantly more shockmotivations and cleared a lower height in a jump/climb ability test. An open-field study indicated that thiram caused hyperactivity in the nonataxic rats of both sexes. Three of 24 rats fed 95.8 mg/kg-day of ferbam also developed ataxia or paralysis. 42 Environmental Health Perspectives
doi:10.2307/3428607 fatcat:lc5frcnqufcgvgopl3ek27n44e