Behavioural assessment of dimethylsulfoxide neurotoxicity in rats

Dimethylsulfoxide (DMSO) is a solvent used to dissolve hydrophobic drugs. Recent studies have demonstrated that repeated administration of DMSO induces significant disorders of the peripheral nervous system. To address this issue, we have studied the behavioural effects of repeated intraperitoneal injections of various concentrations of DMSO (1.8-3.6-7.2%) in male Sprague-Dawley rats. Behavioural effects were assessed with a commonly used battery of sensory and motor tests. The motor tests used were actimeter and grip strength test. Sensory test used noxious and non-noxious mechanical (paw pressure test and von Frey hairs test) and thermal (plantar test and tail immersion test) stimuli. Clinical status of the animals was good throughout the experiment and no motor deficits were observed. Nevertheless, sensory assessment displayed a mechanical allodynia of short duration.