Cuprizone-induced demyelination in Wistar rats; electrophysiological and histological assessment.

OBJECTIVES Multiple Sclerosis (MS) is a disease that affects the Central Nervous System by destructing myelin shield and also can affects the peripheral nervous system. Demyelination is acquired characteristics disease and appears with the degeneration of myelin which protects the axons. Cuprizone (CPZ) model is a toxic demyelination model. The purpose of this study was to develop an MS model by cuprizone exposure to Wistar rats. MATERIALS AND METHODS Rats were separated into control and experimental groups and daily cuprizone was administered to experimental groups for 4, 5, 6 and 7 weeks. At the end of the experiments, spinal nerve conduction velocity was measured by EMG detected from the gastrocnemius muscle. After scarification, cerebrum and cerebellum of the animals were taken for histopathological investigation. RESULTS Spinal cord nerve conduction velocity (SNCV) of control animals was 76.54 m/s. Whereas SNCV of the rats that were feed with CPZ for 6 weeks was significantly reduced to 46.35 m/s in comparison with the control group. Demyelinated areas and vacuolization were seen on the brain sections of CPZ exposed rats. CONCLUSIONS SNCV of the rats were feed with cuprizone began tendency of decrease after 4th weeks. These reductions were observed as maximum at 6th weeks. At 7th week increments were observed at SNCV. These results indicated that 6 weeks of cuprizone feedings could be suitable to bring into existence of MS model in Wistar rats.