Increased c-Jun expression in neurons affected by lysolecithin-induced demyelination in rats

The objective of this study was to investigate whether the expression of c-Jun is involved in the neuronal response to experimental demyelination. Lysolecithin-induced demyelination was generated in two distinct neural systems in rats: in the pontocerebellar and the septohippocampal pathways. Six days after the stereotaxic injections of lysolecithin, expression of the immediate early gene c-Jun was visualized by immunohistochemistry. Lesion-specific expression of the Jun protein was observed in neurons whose axons transverse the demyelinated area. Unlike the neural response to axotomy, lysolecithin treatment did not alter the expression of the neuropeptide galanin in the septohippocampal pathway. These results suggest that c-Jun protein expression might represent one step in the neuronal response to demyelination and that this response might be distinct in its downstream events from axotomy.