Differential expression of FosB, c-Fos, and Zif268 in forebrain regions after acute or chronic l-DOPA treatment in a rat model of Parkinson's disease

A study was carried out to examine the effects of acute and chronic l-DOPA treatment on the distribution of the immediate-early gene (IEG) proteins (FosB, c-Fos, and Zif268) in forebrain regions in a unilateral 6-hydroxydopamine (6-OHDA) rat model of Parkinson's disease. During a course of chronic l-DOPA treatment (15 mg/day, 15 days), rats with a 6-OHDA lesion developed abnormal involuntary movements. Compared with the rats in the acute l-DOPA treatment group, those in the chronic treatment group had significantly more FosB-immunopositive cells in the anterior cingulate (Cg) and the dorsolateral caudate-putamen ipsilateral to the lesion and significantly fewer c-Fos-immunopositive cells in the Cg, the nucleus accumbens shell, and the basolateral nucleus of amygdala ipsilateral to the lesion. No significant difference was observed in the number of Zif268-immunopositive cells between the acute and chronic l-DOPA groups. In summary, differential expression of three IEG proteins was observed in the forebrain regions during a course of chronic l-DOPA treatment of 6-OHDA-treated hemiparkinsonian rats.

► Rats with 6-OHDA lesion developed abnormal involuntary movements during chronic l-DOPA treatment.
► Chronic l-DOPA treatment elevated FosB expression levels in anterior cingulate and caudate-putamen ipsilateral to lesion.
► Differential expression of FosB, c-Fos, and Zif268 during l-DOPA treatment was observed in forebrain of 6-OHDA rats.