Changes of dopaminergic neuron morphology and expression of c-fos in corpusstriatum after rat substantia nigra lesion

Objective:To observe the morphology of dopaminergic neurons in the substantia nigra pars compacta (SNc) and c-fos expression in the caudate-putamen of 6-hydroxydopamine (6-OHDA) lesioned rats, and to explore the correlation between c-fos expression and lesion size.Methods: Rats received a unilateral injection of 6-OHDA into SNc. The abnormal rotations induced by apomorphine (APO) were investigated at 1 d,7 d, 14 d and 21 d after lesion. Meanwhile, changes of the morphology of dopaminergic neurons and c-fos expression were observed with HE and Nissl body staining, electron microscopic and immunocytochemistry methods. Results: The number of dopaminergic neurons decreased gradually in the lesioned site and its ultrastructure damage was more severe. Eighty percent of dopaminergic neurons were lost. c-fos was up-regulated in the ipsilateral striatum and contralateral rotations surpassed 7 r/min. Conclusion:Dopaminergic neurons loss is the foundation of behavioral changes and up-regulation of c-fos in the ipsilateral caudate-putamen.Intrinsic relations may exist between them.