Parkinson's disease is the motor disorder which results from the selective degeneration of the dopaminergic neurons in the substantia nigra (SN) and the deficiency of dopamine in the corpus striatum (CS). But etiological factors are still unknown. In this study, we made parkinsonian rat models which were under oxidative stress injecting 6-OHDA in SN. According to the time transition after neurotoxin injection we made the coronal sections of SN immunohistochemical staining by anti-Tyrosine hydroxylase (TH) and calbindin-D_28K antibody. We compared the survival rate (%) of calbindin-D_28K- immunoreactive cells with that of TH-immunoreactive cells to confirm the suggested role of calbindin-D_28K which may protect dopaminrgic neurons against the cytotoxicity according to the time transition after 6-OHDA injection. In parkinsonian rat models which were sacrificed 7 d, 10 d, 14 d, 17 d after the injection of 6-OHDA, the survival rates of calbindin-D_28K-immunoreactive neurons is significantly higher than that of TH- immunoreactive neurons (p＞0.05). We suggest that calbindin-D_28K containing neurons tend to be spared during the acute period of parkinsonian rat models, calbindin-D_28K helps to protect neurons against excitotoxicity. This is consistent with the proposed calbindin-D_28K function as an intraneuronal calcium buffer.

Keywords: Calbindin-D_28K, TH, Parkinson's disease, substantia nigra, rat