Role And Expression Of Fosb/△fosb In The Development Of Levodopa-induced Dyskinesias In Parkinsonian Rat Model

Objective To investigate the role of FosB/△FosB in the striatum of hemiparkinsonian rats in developing levodopa-induced dyskinesias.Methods Hemiparkinsonian rats models were established by stereotaxical injection of 6-hydroxydopamine (6-OHDA) in the left medial forebrain bundle (MFB). Then completely lesioned and partially lesioned Parkinson's disease (PD) rat models were selected strictly. The levodopa treated group received the levodopa for 3, 9 or 29 days respectively. The partially lesioned group was given the same dose of levodopa for 29 days. The control group received normal saline for 29 days. The completely lesioned PD rat models which were not graven the treatment of levodopa survived for 9, 54 or 167 days respectively. The sham-operation group which was injected with normal saline in the left MFB survived for 167 days as the control group. The curative effect of the levodopa was assessed by the rotation behavior. The both sides of striatums of all rats in those groups were taken out and then the quantitive expression of FosB/△FosB in the striatum was detected through immunohistochemistry staining and western blotting.Results The frequency of the rotation was decreased progressively (P<0.01), but the AIM scores were increased gradually (P<0.01) as the levodopa treatment continued. Compared with the completely lesioned group, the scores of AIM of rats in partially lesioned group were significantly lower (P<0.01). The positive cell number of the FosB/△FosB, optical density of the FosB/△FosB and the gray value of the△FosB in the lesioned striatum were increased gradually in the course of levodopa treatment (P<0.01). The positive cell number of the FosB/△FosB, optical density of the FosB/△F osB and the gray value of the△FosB in the lesioned striatum were higher than that in the partially lesioned group after the treatment of levodopa(P<0.01). There was no significant change in the positive cell number of the FosB/△FosB, optical density of the FosB/△FosB or the gray value of the△FosB in the lesioned striatum of completely lesioned group which were not graven the treatment of levodopa (P<0.01).Conclusions The change of the expression of△FosB in the striatum may be attributed to the development of levodopa-induced motor complications.