Abstract: Objective To explore the feasibility of a modified micro-cannula for intra-cerebral administration of 6-hydroxydopamine(6-OHDA) in order to establish a Parkinsonian mouse model. Methods Twenty female mice(C57BL/6J) were randomly divided into 2 groups with 10 in each: experimental group (new micro-cannula) and control group (regular Hamilton syringe). Following unilateral injection of 6-OHDA, the behavioral test and histological microscopy were performed. Results All mice in experimental group showed the morphology of apomorphine-induced rotational asymmetry, but the same results were found in only 5 mice from control group. Total number of rotations away from the lesion side in 30 minutes showed 6-OHDA-induced motor deficits at day 7 in both groups, which was significantly attenuated at day 28 in control group (P＜0.05). After 28 days of 6-OHDA injection, significant reduction in the number of rotations was observed in control mice as compared with that of experimental group (P＜0.05). As immunohistochemistry showed that the total number of remaining dopaminergic neurons significantly decreased in the substantial nigra of the experimental mice as compared with the control mice(P＜0.05). Moreover, more local astrocytes underwent activation, part of which acquired the properties of neural precursor cells in control mice. Conclusions Intrastriatal injection of 6-OHDA using the new micro-cannula is a feasible technology in the development of a more reliable Parkinsonian model of mice.

Key words: Parkinson's disease, 6-hydroxydopamine(6-OHDA), stereotactic frame, new micro-cannula, dopaminergic neurons