Establishment and MRI analysis of rat modei of Parkinson's disease

Objective: To evaluate rat modei of Parkinson's disease (PD) induced by unilateral nigral lesion or striatum lesion with 6-hydroxydopamine (6-OHDA) using behavior and MRI manifestation. Methods: 40 male Wistar rats were allotted into 3 groups randomly. The substantia nigra-lesioned group had 20 rats, with 18 in the striatum-lesioned group and 2 in pseudosurgery group. We stereotaxically impaired the substantia nigra in l point and striatum in 2 points and observed the rolling of rat induced by apomorphine in different stage, further examined the lesions of substantia nigra and striatum of PD rats in vivo under MRI. Results: 7 rats were induced to show obviously rolling behavior at the 2nd week after lesion of substantia nigra (7 rolls/min). The success ratio of PD modei was 35%. While in striatum-lesioned group, 11 rats rolled at the 2nd week with rolling rate less than 4 rolls/min. The rolling rate was less than 5 rolls/min at the 3rd week, and more than 7 rolls/min after the 5th week and remaining stable. The success ratio of PD modei was 61.1%. The lesioned substantia nigra and striatum of PD rats showed obviously low MRI signal. The low signal regions shrank in correspondence with the time extended, and disappeared at the end of the 5th week. Conclusions: The PD rat modei gotten from bi-point lesions of striatum by small dose of 6-OHDA is more effective according to the clinical progress of PD patients with a higher success rate. It's a perfect modei to study PD. MRI scanning can be used to observe the lesions of PD rat modei in vivo continually, which is an available means to evaluate and examine the PD rat modei objectively.