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Gait disturbances are common in the rat model of Parkinson's disease (PD) by administrating 6-hydroxydopamine. However, few studies have simultaneously assessed spatiotemporal gait indices and the kinematic information of PD rats during overground locomotion. This study utilized a simple, accurate, and reproducible method for quantifying the spatiotemporal and kinematic changes of gait patterns in hemiparkinsonian rats. A transparent walkway with a tilted mirror was set to capture underview footprints and lateral joint ankle images using a high-speed and high-resolution digital camera. The footprint images were semi-automatically processed with a threshold setting to identify the boundaries of soles and the critical points of each hindlimb for deriving the spatiotemporal and kinematic indices of gait. Following PD lesion, asymmetrical gait patterns including a significant decrease in the step/stride length and increases in the base of support and ankle joint angle were found. The increased footprint length, toe spread, and intermediary toe spread were found, indicating a compensatory gait pattern for impaired locomotor function. The temporal indices showed a significant decrease in the walking speed with increased durations of the stance/swing phase and double support time, which was more evident in the affected hindlimb. Furthermore, the ankle kinematic data showed that the joint angle decreased at the toe contact stage. We conclude that the proposed gait analysis method can be used to precisely detect locomotor function changes in PD rats, which is useful for objective assessments of investigating novel treatments for PD animal model. [ABSTRACT FROM AUTHOR]

Abstract: Gait disturbances similar to those of human Parkinson''s disease (PD) can be observed in animals after administration of neurotoxin 6-hydroxydopamine (6-OHDA) to induce unilateral nigrostriatal dopamine depletion. However, the relationship between gait disturbances and dopamine depletion following 6-OHDA infusion has not been determined. The present study investigated the longitudinal changes of spatiotemporal gait patterns using a walkway system to acquire footprints and lateral limb images over a 6-week period following unilateral 6-OHDA injection into the medial forebrain bundle of rats. Our results indicated that hemiparkinsonian rats exhibited changes in gait patterns, as compared to normal controls, and pre-lesion levels, including a significantly decreased walking speed and step/stride length as well as an increased base of support and foot angle. The relative percentage of the gait cycle was also altered, showing an increase in the stance to swing ratio, which was more evident in the affected hindlimb. Time-course observations showed that these gait disturbances occurred as early as 4 days post-lesion and gradually increased up to 42 days post-injury. The extents of gait disturbances were compared with conventional apomorphine-induced turning behavior and akinesia bar tests, which were also apparent at 4 days post-lesion but remained relatively unchanged after 28 days. Our time-course gait analysis of a unilateral 6-OHDA rodent model provides insight into the compensatory changes of motor functions during the 6-week development of a nigrostriatal lesion, which might be useful for future objective assessment of novel treatments for human PD subjects. [Copyright &y& Elsevier]