The present study aims to evaluate the applicability of the grid-walking test in rats with moderate or severe dopamine-depletion incurred by unilateral nigro-striatal 6-hydroxydopamine (6-OHDA) lesions. Striatum samples were analyzed by high pressure liquid chromatography coupled to electrochemical detection (HPLC-EC) after behavioral testing. In Experiment 1, 2 weeks after the injection of 6-OHDA into the medial forebrain bundle, adult Wistar rats were divided into an l-3,4-dihydroxyphenylalanine (l-dopa) and a vehicle treatment group and their behaviors on the grid were compared. The severely lesioned animals (mean dopamine depletion of 92%) did not exhibit behavioral asymmetry in the number of contralateral foot-slips. However, l-dopa administration selectively reduced the number of foot-slips of the contralateral forelimb when compared with the vehicle group. In Experiment 2, 6-OHDA was injected into the dorsal striatum and foot-slips on the grid were analyzed 4, 9 and 13 days following the lesion. The rats with moderate dopamine-depletion (mean depletion of 54%) exhibited more contralateral forelimb-slips on all testing days. Compared with naive rats, hemiparkinsonian rats also showed more forelimb-slips. These results suggest that the grid-walking test should be a powerful and sensitive behavioral assay for sensory-motor deficits in rat models of nigro-striatal dopamine lesions.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Jan 27 2012|
Bibliographical noteFunding Information:
—This research was supported by the Forschungskommission of the Medical Faculty of the University of Düsseldorf and a grant from ERA-Net NEURON “Development and advancement in methods and technologies towards the understanding of brain diseases.” Owen Y. Chao received a stipend from the German Academic Exchange Programme (DAAD). We thank Ipek Sanal and Anna von Bothmer for measuring the behaviors on the grid.
- Dorsal striatum
- Hemiparkinsonian rats
- Medial forebrain bundle