title: The grid-walking test: assessment of sensorimotor deficits after moderate or severe dopamine depletion by 6-hydroxydopamine lesions in the dorsal striatum and medial forebrain bundle.
abstract: 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.
authors.affiliation: Center for Behavioral Neuroscience, University of Duesseldorf, Universitaetstr. 1, 40225 Duesseldorf, Germany.
authors.forename: O Y
authors.initials: OY
authors.lastname: Chao
authors.forename: M E
authors.initials: ME
authors.lastname: Pum
authors.forename: J-S
authors.initials: JS
authors.lastname: Li
authors.forename: J P
authors.initials: JP
authors.lastname: Huston
mesh_terms: D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000502:physiology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D007839:Functional Laterality / Q000187:drug effects; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008474:Medial Forebrain Bundle / Q000187:drug effects / Q000378:metabolism*; D009422:Nervous System Diseases / Q000139:chemically induced* / Q000523:psychology*; D016627:Oxidopamine / Q000633:toxicity*; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000523:psychology; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013565:Sympatholytics / Q000633:toxicity*; D016138:Walking / Q000502:physiology
chemical_list: D000978:Antiparkinson Agents; D018765:Dopamine Uptake Inhibitors; D013565:Sympatholytics; D007980:Levodopa; D016627:Oxidopamine; D000661:Amphetamine; D004298:Dopamine