title: Switching ability of over trained movements in a Parkinson's disease rat model.
abstract: Patients with Parkinson's disease show unbalanced capability to manage self-paced vs externally driven movements, or automatic-associated movements with respect to the intended voluntary movements. We studied the effect of a selective loss of dopaminergic terminals within the striatum and the execution of a well-learned set-shifting task as revealed using tyrosine hydroxylase immunoreactivity and magnetic resonance imaging in the rat. We found that, both in the externally cued condition, and in the externally-internally driven switching task, the cue-dependent constraints interfered with motor readiness in over training condition. The unilateral dopaminergic striatal depletion enhanced the switch-induced performance differences in favour of the internally-externally cued transition. Dopamine depleted rats, in fact, were impaired to produce an alternative motion when task switching required to change from an over trained behaviour, towards an alternative self-paced response. The comparative analysis of behavioural, tyrosine hydroxylase immunoreactivity and magnetic resonance imaging data, revealed a shrinkage of the lesioned striatum, and an enlargement of the ipsilateral ventricle that could provide useful markers for monitoring pathological changes occurring during early stages of Parkinson's disease in vivo.
authors.affiliation: Department of Life, Health and Environmental Sciences, University of L'Aquila, Via Vetoio, 67100 L'Aquila, Italy. tizianamarilena.florio@univaq.it
authors.forename: Tiziana M
authors.initials: TM
authors.lastname: Florio
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Confalone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sciarra
authors.forename: Antonello
authors.initials: A
authors.lastname: Sotgiu
authors.forename: Marcello
authors.initials: M
authors.lastname: Alecci
mesh_terms: D000161:Acoustic Stimulation / Q000009:adverse effects; D000818:Animals; D001288:Attention / Q000502:physiology*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D003463:Cues; D004195:Disease Models, Animal; D007839:Functional Laterality; D008279:Magnetic Resonance Imaging; D008297:Male; D009068:Movement / Q000502:physiology*; D016627:Oxidopamine / Q000633:toxicity; D010300:Parkinson Disease / Q000209:etiology / Q000534:rehabilitation*; D010805:Physical Conditioning, Animal / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D013565:Sympatholytics / Q000633:toxicity; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D013565:Sympatholytics; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase