Comparison of 6-hydroxydopamine-induced medial forebrain bundle and nigrostriatal terminal lesions in a lateralised nose-poking task in rats.
The nigrostriatal degeneration underlying Parkinson's disease (PD) is commonly modeled in experimental animals by injection of the neurotoxin 6-hydroxydopamine (6-OHDA). Although a wide variety of simple behavioural screens exist to assess the impact of such dopamine lesions, more complex tasks that assess multiple parameters of an animal's performance may provide a more sensitive measure of the resulting functional impairment. This study assessed the performance of two unilateral lesion models of PD in a lateralised nose-poking task in the nine-hole box test apparatus. This task assesses the accuracy and speed of movements to either side of a rats' head, as well as a number of errors of performance. Rats with complete unilateral dopamine depletion (induced by injection of 6-OHDA into the medial forebrain bundle (MFB)) attempted fewer trials and committed more procedural errors than controls. They developed a marked ipsilateral responding bias, with a reduced accuracy for contralateral stimuli. They were also slower to react to contralateral stimuli and to complete movements bilaterally. Rats with unilateral nigrostriatal terminal lesions (induced by multiple injections of 6-OHDA in the striatum) developed a similar pattern of deficits, but they were significantly less impaired and spontaneously recovered to pre-operative levels by 4 months post-lesion. This experiment confirms that the lateralised nose-poking task may be a powerful tool for assessment of the nature of deficit and recovery in rats with complete but not partial unilateral dopamine lesions.
Dowd
Eilís
E
Brain Repair Group, School of Biosciences, Cardiff University, Wales, Cardiff CF10 3US, UK. dowde@cf.ac.uk
Dunnett
Stephen B
SB
D018663:Adrenergic Agents; D000818:Animals; D035841:Behavioral Research / Q000379:methods; D004298:Dopamine / Q000378:metabolism; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology*; D007839:Functional Laterality / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008474:Medial Forebrain Bundle / Q000187:drug effects / Q000502:physiology*; D023421:Models, Animal; D017072:Neostriatum / Q000187:drug effects / Q000502:physiology*; D009410:Nerve Degeneration / Q000139:chemically induced; D016627:Oxidopamine; D010300:Parkinson Disease / Q000503:physiopathology*; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology*
D018663:Adrenergic Agents; D016627:Oxidopamine; D004298:Dopamine