Dopaminergic Modulation of Visual-Spatial Working Memory in Parkinson’s DiseaseCosta A. · Peppe A. · Dell’Agnello G. · Carlesimo G.A. · Murri L. · Bonuccelli U. · Caltagirone C.
aIRCCS, Fondazione Santa Lucia, e bClinica Neurologica, Università di Roma ‘Tor Vergata’, Roma, e cDipartimento di Neuroscience, Clinica Neurologica, Università di Pisa, Italia
Visual-spatial working memory (WM) impairment is frequently associated with the early stage of Parkinson’s disease (PD). The aim of this study was to evaluate the performance of a group of PD patients in visual-spatial and visual-object WM tasks and to investigate the effect of administering the dopaminergic agonist apomorphine (experiment 1) or the dopamine precursor L-dopa (experiment 2) on the performance of tests assessing these functions. To study WM processes, the PD patients and age-matched normal controls were given an n-back task paradigm. In both experiments, the PD patients were submitted to two evaluations: one after a 12-hour therapy washout and the other 15 min after a subcutaneous infusion of apomorphine (average 0.04 mg/kg) or 20/30 min after L-dopa intake (200 mg p.o.). The apomorphine infusion had a worsening effect on reaction times in both visual-spatial and visual-object WM tasks, but it did not influence performance accuracy. Instead, L-dopa administration had a ameliorative effect on accuracy and reaction times in both visual-spatial and visual-object tasks. These results highlight the role of dopamine in the modulation of the WM function in PD patients.
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Accepted: August 19, 2002
Number of Figures : 5, Number of Tables : 2, Number of References : 60
Dementia and Geriatric Cognitive Disorders
Vol. 15, No. 2, Year 2003 (Cover Date: Released January 2003)
Journal Editor: V. Chan-Palay, New York, N.Y.
ISSN: 1420–8008 (print), 1421–9824 (Online)
For additional information: http://www.karger.com/journals/dem