The dopaminergic basis of cognitive and motor performance in Alzheimer's disease.
A crucial role of corticostriatal dopaminergic networks in cognitive and motor processes has been well established but largely unexplored in Alzheimer's disease (AD). The study investigated the relationship between striatal DA (D(2)) receptor availability and specific aspects of cognitive (sustained visual attention, spatial planning, word recognition) and motor (speed and dexterity) function in 24 people with mild to moderate AD. In vivo dopamine DA (D(2)) receptor availability was determined with [(11)C] raclopride (RAC) positron emission tomography (PET). Imaging data were analysed using both region of interest (ROI) and voxel-based approaches. Higher [(11)C] RAC binding was associated with increased motor speed and, paradoxically, poorer attentional performance. These findings are broadly consistent with previously conducted studies in healthy older adults and would suggest that the use of DA (D(2)) receptor agonists as an adjunctive treatment strategy in AD may have dissociable effects upon cognitive function.
Reeves
Suzanne
S
Section of Old Age Psychiatry, MRC Centre for Neurodegeneration Research, Institute of Psychiatry at King's College London, De Crespigny Park, Camberwell, UK. suzanne.j.reeves@kcl.ac.uk
Mehta
Mitul
M
Howard
Robert
R
Grasby
Paul
P
Brown
Richard
R
D000544:Alzheimer Disease / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001667:Binding, Competitive / Q000502:physiology; D001923:Brain Chemistry / Q000502:physiology; D001931:Brain Mapping; D003071:Cognition / Q000187:drug effects / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D004185:Disability Evaluation; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000009:adverse effects; D018492:Dopamine Antagonists; D009068:Movement / Q000187:drug effects / Q000502:physiology; D009069:Movement Disorders / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000378:metabolism*
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D020891:Raclopride; D004298:Dopamine