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Duff, K.

Publications and source records attributed to Duff, K..

2 recordsLinked to original sources

Evidence for associations between Rey-Osterrieth Complex Figure test and motor skill learning in older adults

Age-related declines in motor learning may be related to poor visuospatial function. Thus, visuospatial testing could evaluate older adults potential for motor learning, which has implications for geriatric motor rehabilitation. To this end, the purpose of this study was to identify which visuospatial test is most predictive of motor learning within older adults. Forty-five nondemented older adults completed six standardized visuospatial tests, followed by three weekly practice sessions on a functional upper-extremity motor task. Participants were re-tested one month later on the trained task and another untrained upper-extremity motor task to evaluate the durability and generalizability of motor learning, respectively. Principal component analysis first reduced the dimensions of the visuospatial battery to two principal components for inclusion in a mixed-effects model that assessed one-month follow-up performance as a function of baseline performance and the principal components. Of the two components, only one was related to one-month follow-up. Factor loadings and post hoc analyses suggested that of the six visuospatial tests, the Rey-Osterrieth test (visual construction and memory) was related to one-month follow-up of the trained and untrained tasks. Thus, it may be plausible that older adults long-term motor learning capacity could be evaluated using the Rey-Osterrieth test, which would be feasible to administer prior to motor rehabilitation to indicate risk of non-responsiveness to therapy.

neuroscience

Atrophy associated with tau pathology precedes overt cell death in a mouse model of progressive tauopathy

In the early stages of Alzheimers disease (AD), tau pathology first develops in the entorhinal cortex (EC), then spreads to the hippocampus and at later stages, to the neocortex. Pathology in the neocortex correlates with impaired cognitive performance. Overall, tau pathology correlates well with neurodegeneration but the spatial and temporal association between tau pathology and overt volume loss is unclear. Using in vivo magnetic resonance imaging (MRI) with tensor-based morphometry (TBM) we mapped the spatio-temporal pattern of structural changes in a mouse model of AD-like progressive tauopathy. A novel, co-registered in vivo MRI atlas identified particular regions in the medial temporal lobe (MTL) that had significant volume reduction. The medial entorhinal cortex (MEC) and pre-/para-subiculum (PPS) had the most significant atrophy at the early stage, but atrophy then spread into the hippocampus, most notably, the CA1, dentate gyrus (DG) and subiculum (Sub). TBM-related atrophy in the DG and Sub preceded overt cell loss that has been reported in ex vivo studies in the same mouse model. By unifying an ex vivo 3D reconstruction of tau pathology with the TBM-MRI results we mapped the progression of atrophy in the MTL with the corresponding spread of tau pathology. Our study shows that there is an association between the spread of tau pathology and TBM-related atrophy from the EC to the hippocampus, but atrophy in the DG and Sub preceded overt cell loss. One Sentence SummarySpread of tau pathology in a mouse model of Alzheimers disease assessed by MRI was associated with reduced brain tissue volume but not neuronal loss.

neuroscience