Healthy aging is accompanied by increased false remembering in addition to reduced successful remembering in older adults. Neuroimaging studies implicate age-related differences in the involvement of ...medial temporal lobe and fronto-parietal regions in mediating highly confident false recollection. However, no studies have directly examined the relationship between white matter microstructure and false recollection in younger and older adults. Using diffusion-weighted imaging and probabilistic tractography, we examined how white matter microstructure within tracts connecting the hippocampus and the fronto-parietal retrieval network contribute to false recollection rates in healthy younger and older adults. We found only white matter microstructure within the fornix contributed to false recollection rates, and this relationship was specific to older adults. Fornix white matter microstructure did not contribute to true recollection rate, nor did common white matter contribute to false recollection, suggesting fornix microstructure is explicitly associated with highly confident false memories in our sample of older adults. These findings underlie the importance of examining microstructural correlates associated with false recollection in younger and older adults.
•Fornix white matter microstructure is negatively associated with false recollection in older, but not younger, adults.•Fornix microstructure does not underlie an ‘old’ responding bias.•Common white matter microstructure also does not contribute to false recollection.
Past research suggests that working memory (WM) and motor control may engage similar cognitive and neural mechanisms in older adults, particularly when task difficulty increases. However, much of ...this evidence arises from comparisons across behavioral and imaging studies that test only one of the foregoing functional domains. The current study used fMRI within the same group of older adults to investigate whether WM and motor control recruit common mechanisms, and whether recruitment increased with task demand and age. A conjunction analysis across WM and motor tasks revealed engagement of several frontoparietal regions as a function of increasing task demand. A separate conjunction analysis which included age as a predictor showed comparable regions exhibit increased recruitment with both increasing task demand and age. Results suggest that the recruitment of common frontoparietal regions across WM and motor tasks in response to task difficulty is maintained across the older adult lifespan.
Background
Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a rare leukodystrophy with motor impairment due to biallelic mutations in DARS2, which ...encodes mitochondrial aspartyl tRNA synthetase. Progressive ataxia is the primary feature.
Objective
The study objective is to determine the feasibility of remotely collecting quantitative gait and balance measures in LBSL.
Methods
The study design uses wearable accelerometers and the scale for the assessment and rating of ataxia (SARA) scale to assess gait and postural sway in LBSL and control participants' homes through video conferencing.
Results
Lateral step variability (LSV), which indicates stride variability, and elevation of the step at mid‐swing are increased for LBSL patients during brief walking tests. During stance with the eyes closed, LBSL participants show rapid accelerations and decelerations of body movement covering a large sway area and path. Both the LSV and sway area during stance with the feet together and eyes closed correlate strongly with the SARA.
Conclusions
Wearable accelerometers are valid and sensitive for detecting ataxia in LBSL patients during remote assessments. The finding of large increases in the sway area during stance with the eyes closed is intriguing since dorsal column dysfunction is universally seen in LBSL. This approach can be applied to related rare diseases that feature ataxia.
Adrenomyeloneuropathy (AMN), the slow progressive phenotype of adrenoleukodystrophy (ALD), has no clinical plasma biomarker for disease progression. This feasibility study aimed to determine whether ...metabolomics and micro‐RNA in blood plasma provide a potential source of biomarkers for AMN disease severity. Metabolomics and RNA‐seq were performed on AMN and healthy human blood plasma. Biomarker discovery and pathway analyses were performed using clustering, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and regression against patient's clinical Expanded Disability Status Score (EDSS). Fourteen AMN and six healthy control samples were analyzed. AMN showed strong disease‐severity‐specific metabolic and miRNA clustering signatures. Strong, significant clinical correlations were shown for 7‐alpha‐hydroxy‐3‐oxo‐4‐cholestenoate (7‐HOCA) (r2 = 0.83, p < 0.00001), dehydroepiandrosterone sulfate (DHEA‐S; r2 = 0.82, p < 0.00001), hypoxanthine (r2 = 0.82, p < 0.00001), as well as miRNA‐432‐5p (r2 = 0.68, p < 0.00001). KEGG pathway comparison of mild versus severe disease identified affected downstream systems: GAREM, IGF‐1, CALCRL, SMAD2&3, glutathione peroxidase, LDH, and NOS. This feasibility study demonstrates that miRNA and metabolomics are a source of potential plasma biomarkers for disease severity in AMN, providing both a disease signature and individual markers with strong clinical correlations. Network analyses of affected systems implicate differentially altered vascular, inflammatory, and oxidative stress pathways, suggesting disease‐severity‐specific mechanisms as a function of disease severity.
For more than 175 years, the remarkable botanical drawings made in Canton by a Chinese artist working with the British East India Company supercargo John Bradby Blake, were handed down from ...generation to generation within the same family. They first appeared publicly in 1959 when the estate of Sir Frederick Cripps of Ampney Park, Gloucestershire, came up for auction. A Bristol art dealer bought the drawings, but on the other side of the Atlantic, Paul Mellon had other ideas for them. This article follows the trail from London, via Ampney Park and Bristol, to Oak Spring, Virginia.
The drug taxol has been hailed by many in the cancer community as a major breakthrough in the treatment of cancer. It has already been approved in use against ovarian and advanced breast cancer in ...many countries world-wide. Taxol has also promoted profound debates in the policy arena not, as one might expect, because of the characteristics or purposes of the drug itself, but because of other far-reaching effects. Taxol is a complex compound found in the bark of the Pacific yew tree, primarily in Oregon and Washington in the USA. The bark was first collected in 1962 and cytotoxicity demonstrated in 1964. Yet it was not until 1989 that the first results of clinical trials were reported. In the US taxol was then rushed through the Food and Drug Administration’s regulatory procedures, approval being granted for use in refractory ovarian cancer in 1992. The controversies surrounding taxol surfaced in 1989 and grew substantially over the next few years. In this paper we examine two principal controversies concerning taxol, the first of which focused on apparent conflicts between the needs of environmental protection and those of cancer chemotherapy. Although the media portrayed this as a clash of interests between the environment and people with cancer, we argue that it was an attempt to increase lay participation in biomedical decision making and policy formulation. The second controversy was between health policy and the transfer of public scientific property to the corporate sector. The pharmaceutical company Bristol–Myers Squibb was given exclusive rights to provide taxol from Pacific yew trees under a Co-operative Research and Development Agreement signed in 1991. While this was seen to be in the US Government’s (as well as the company’s) interest, it provoked a public reaction questioning the terms and consequences of the transfer of publicly generated scientific knowledge to the private sector.
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