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- Granholm, Ann-Charlotte E, et al.
(författare)
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Neuropathological findings in Down syndrome, Alzheimer's disease and control patients with and without SARS-COV-2 : preliminary findings
- 2024
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 147, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- The SARS-CoV-2 virus that led to COVID-19 is associated with significant and long-lasting neurologic symptoms in many patients, with an increased mortality risk for people with Alzheimer's disease (AD) and/or Down syndrome (DS). However, few studies have evaluated the neuropathological and inflammatory sequelae in postmortem brain tissue obtained from AD and people with DS with severe SARS-CoV-2 infections. We examined tau, beta-amyloid (Aβ), inflammatory markers and SARS-CoV-2 nucleoprotein in DS, AD, and healthy non-demented controls with COVID-19 and compared with non-infected brain tissue from each disease group (total n = 24). A nested ANOVA was used to determine regional effects of the COVID-19 infection on arborization of astrocytes (Sholl analysis) and percent-stained area of Iba-1 and TMEM 119. SARS-CoV-2 antibodies labeled neurons and glial cells in the frontal cortex of all subjects with COVID-19, and in the hippocampus of two of the three DS COVID-19 cases. SARS-CoV-2-related alterations were observed in peri-vascular astrocytes and microglial cells in the gray matter of the frontal cortex, hippocampus, and para-hippocampal gyrus. Bright field microscopy revealed scattered intracellular and diffuse extracellular Aβ deposits in the hippocampus of controls with confirmed SARS-CoV-2 infections. Overall, the present preliminary findings suggest that SARS-CoV-2 infections induce abnormal inflammatory responses in Down syndrome.
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| 2. |
- Nicastri, Casey M., et al.
(författare)
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BDNF mediates improvement in cognitive performance after computerized cognitive training in healthy older adults
- 2022
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Ingår i: Alzheimer’s & Dementia. - : John Wiley & Sons. - 2352-8737. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The often-cited mechanism linking brain-derived neurotrophic factor (BDNF) to cognitive health has received limited experimental study. There is evidence that cognitive training, physical exercise, and mindfulness meditation may improve cognition. Here, we investigated whether improvements in cognition after these three types of structured interventions are facilitated by increases in BDNF. Methods A total of 144 heathy older adults completed a 5-week intervention involving working memory/cognitive training, physical exercise, mindfulness meditation, or an active control condition. Serum BDNF levels and Digit Symbol Test (DST) performance were measured pre- and post-intervention. Results Linear mixed models suggested that only the cognitive training group demonstrated augmentation of BDNF and DST performance relative to the control condition. Path analysis revealed that changes in BDNF mediate intervention-related improvement in task performance. Regression analyses showed that, across all intervention conditions, increased BDNF levels were associated with increased DST scores. Discussion This study appears to be the first to suggest that BDNF helps mediate improvements in cognition after working memory training in healthy older adults. Highlights Older adults were randomized to physical activity, mindfulness, cognitive training (computerized cognitive training (CCT), or control. CCT, but no other condition, led to increased serum brain-derived neurotrophic factor (BDNF) levels. CCT led to improvement on the untrained Digit Symbol Test (DST) of speed/working memory. Path analysis: increases in BDNF mediate intervention-related improvement on DST. Increases in BDNF associated with improved DST across all experimental groups.
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