Journal of Alzheimer's disease : JAD
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Amyloid-β (Aβ) peptide-induced impairment of hippocampal synaptic plasticity is considered an underlying mechanism for memory loss in the early stages of Alzheimer's disease and its animal models. We previously reported inhibition of long-term potentiation (LTP) and miniature excitatory postsynaptic currents by oligomeric Aβ(1-42) at hippocampal synapses. While multiple cellular mechanisms could be involved in Aβ-induced synaptic dysfunction, blockade of activity-dependent autophosphorylation of Ca2+ and calmodulin-dependent protein kinase II (CaMKII) appeared to be a major component of Aβ action in our studies. ⋯ Aβ-induced LTP impairment, however, was prevented when slices were co-treated with neurotrophin 4 (NT4). Western blotting and immunohistochemical analyses confirmed that treatment with NT4 or brain-derived neurotrophic factor, another trkB-acting neurotrophin, could oppose Aβ action, enhancing autophosphorylation of CaMKII, and AMPA receptor phosphorylation at a CaMKII-dependent site. These findings support the view that CaMKII is a key synaptic target of Aβ toxicity as well as a potential therapeutic site of neurotrophins for Alzheimer's disease.
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For studying rare hereditary Alzheimer's disease (AD), transgenic (Tg) animal models overexpressing amyloid-beta protein precursor (AbetaPP) followed by increased amyloid-beta (Abeta) formation are used. In contrast, sporadic AD has been proposed to start with an insulin-resistant brain state (IRBS). We investigated the effect of IRBS induced by intracerebroventricularly (icv) administered streptozotocin (STZ) on behavior, glycogen synthase kinase-3 (GSK) alpha/beta content, and the formation of AD-like morphological hallmarks Abeta and tau protein in AbetaPP Tg2576 mice. ⋯ A linear negative correlation was detected between Abeta42 and cognition, and between GSK-3alpha/beta ratio and aggregated Abeta40+42. No marked necrotic and apoptotic changes were observed. In conclusion, IRBS may aggravate AD-like changes such as behavioral and increase the formation of pathomorphological AD hallmarks via GSK-3alpha/beta pathway in AbetaPP-overexpressing mice.
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Biography Historical Article
William R. Markesbery, M.D.: A legacy of excellence in Alzheimer's disease research and a life well-lived.
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Review Meta Analysis
Peri-operative risk management in patients with Alzheimer's disease.
The aim of this review is to identify an evidence-based perioperative management for patients affected by Alzheimer's disease (AD) that are scheduled to undergo surgery. This will minimize the negative effects of anesthesia and postoperative sedation and correct those perioperative variables possibly responsible for a decline in cognitive status and a worsening of AD. ⋯ The potential role of anesthesia, surgery, and postoperative analgosedation as risk factors for development of delirium are herein outlined. Finally, pain assessment instruments, as well as principles of management strategies for postoperative delirium in subjects with AD, are suggested.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Effects of rivastigmine in Alzheimer's disease patients with and without hallucinations.
Hallucinations in Alzheimer's disease (AD) may indicate greater cortical cholinergic deficits. Rivastigmine has shown larger treatment benefits versus placebo in dementia with Lewy bodies and Parkinson's disease dementia patients with hallucinations. In this retrospective, hypothesis-generating analysis, we investigated whether hallucinations in AD were associated with greater treatment benefits with rivastigmine. ⋯ Non-hallucinators showed a smaller significant treatment difference of -0.3 points (p< 0.05). Interaction testing suggested that differences in treatment effects were significant between hallucinators and non-hallucinators. Hallucinations predicted greater treatment responses to oral rivastigmine.