Long-term administration of excess zinc impairs learning and memory in aged mice.

Long-term administration of excess zinc impairs learning and memory in aged mice. J Toxicol Sci. 2019;44(10):681-691 Authors: Yoshida K, Gi M, Fujioka M, Teramoto I, Wanibuchi H Abstract Zinc (Zn) is an essential element, but excess amounts are known to cause neurotoxic effects. The risk of excessive Zn intake is increased by supplementing food intake with dietary supplements. Ageing affects many cellular processes that predispose individuals to neurodegeneration. Indeed, the prevalence of senile dementia such as Alzheimer's disease, Parkinson's disease, and vascular-type dementia increases with age. As such, we investigated the effects of long-term exposure to excess Zn on learning and memory in aged mice. ICR-JCL female mice (aged 26 weeks) were administered 0, 200, or 500 ppm Zn as zinc chloride in drinking water for 30 weeks. After 30-week administration, aged female animals were subjected to Y-maze, novel object recognition, and step-through passive avoidance tests. Chronic exposure to Zn did not inhibit learning and memory in the Y-maze test, but dose-dependently inhibited learning and memory in novel object recognition and step-through passive avoidance tests. These results indicate the potential for chronic Zn exposure to dose-dependently inhibit both long-term and novel object recognition memory. Results of microarray analysis revealed significant changes in gene expression of transthyretin and many olfactory receptors in the hippocampus of Zn-tr...
Source: Journal of Toxicological Sciences - Category: Toxicology Tags: J Toxicol Sci Source Type: research

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Fight Aging! publishes news and commentary relevant to the goal of ending all age-related disease, to be achieved by bringing the mechanisms of aging under the control of modern medicine. This weekly newsletter is sent to thousands of interested subscribers. To subscribe or unsubscribe from the newsletter, please visit: https://www.fightaging.org/newsletter/ Longevity Industry Consulting Services Reason, the founder of Fight Aging! and Repair Biotechnologies, offers strategic consulting services to investors, entrepreneurs, and others interested in the longevity industry and its complexities. To find out m...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
AbstractPurpose of ReviewWe summarize structural (s)MRI findings of gray matter (GM) atrophy related to cognitive impairment in Alzheimer ’s disease (AD) and Parkinson’s disease (PD) in light of new analytical approaches and recent longitudinal studies results.Recent FindingsThe hippocampus-to-cortex ratio seems to be the best sMRI biomarker to discriminate between various AD subtypes, following the spatial distribution of tau pathology, and predict rate of cognitive decline. PD is clinically far more variable than AD, with heterogeneous underlying brain pathology. Novel multivariate approaches have been used t...
Source: Current Neurology and Neuroscience Reports - Category: Neuroscience Source Type: research
Abstract Chronic neuroinflammation is a common feature of the pathogenic mechanisms involved in various neurodegenerative age-associated disorders, such as Alzheimer's disease, multiple sclerosis, Parkinson's disease, and dementia. In particular, persistent low-grade inflammation may disrupt the brain endothelial barrier and cause a significant increase of pro-inflammatory cytokines and immune cells into the cerebral tissue that, in turn, leads to microglia dysfunction and lose of neuroprotective properties. Nowadays, growing evidence highlights a strong association between persistent peripheral inflammation, as w...
Source: Current Pharmaceutical Design - Category: Drugs & Pharmacology Authors: Tags: Curr Pharm Des Source Type: research
Abstract BACKGROUND: We investigated the structural changes associated with Alzheimer's disease, dementia with Lewy bodies and Parkinson disease dementia by means of cortical thickness analysis. METHODS: Two hundred and forty-five participants: 76 Alzheimer's disease, 65 dementia with Lewy bodies, 29 Parkinson disease dementia and 76 cognitively normal controls underwent 3-T T1-weighted magnetic resonance imaging and clinical and cognitive assessments. We implemented FreeSurfer to obtain cortical thickness estimates to contrast patterns of cortical thinning across groups and their clinical correlates. RE...
Source: The Australian and New Zealand Journal of Psychiatry - Category: Psychiatry Authors: Tags: Aust N Z J Psychiatry Source Type: research
Abstract Neurodegenerative diseases (NDs) are age-dependent; among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most frequent. Similarly, cerebrovascular damage can induce the development of vascular-related disorders that share common features with AD and PD, respectively, named vascular dementia (VD) and vascular parkinsonism (VP). To date, ND diagnosis is mainly clinical; therefore, since these disorders show similar symptoms, their correct discrimination may be difficult. We detected 23 ND-associated microRNAs (miRNAs) by literature mining and investigated their serum expression in a coh...
Source: Cellular and Molecular Neurobiology - Category: Cytology Authors: Tags: Cell Mol Neurobiol Source Type: research
AbstractOver the last two decades, a number of studies have underlined the importance of lysosomal ‐based degradative pathways in maintaining the homeostasis of post‐mitotic cells, and revealed the remarkable contribution of a functional autophagic machinery in the promotion of longevity. In contrast, defects in the clearance of organelles and aberrant protein aggregates have been linked to a ccelerated neuronal loss and neurological dysfunction. Several neurodegenerative disorders, among which Alzheimer disease (AD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) to name a few, are associated wi...
Source: Journal of Neurochemistry - Category: Neuroscience Authors: Tags: Review Source Type: research
This study investigated the possibility of significant interactions between these molecules that are involved in the late‐stage of Alzheimer's disease (AD), Parkinson disease (PD), Parkinson disease dementia, dementia with Lewy bodies, and controls using ELISA assays, autoradiography , and mRNA in situ hybridization assay. Interestingly, lower DNA/RNA oxidative adducts levels in the caudate and putamen of diseased brains were observed with the exception of an increased DNA oxidative product in the caudate of AD brains. Similar changes were found for dopamine concentration and ve sicular monoamine transporter 2 densities....
Source: Journal of Neurochemistry - Category: Neuroscience Authors: Tags: Original Article Source Type: research
In this study, we hypothesized that moderately and chronically reducing ACh could attenuate the deleterious effects of aging on NMJs and skeletal muscles. To test this hypothesis, we analyzed NMJs and muscle fibers from heterozygous transgenic mice with reduced expression of the vesicular ACh transporter (VAChT), VKDHet mice, which present with approximately 30% less synaptic ACh compared to control mice. Because ACh is constitutively decreased in VKDHet, we first analyzed developing NMJs and muscle fibers. We found no obvious morphological or molecular differences between NMJs and muscle fibers of VKDHet and contro...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
In this study, the enhanced mice live somewhat longer than their unmodified peers, though not as much longer as is the case for the application of telomerase gene therapy. The mice do also exhibit reduced cancer risk, however. The scientists here class telomere shortening as a cause of aging, which is not a point universally agreed upon. Reductions in average telomere length in tissues looks much more like a downstream consequence of reduced stem cell activity than an independent mechanism. Researchers obtain the first mice born with hyper-long telomeres and show that it is possible to extend life without any geneti...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
MONDAY, Oct. 21, 2019 -- Former professional soccer players have a significantly increased risk of death from brain diseases such as Alzheimer's and Parkinson's, a new study finds. Former soccer players were about 3.5 times more likely to die of...
Source: Drugs.com - Daily MedNews - Category: General Medicine Source Type: news
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