The role of reference frames in memory recollection

2019 ◽  
Vol 42 ◽  
Author(s):  
Giuseppe Riva ◽  
Daniele Di Lernia ◽  
Andrea Serino ◽  
Silvia Serino
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Spatial Memory ◽  
Reference Frames ◽  
Critical Role ◽  
Explanatory Model ◽  
Spatial Context ◽  
Translation Process ◽  
Encoding And Retrieval

Abstract In this commentary on Bastin et al., we suggest that spatial context plays a critical role in the encoding and retrieval of events. Specifically, the translation process between the viewpoint-independent content of a memory and the viewpoint-dependent stimuli activating the retrieval (mental frame syncing) plays a critical role in spatial memory recollection. This perspective also provides an explanatory model for pathological disturbances such as Alzheimer's disease.

scholarly journals Alzheimer's disease and periodontitis - an elusive link

2014 ◽  
Vol 60 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Abhijit N. Gurav
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Inflammatory Cytokines ◽  
Critical Role ◽  
Anaerobic Bacteria ◽  
Systemic Infection ◽  
Low Grade ◽  
Inflammatory Status ◽  
Pro Inflammatory Cytokines

Alzheimer's disease is the preeminent cause and commonest form of dementia. It is clinically characterized by a progressive descent in the cognitive function, which commences with deterioration in memory. The exact etiology and pathophysiologic mechanism of Alzheimer's disease is still not fully understood. However it is hypothesized that, neuroinflammation plays a critical role in the pathogenesis of Alzheimer's disease. Alzheimer's disease is marked by salient inflammatory features, characterized by microglial activation and escalation in the levels of pro-inflammatory cytokines in the affected regions. Studies have suggested a probable role of systemic infection conducing to inflammatory status of the central nervous system. Periodontitis is common oral infection affiliated with gram negative, anaerobic bacteria, capable of orchestrating localized and systemic infections in the subject. Periodontitis is known to elicit a "low grade systemic inflammation" by release of pro-inflammatory cytokines into systemic circulation. This review elucidates the possible role of periodontitis in exacerbating Alzheimer's disease. Periodontitis may bear the potential to affect the onset and progression of Alzheimer's disease. Periodontitis shares the two important features of Alzheimer's disease namely oxidative damage and inflammation, which are exhibited in the brain pathology of Alzheimer's disease. Periodontitis can be treated and hence it is a modifiable risk factor for Alzheimer's disease.

scholarly journals Microglial ApoD Induced NLRC4 Inflammasome Activation Promotes Alzheimer’s Disease Progression

2021 ◽  
Author(s):  
Yaliang Yu ◽  
Jianzhou Lv ◽  
Dan Ma ◽  
Ya Han ◽  
Yaheng Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Critical Role ◽  
Microglia Activation ◽  
Inflammatory Factors ◽  
Inflammasome Activation ◽  
Cellular Interactions ◽  
Brain Functions ◽  
Chronic Neuroinflammation

Abstract Alzheimer’s disease (AD) is a progressive neurodegenerative disease with no effective therapies. It’s well-known that chronic neuroinflammation plays a critical role in the onset and progression of AD. Proper neuronal-microglial interactions are essential for brain functions. However, as the main existence of immune cells, determining the role of microglia in Alzheimer’s neuroinflammation and the associated molecular basis has been challenging. Herein, the inflammatory factors in the sera of AD patients were detected and the association with microglia activation was analyzed. The mechanism regarding the microglial inflammation was investigated. The IL6 and TNF-α were found to be significantly increased in the AD stage. Further analysis revealed microglia were extensively activated in AD cerebra releasing mounts of cytokines to impair the neural stem cells (NSCs) function. Moreover, ApoD induced NLRC4 inflammasome was activated in microglia, which gave rise to the proinflammatory phenotype. Targeting the microglial ApoD promoted NSCs self-renewal and inhibited neuron apoptosis. These findings demonstrate the critical role of ApoD in microglial inflammasome activation, and for the first time reveal that microglia-induced inflammation suppresses neuronal proliferation. Our studies establish the cellular basis for microglia activation in AD progression, and shed lights on cellular interactions important for AD treatment.

scholarly journals New Insights on the Role of Manganese in Alzheimer’s Disease and Parkinson’s Disease

2019 ◽  
Vol 16 (19) ◽  
pp. 3546 ◽  
Author(s):  
Airton Cunha Martins ◽  
Patricia Morcillo ◽  
Omamuyovwi Meashack Ijomone ◽  
Vivek Venkataramani ◽  
Fiona Edith Harrison ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Parkinson’S Disease ◽  
Alzheimer's Disease ◽  
Parkinson's Disease ◽  
Critical Role ◽  
Essential Trace Element ◽  
Neuronal Function ◽  
Therapy Options ◽  
Physiological Processes

Manganese (Mn) is an essential trace element that is naturally found in the environment and is necessary as a cofactor for many enzymes and is important in several physiological processes that support development, growth, and neuronal function. However, overexposure to Mn may induce neurotoxicity and may contribute to the development of Alzheimer’s disease (AD) and Parkinson’s disease (PD). The present review aims to provide new insights into the involvement of Mn in the etiology of AD and PD. Here, we discuss the critical role of Mn in the etiology of these disorders and provide a summary of the proposed mechanisms underlying Mn-induced neurodegeneration. In addition, we review some new therapy options for AD and PD related to Mn overload.

scholarly journals May “Mitochondrial Eve” and Mitochondrial Haplogroups Play a Role in Neurodegeneration and Alzheimer's Disease?

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Elena Caldarazzo Ienco ◽  
Costanza Simoncini ◽  
Daniele Orsucci ◽  
Loredana Petrucci ◽  
Massimiliano Filosto ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Critical Role ◽  
Protective Role ◽  
Oxygen Species ◽  
Mitochondrial Haplogroups ◽  
Normal Ageing ◽  
Apoptotic Pathways ◽  
Mitochondrial Eve

Mitochondria, the powerhouse of the cell, play a critical role in several metabolic processes and apoptotic pathways. Multiple evidences suggest that mitochondria may be crucial in ageing-related neurodegenerative diseases. Moreover, mitochondrial haplogroups have been linked to multiple area of medicine, from normal ageing to diseases, including neurodegeneration. Polymorphisms within the mitochondrial genome might lead to impaired energy generation and to increased amount of reactive oxygen species, having either susceptibility or protective role in several diseases. Here, we highlight the role of the mitochondrial haplogroups in the pathogenetic cascade leading to diseases, with special attention to Alzheimer's disease.

scholarly journals Anti-Inflammatory Gene Therapy Improves Spatial Memory Performance in a Mouse Model of Alzheimer’s Disease

2021 ◽  
pp. 1-8
Author(s):  
Tai June Yoo
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gene Therapy ◽  
Mouse Model ◽  
Spatial Memory ◽  
Memory Performance ◽  
Critical Role ◽  
Amyloid Β ◽  
Amyloid Β Protein ◽  
Anti Inflammatory

The immune system plays a critical role in neurodegenerative processes involved in Alzheimer’s disease (AD). In this study, a gene-based immunotherapeutic method examined the effects of anti-inflammatory cellular immune response elements (CIREs) in the amyloid-β protein precursor (AβPP) mouse model. Bi-monthly intramuscular administration, beginning at either 4 or 6 months, and examined at 7.5 through 16 months, with plasmids encoding Interleukin (IL)-10, IL-4, TGF-β polynucleotides, or a combination thereof, into AβPP mice improved spatial memory performance. This work demonstrates an efficient gene therapy strategy to downregulate neuroinflammation, and possibly prevent or delay cognitive decline in AD.

Inhibition of microRNA-155 Alleviates Cognitive Impairment in Alzheimer’s Disease and Involvement of Neuroinflammation

2019 ◽  
Vol 16 (6) ◽  
pp. 473-482 ◽  
Author(s):  
Dandan Liu ◽  
Dandan Zhao ◽  
Yingkai Zhao ◽  
Yan Wang ◽  
Yong Zhao ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Functions ◽  
Spatial Working Memory ◽  
Critical Role ◽  
Learning Performance ◽  
Intracerebroventricular Infusion ◽  
Tnf Α ◽  
Current Report

Background: Neuroinflammation has important effects on cognitive functions in the pathophysiological process of Alzheimer’s Disease (AD). In the current report, we determined the effects of microRNA-155 (miR-155) on the levels of IL-1β, IL-6 and TNF-α, and their respective receptors in the hippocampus using a rat model of AD. Methods: Real-time RT-PCR, ELISA and western blot analysis were used to examine the miR-155, PICs and PIC receptors. The Morris water maze and spatial working memory tests were used to assess cognitive functions. Results: miR-155 was increased in the hippocampus of AD rats, accompanied by amplification of IL-1β, IL-6 and TNF-α. Intracerebroventricular infusion of miR-155 inhibitor, but not its scramble attenuated the increases of IL-1β, IL-6 and TNF-α and upregulation of their receptors. MiR-155 inhibitor also attenuated upregulation of apoptotic Caspase-3 in the hippocampus of AD rats. Notably, inhibition of miR- 155 or PIC receptors largely recovered the impaired learning performance in AD rat. Conclusion: We showed the critical role of miR-155 in regulating the memory impairment in AD rats likely via engagement of neuroinflammatory mechanisms, suggesting that miR-155 and its signaling molecules may present prospects in preventing and/or improving the development of the impaired cognitive functions in AD.

scholarly journals The MS4A gene cluster is a key modulator of soluble TREM2 and Alzheimer’s disease risk

2019 ◽  
Vol 11 (505) ◽  
pp. eaau2291 ◽  
Author(s):  
Yuetiva Deming ◽  
Fabia Filipello ◽  
Francesca Cignarella ◽  
Claudia Cantoni ◽  
Simon Hsu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Genome Wide Association Study ◽  
Disease Risk ◽  
Critical Role ◽  
Age At Onset ◽  
Mechanistic Explanation ◽  
Genetic Modifiers ◽  
A Genome

Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in cerebrospinal fluid (CSF) has been associated with Alzheimer’s disease (AD). TREM2 plays a critical role in microglial activation, survival, and phagocytosis; however, the pathophysiological role of sTREM2 in AD is not well understood. Understanding the role of sTREM2 in AD may reveal new pathological mechanisms and lead to the identification of therapeutic targets. We performed a genome-wide association study (GWAS) to identify genetic modifiers of CSF sTREM2 obtained from the Alzheimer’s Disease Neuroimaging Initiative. Common variants in the membrane-spanning 4-domains subfamily A (MS4A) gene region were associated with CSF sTREM2 concentrations (rs1582763; P = 1.15 × 10−15); this was replicated in independent datasets. The variants associated with increased CSF sTREM2 concentrations were associated with reduced AD risk and delayed age at onset of disease. The single-nucleotide polymorphism rs1582763 modified expression of the MS4A4A and MS4A6A genes in multiple tissues, suggesting that one or both of these genes are important for modulating sTREM2 production. Using human macrophages as a proxy for microglia, we found that MS4A4A and TREM2 colocalized on lipid rafts at the plasma membrane, that sTREM2 increased with MS4A4A overexpression, and that silencing of MS4A4A reduced sTREM2 production. These genetic, molecular, and cellular findings suggest that MS4A4A modulates sTREM2. These findings also provide a mechanistic explanation for the original GWAS signal in the MS4A locus for AD risk and indicate that TREM2 may be involved in AD pathogenesis not only in TREM2 risk-variant carriers but also in those with sporadic disease.

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