Axonal Conduction Velocity in CA1 Area of Hippocampus is Reduced in Mouse Models of Alzheimer’s Disease

2020 ◽  
Vol 77 (4) ◽  
pp. 1383-1388
Author(s):  
Simon Gelman ◽  
Jonathan Palma ◽  
Afshin Ghavami
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Conduction Velocity ◽  
Action Potentials ◽  
Hippocampal Slices ◽  
Amyloid Β ◽  
Synaptic Inputs ◽  
Axonal Conduction ◽  
Compound Action Potentials

The timing of action potentials arrival at synaptic terminals partially determines integration of synaptic inputs and is important for information processing in the CNS. Therefore, axonal conduction velocity (VC) is a salient parameter, influencing the timing of synaptic inputs. Even small changes in VC may disrupt information coding in networks requiring accurate timing. We recorded compound action potentials in hippocampal slices to measure VC in three mouse models of Alzheimer’s disease. We report an age-dependent reduction in VC in area CA1 in two amyloid-β precursor protein transgenic mouse models, line 41 and APP/PS1, and in a tauopathy model, rTg4510.

[P3-073]: AXONAL CONDUCTION VELOCITY IN CA1 AREA OF HIPPOCAMPUS IS REDUCED IN MOUSE MODELS OF ALZHEIMER's DISEASE

2017 ◽  
Vol 13 (7S_Part_20) ◽  
pp. P959-P960
Author(s):  
Simon Gelman ◽  
Jonathan D. Palma ◽  
Afshin Ghavami ◽  
Geoffrey Tombaugh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Conduction Velocity ◽  
Axonal Conduction ◽  
Ca1 Area

Astrocyte Reactivity in Alzheimer’s Disease: Therapeutic Opportunities to Promote Repair

2021 ◽  
Vol 18 ◽  
Author(s):  
Nazanin Mirzaei ◽  
Nicola Davis ◽  
Tsz Wing Chau ◽  
Magdalena Sastre
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Mouse Models ◽  
Neurodegenerative Disorders ◽  
Amyloid Β ◽  
Neuroprotective Effects ◽  
Synaptic Density ◽  
Inflammatory Profile

: Astrocytes are fast climbing the ladder of importance in neurodegenerative disorders, particularly in Alzheimer’s disease (AD), with the prominent presence of reactive astrocytes sur- rounding amyloid β- plaques, together with activated microglia. Reactive astrogliosis, implying morphological and molecular transformations in astrocytes, seems to precede neurodegeneration, suggesting a role in the development of the disease. Single-cell transcriptomics has recently demon- strated that astrocytes from AD brains are different from “normal” healthy astrocytes, showing dys- regulations in areas such as neurotransmitter recycling, including glutamate and GABA, and im- paired homeostatic functions. However, recent data suggest that the ablation of astrocytes in mouse models of amyloidosis results in an increase in amyloid pathology as well as in the inflammatory profile and reduced synaptic density, indicating that astrocytes mediate neuroprotective effects. The idea that interventions targeting astrocytes may have great potential for AD has therefore emerged, supported by a range of drugs and stem cell transplantation studies that have successfully shown a therapeutic effect in mouse models of AD. In this article, we review the latest reports on the role and profile of astrocytes in AD brains and how manipulation of astrocytes in animal mod- els has paved the way for the use of treatments enhancing astrocytic function as future therapeutic avenues for AD.

Neuroprotective properties of mitochondria-targeted antioxidants of the SkQ-type

2016 ◽  
Vol 27 (8) ◽  
pp. 849-855 ◽  
Author(s):  
Nickolay K. Isaev ◽  
Elena V. Stelmashook ◽  
Elisaveta E. Genrikhs ◽  
Galina A. Korshunova ◽  
Natalya V. Sumbatyan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Area ◽  
Hippocampal Slices ◽  
Amyloid Β ◽  
Long Term Potentiation ◽  
Term Potentiation ◽  
Neuroprotective Action

AbstractIn 2008, using a model of compression brain ischemia, we presented the first evidence that mitochondria-targeted antioxidants of the SkQ family, i.e. SkQR1 [10-(6′-plastoquinonyl)decylrhodamine], have a neuroprotective action. It was shown that intraperitoneal injections of SkQR1 (0.5–1 μmol/kg) 1 day before ischemia significantly decreased the damaged brain area. Later, we studied in more detail the anti-ischemic action of this antioxidant in a model of experimental focal ischemia provoked by unilateral intravascular occlusion of the middle cerebral artery. The neuroprotective action of SkQ family compounds (SkQR1, SkQ1, SkQTR1, SkQT1) was manifested through the decrease in trauma-induced neurological deficit in animals and prevention of amyloid-β-induced impairment of long-term potentiation in rat hippocampal slices. At present, most neurophysiologists suppose that long-term potentiation underlies cellular mechanisms of memory and learning. They consider inhibition of this process by amyloid-β1-42as anin vitromodel of memory disturbance in Alzheimer’s disease. Further development of the above studies revealed that mitochondria-targeted antioxidants could retard accumulation of hyperphosphorylated τ-protein, as well as amyloid-β1-42, and its precursor APP in the brain, which are involved in developing neurodegenerative processes in Alzheimer’s disease.

scholarly journals Amyloid-β protein modulates the perivascular clearance of neuronal apolipoprotein E in mouse models of Alzheimer’s disease

2011 ◽  
Vol 118 (5) ◽  
pp. 699-712 ◽  
Author(s):  
Harshvardhan Rolyan ◽  
Ann Caroline Feike ◽  
Ajeet Rijal Upadhaya ◽  
Andreas Waha ◽  
Tom Van Dooren ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Apolipoprotein E ◽  
Mouse Models ◽  
Amyloid Β ◽  
Amyloid Β Protein ◽  
Β Protein

Reduced amyloid-β degradation in early Alzheimer's disease but not in the APPswePS1dE9 and 3xTg-AD mouse models

Aging Cell ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 499-507 ◽  
Author(s):  
Anita Stargardt ◽  
Judith Gillis ◽  
Willem Kamphuis ◽  
Anne Wiemhoefer ◽  
Lieneke Kooijman ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Amyloid Β ◽  
Early Alzheimer’S Disease

scholarly journals Ageing-associated myelin dysfunction drives amyloid deposition in mouse models of Alzheimer's disease

2021 ◽  
Author(s):  
Constanze Depp ◽  
Ting Sun ◽  
Andrew Octavian Sasmita ◽  
Lena Spieth ◽  
Stefan A. Berghoff ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Risk Factor ◽  
Mouse Models ◽  
Structural Integrity ◽  
Amyloid Β ◽  
Amyloid Deposition ◽  
Structural Defects ◽  
Light Sheet Microscopy ◽  
Brain Ageing

The prevalence of Alzheimer's disease (AD), the leading cause of dementia, shows a strict age-dependency, but why ageing constitutes the main risk factor for this disease is still poorly understood. Brain ageing affects oligodendrocytes and the structural integrity of myelin sheaths, the latter associated with secondary neuroinflammation. Since oligodendrocytes support axonal and neuronal health, we hypothesised that ageing-associated loss of myelin integrity could be an upstream risk factor for neuronal amyloid-β (Aβ) deposition, the primary neuropathological hallmark of AD. Here, we show that in AD mouse models different genetically induced defects of myelin integrity or demyelinating injuries are indeed potent drivers of amyloid deposition in vivo, quantified by whole brain light sheet microscopy. Conversely, the lack of myelin in the forebrain provides protection against plaque deposition. Mechanistically, we find that myelin dysfunction causes the accumulation of the Aβ producing machinery within axonal swellings and increases cortical amyloid precursor protein (APP) cleavage. Surprisingly, AD mice with dysfunctional myelin lack plaque-corralling microglia but show a disease-associated microglia (DAM)-like signature as revealed by bulk and single cell transcriptomics. These activated microglia, however, are primarily engaged with myelin, preventing the protective reactions of microglia to Aβ plaques. Our data suggest a working model, in which age-dependent structural defects of myelin promote plaque formation, directly and indirectly, and are thus an upstream AD risk factor. Improving oligodendrocyte health and myelin integrity could be a promising target to delay AD.

scholarly journals Programmed Cell Death Protein 1 Blockade Reduces Glycogen Synthase Kinase 3β Activity and Tau Hyperphosphorylation in Alzheimer’s Disease Mouse Models

2021 ◽  
Vol 9 ◽  
Author(s):  
Yulian Zou ◽  
Chen-Ling Gan ◽  
Zhiming Xin ◽  
Hai-Tao Zhang ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Mouse Models ◽  
Glycogen Synthase ◽  
Neuronal Damage ◽  
Amyloid Β ◽  
Glycogen Synthase Kinase ◽  
Tau Hyperphosphorylation

Alzheimer’s disease (AD) is a central nervous system degenerative disease, with no effective treatment to date. Administration of immune checkpoint inhibitors significantly reduces neuronal damage and tau hyperphosphorylation in AD, but the specific mechanism is unclear. Here, we found that programmed cell death-receptor 1 (PD1) and its ligand PDL1 were induced by an intracerebroventricular injection of amyloid-β; they were significantly upregulated in the brains of APP/PS1, 5×FAD mice and in SH-SY5Y-APP cell line compared with control. The PD1 and PDL1 levels positively correlated with the glycogen synthase kinase 3 beta (GSK3β) activity in various AD mouse models, and the PDL1-GSK3β immune complex was found in the brain. The application of PD1-blocking antibody reduced tau hyperphosphorylation and GSK3β activity and prevented memory impairments. Mechanistically, we identified PD1 as a critical regulator of GSK3β activity. These results suggest that the immune regulation of the PD1/PDL1 axis is closely involved in AD.

scholarly journals Alzheimer’s-like pathology in aging rhesus macaques: Unique opportunity to study the etiology and treatment of Alzheimer’s disease

2019 ◽  
Vol 116 (52) ◽  
pp. 26230-26238 ◽  
Author(s):  
Amy F. T. Arnsten ◽  
Dibyadeep Datta ◽  
Shannon Leslie ◽  
Sheng-Tao Yang ◽  
Min Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Immunoelectron Microscopy ◽  
Rhesus Monkeys ◽  
Early Stage ◽  
Amyloid Β ◽  
Tau Phosphorylation ◽  
Association Cortex ◽  
Tau Pathology

Although mouse models of Alzheimer’s disease (AD) have provided tremendous breakthroughs, the etiology of later onset AD remains unknown. In particular, tau pathology in the association cortex is poorly replicated in mouse models. Aging rhesus monkeys naturally develop cognitive deficits, amyloid plaques, and the same qualitative pattern and sequence of tau pathology as humans, with tangles in the oldest animals. Thus, aging rhesus monkeys can play a key role in AD research. For example, aging monkeys can help reveal how synapses in the prefrontal association cortex are uniquely regulated compared to the primary sensory cortex in ways that render them vulnerable to calcium dysregulation and tau phosphorylation, resulting in the selective localization of tau pathology observed in AD. The ability to assay early tau phosphorylation states and perform high-quality immunoelectron microscopy in monkeys is a great advantage, as one can capture early-stage degeneration as it naturally occurs in situ. Our immunoelectron microscopy studies show that phosphorylated tau can induce an “endosomal traffic jam” that drives amyloid precursor protein cleavage to amyloid-β in endosomes. As amyloid-β increases tau phosphorylation, this creates a vicious cycle where varied precipitating factors all lead to a similar phenotype. These data may help explain why circuits with aggressive tau pathology (e.g., entorhinal cortex) may degenerate prior to producing significant amyloid pathology. Aging monkeys therefore can play an important role in identifying and testing potential therapeutics to protect the association cortex, including preventive therapies that are challenging to test in humans.

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