scholarly journals Longitudinal Assessment of Working Memory Performance in the APPswe/PSEN1dE9 Mouse Model of Alzheimer’s Disease Using an Automated Figure-8-Maze

2021 ◽  
Vol 15 ◽  
Author(s):  
Fran C. van Heusden ◽  
Sara Palacín i Bonsón ◽  
Oliver Stiedl ◽  
August B. Smit ◽  
Ronald E. van Kesteren
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Functioning ◽  
Acute Stress ◽  
Neurodegenerative Disorder ◽  
Memory Performance ◽  
Longitudinal Assessment ◽  
Experimental Conditions ◽  
Prodromal Phase ◽  
Model Of Alzheimer’S Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, with a long preclinical and prodromal phase. To enable the study of disease mechanisms, AD has been modeled in many transgenic animal lines and cognitive functioning has been tested using several widely used behavioral tasks. These tasks, however, are not always suited for repeated longitudinal testing and are often associated with acute stress such as animal transfer, handling, novelty, or stress related to the task itself. This makes it challenging to relate cognitive dysfunction in animal models to cognitive decline observed in AD patients. Here, we designed an automated figure-8-maze (F8M) to test mice in a delayed alternation task (DAT) in a longitudinal manner. Mice were rewarded when they entered alternate sides of the maze on subsequent trials. Automation as well as connection of the F8M set-up with a home cage reduces experimenter interference and minimizes acute stress, thus making it suitable for longitudinal testing and facilitating clinical translation. In the present study, we monitored cognitive functioning of 2-month-old APPswe/PSEN1dE9 (APP/PS1) mice over a period of 4 months. The percentage of correct responses in the DAT did not differ between wild-type and transgenic mice from 2 to 6 months of age. However, 6-month-old mice displayed an increase in the number of consecutive incorrect responses. These results demonstrate the feasibility of longitudinal testing using an automated F8M and suggest that APP/PS1 mice are not impaired at delayed spatial alternation until 6 months of age under the current experimental conditions.

scholarly journals Brain energy metabolism in intracerebroventricularly administered streptozotocin mouse model of Alzheimer’s disease: A 1H-[13C]-NMR study

2021 ◽  
pp. 0271678X2199617
Author(s):  
Narayan D Soni ◽  
Akila Ramesh ◽  
Dipak Roy ◽  
Anant B Patel
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Glucose Oxidation ◽  
Neurodegenerative Disorder ◽  
Nmr Spectrum ◽  
Tissue Extracts ◽  
Model Of Alzheimer’S Disease ◽  
Nmr Study ◽  
Synaptic Neurotransmission ◽  
C Nmr

Alzheimer’s disease (AD) is a very common neurodegenerative disorder. Although a majority of the AD cases are sporadic, most of the studies are conducted using transgenic models. Intracerebroventricular (ICV) administered streptozotocin (STZ) animals have been used to explore mechanisms in sporadic AD. In this study, we have investigated memory and neurometabolism of ICV-STZ-administered C57BL6/J mice. The neuronal and astroglial metabolic activity was measured in 1H-[13C]-NMR spectrum of cortical and hippocampal tissue extracts of mice infused with [1,6-13C2]glucose and [2-13C]acetate, respectively. STZ-administered mice exhibited reduced (p = 0.00002) recognition index for memory. The levels of creatine, GABA, glutamate and NAA were reduced (p ≤ 0.04), while that of myo-inositol was increased (p < 0.05) in STZ-treated mice. There was a significant (p ≤ 0.014) reduction in aspartate-C3, glutamate-C4/C3, GABA-C2 and glutamine-C4 labeling from [1,6-13C2]glucose. This resulted in decreased rate of glucose oxidation in the cerebral cortex (0.64 ± 0.05 vs. 0.77 ± 0.05 µmol/g/min, p = 0.0008) and hippocampus (0.60 ± 0.04 vs. 0.73 ± 0.07 µmol/g/min, p = 0.001) of STZ-treated mice, due to similar reductions of glucose oxidation in glutamatergic and GABAergic neurons. Additionally, reduced glutamine-C4 labeling points towards compromised synaptic neurotransmission in STZ-treated mice. These data suggest that the ICV-STZ model exhibits neurometabolic deficits typically observed in AD, and its utility in understanding the mechanism of sporadic AD.

scholarly journals Torpor enhances synaptic strength and restores memory performance in a mouse model of Alzheimer’s disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina F. de Veij Mestdagh ◽  
Jaap A. Timmerman ◽  
Frank Koopmans ◽  
Iryna Paliukhovich ◽  
Suzanne S. M. Miedema ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Memory Performance ◽  
Long Term Potentiation ◽  
Fear Memory ◽  
Contextual Fear ◽  
Contextual Fear Memory ◽  
Model Of Alzheimer’S Disease ◽  
Term Potentiation

AbstractHibernation induces neurodegeneration-like changes in the brain, which are completely reversed upon arousal. Hibernation-induced plasticity may therefore be of great relevance for the treatment of neurodegenerative diseases, but remains largely unexplored. Here we show that a single torpor and arousal sequence in mice does not induce dendrite retraction and synapse loss as observed in seasonal hibernators. Instead, it increases hippocampal long-term potentiation and contextual fear memory. This is accompanied by increased levels of key postsynaptic proteins and mitochondrial complex I and IV proteins, indicating mitochondrial reactivation and enhanced synaptic plasticity upon arousal. Interestingly, a single torpor and arousal sequence was also sufficient to restore contextual fear memory in an APP/PS1 mouse model of Alzheimer’s disease. Our study demonstrates that torpor in mice evokes an exceptional state of hippocampal plasticity and that naturally occurring plasticity mechanisms during torpor provide an opportunity to identify unique druggable targets for the treatment of cognitive impairment.

scholarly journals Altered Theta Oscillations and Aberrant Cortical Excitatory Activity in the 5XFAD Model of Alzheimer’s Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Magdalena Elisabeth Siwek ◽  
Ralf Müller ◽  
Christina Henseler ◽  
Astrid Trog ◽  
Andreas Lundt ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Cortical Excitability ◽  
Theta Oscillations ◽  
Dark Phase ◽  
Model Of Alzheimer’S Disease ◽  
Cortical Hyperexcitability ◽  
5Xfad Mice ◽  
Hippocampal Theta

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder characterized by impairment of memory function. The 5XFAD mouse model was analyzed and compared with wild-type (WT) controls for aberrant cortical excitability and hippocampal theta oscillations by using simultaneous video-electroencephalogram (EEG) monitoring. Seizure staging revealed that 5XFAD mice exhibited cortical hyperexcitability whereas controls did not. In addition, 5XFAD mice displayed a significant increase in hippocampal theta activity from the light to dark phase during nonmotor activity. We also observed a reduction in mean theta frequency in 5XFAD mice compared to controls that was again most prominent during nonmotor activity. Transcriptome analysis of hippocampal probes and subsequent qPCR validation revealed an upregulation of Plcd4 that might be indicative of enhanced muscarinic signalling. Our results suggest that 5XFAD mice exhibit altered cortical excitability, hippocampal dysrhythmicity, and potential changes in muscarinic signaling.

scholarly journals Prostacyclin Promotes Degenerative Pathology in a Model of Alzheimer’s disease

2020 ◽  
Author(s):  
Tasha R. Womack ◽  
Craig Vollert ◽  
Odochi Nwoko ◽  
Monika Schmitt ◽  
Sagi Montazari ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Amyloid Β ◽  
Chronic Neuroinflammation ◽  
Model Of Alzheimer’S Disease ◽  
Amyloid Accumulation ◽  
Prostaglandin H ◽  
The Brain

AbstractAlzheimer’s disease (AD) is a progressive neurodegenerative disorder that is the most common cause of dementia in aged populations. A substantial amount of data demonstrates that chronic neuroinflammation can accelerate neurodegenerative pathologies, while epidemiological and experimental evidence suggests that the use of anti-inflammatory agents may be neuroprotective. In AD, chronic neuroinflammation results in the upregulation of cyclooxygenase and increased production of prostaglandin H2, a precursor for many vasoactive prostanoids. While it is well-established that many prostaglandins can modulate the progression of neurodegenerative disorders, the role of prostacyclin (PGI2) in the brain is poorly understood. We have conducted studies to assess the effect of elevated prostacyclin biosynthesis in a mouse model of AD. Upregulated prostacyclin expression significantly worsened multiple measures associated with amyloid disease pathologies. Mice overexpressing both amyloid and PGI2 exhibited impaired learning and memory and increased anxiety-like behavior compared with non-transgenic and PGI2 control mice. PGI2 overexpression accelerated the development of amyloid accumulation in the brain and selectively increased the production of soluble amyloid-β 42. PGI2 damaged the microvasculature through alterations in vascular length and branching; amyloid expression exacerbated these effects. Our findings demonstrate that chronic prostacyclin expression plays a novel and unexpected role that hastens the development of the AD phenotype.

NAD+ supplementation reduces neuroinflammation and cell senescence in a transgenic mouse model of Alzheimer’s disease via cGAS–STING

2021 ◽  
Vol 118 (37) ◽  
pp. e2011226118
Author(s):  
Yujun Hou ◽  
Yong Wei ◽  
Sofie Lautrup ◽  
Beimeng Yang ◽  
Yue Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dna Damage ◽  
Cellular Senescence ◽  
Neurodegenerative Disorder ◽  
Mutant Mice ◽  
Beneficial Effects ◽  
Markers Of Inflammation ◽  
Model Of Alzheimer’S Disease ◽  
Synaptic Functions

Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder. Impaired neuronal bioenergetics and neuroinflammation are thought to play key roles in the progression of AD, but their interplay is not clear. Nicotinamide adenine dinucleotide (NAD+) is an important metabolite in all human cells in which it is pivotal for multiple processes including DNA repair and mitophagy, both of which are impaired in AD neurons. Here, we report that levels of NAD+ are reduced and markers of inflammation increased in the brains of APP/PS1 mutant transgenic mice with beta-amyloid pathology. Treatment of APP/PS1 mutant mice with the NAD+ precursor nicotinamide riboside (NR) for 5 mo increased brain NAD+ levels, reduced expression of proinflammatory cytokines, and decreased activation of microglia and astrocytes. NR treatment also reduced NLRP3 inflammasome expression, DNA damage, apoptosis, and cellular senescence in the AD mouse brains. Activation of cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) are associated with DNA damage and senescence. cGAS–STING elevation was observed in the AD mice and normalized by NR treatment. Cell culture experiments using microglia suggested that the beneficial effects of NR are, in part, through a cGAS–STING-dependent pathway. Levels of ectopic (cytoplasmic) DNA were increased in APP/PS1 mutant mice and human AD fibroblasts and down-regulated by NR. NR treatment induced mitophagy and improved cognitive and synaptic functions in APP/PS1 mutant mice. Our findings suggest a role for NAD+ depletion-mediated activation of cGAS–STING in neuroinflammation and cellular senescence in AD.

scholarly journals CNI-1493 inhibits Aβ production, plaque formation, and cognitive deterioration in an animal model of Alzheimer's disease

2008 ◽  
Vol 205 (7) ◽  
pp. 1593-1599 ◽  
Author(s):  
Michael Bacher ◽  
Richard Dodel ◽  
Bayan Aljabari ◽  
Kathy Keyvani ◽  
Philippe Marambaud ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Performance ◽  
Amyloid Β ◽  
Amyloid Plaque ◽  
Amyloid Β Protein ◽  
Aβ Oligomers ◽  
App Processing ◽  
Model Of Alzheimer’S Disease

Alzheimer's disease (AD) is characterized by neuronal atrophy caused by soluble amyloid β protein (Aβ) peptide “oligomers” and a microglial-mediated inflammatory response elicited by extensive amyloid deposition in the brain. We show that CNI-1493, a tetravalent guanylhydrazone with established antiinflammatory properties, interferes with Aβ assembly and protects neuronal cells from the toxic effect of soluble Aβ oligomers. Administration of CNI-1493 to TgCRND8 mice overexpressing human amyloid precursor protein (APP) for a treatment period of 8 wk significantly reduced Aβ deposition. CNI-1493 treatment resulted in 70% reduction of amyloid plaque area in the cortex and 87% reduction in the hippocampus of these animals. Administration of CNI-1493 significantly improved memory performance in a cognition task compared with vehicle-treated mice. In vitro analysis of CNI-1493 on APP processing in an APP-overexpressing cell line revealed a significant dose-dependent decrease of total Aβ accumulation. This study indicates that the antiinflammatory agent CNI-1493 can ameliorate the pathophysiology and cognitive defects in a murine model of AD.

scholarly journals The Moringin/α-CD Pretreatment Induces Neuroprotection in an In Vitro Model of Alzheimer’s Disease: A Transcriptomic Study

2021 ◽  
Vol 43 (1) ◽  
pp. 197-214
Author(s):  
Serena Silvestro ◽  
Luigi Chiricosta ◽  
Agnese Gugliandolo ◽  
Renato Iori ◽  
Patrick Rollin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
In Vitro Model ◽  
Neurodegenerative Disorder ◽  
Senile Dementia ◽  
Neuroprotective Effects ◽  
Model Of Alzheimer’S Disease ◽  
Vitro Model ◽  
Ad Prevention

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and represents the most common form of senile dementia. Autophagy and mitophagy are cellular processes that play a key role in the aggregation of β-amyloid (Aβ) and tau phosphorylation. As a consequence, impairment of these processes leads to the progression of AD. Thus, interest is growing in the search for new natural compounds, such as Moringin (MOR), with neuroprotective, anti-amyloidogenic, antioxidative, and anti-inflammatory properties that could be used for AD prevention. However, MOR appears to be poorly soluble and stable in water. To increase its solubility MOR was conjugated with α-cyclodextrin (MOR/α-CD). In this work, it was evaluated if MOR/α-CD pretreatment was able to exert neuroprotective effects in an AD in vitro model through the evaluation of the transcriptional profile by next-generation sequencing (NGS). To induce the AD model, retinoic acid-differentiated SH-SY5Y cells were exposed to Aβ1-42. The MOR/α-CD pretreatment reduced the expression of the genes which encode proteins involved in senescence, autophagy, and mitophagy processes. Additionally, MOR/α-CD was able to induce neuronal remodeling modulating the axon guidance, principally downregulating the Slit/Robo signaling pathway. Noteworthy, MOR/α-CD, modulating these important pathways, may induce neuronal protection against Aβ1-42 toxicity as demonstrated also by the reduction of cleaved caspase 3. These data indicated that MOR/α-CD could attenuate the progression of the disease and promote neuronal repair.

scholarly journals Disruption of Glucose Metabolism in Aged Octodon degus: A Sporadic Model of Alzheimer's Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Pedro Cisternas ◽  
Camila Gherardelli ◽  
Paulina Salazar ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Neurodegenerative Disorder ◽  
Hippocampal Slices ◽  
Amyloid Β ◽  
High Energy ◽  
Octodon Degus ◽  
Model Of Alzheimer’S Disease

Alzheimer's disease is a progressive neurodegenerative disorder and the most common cause of dementia. Although transgenic Alzheimer's disease (AD) animal models have greatly contributed to our understanding of the disease, therapies tested in these animals have resulted in a high rate of failure in preclinical trials for AD. A promising model is Octodon degus (degu), a Chilean rodent that spontaneously develops AD-like neuropathology. Previous studies have reported that, during aging, degus exhibit a progressive decline in cognitive function, reduced neuroinflammation, and concomitant increases in the number and size of amyloid β (Aβ) plaques in several brain regions. Importantly, in humans and several AD models, a correlation has been shown between brain dysfunction and neuronal glucose utilization impairment, a critical aspect considering the high-energy demand of the brain. However, whether degus develop alterations in glucose metabolism remains unknown. In the present work, we measured several markers of glucose metabolism, namely, glucose uptake, ATP production, and glycolysis and pentose phosphate pathway (PPP) flux, in hippocampal slices from degus of different ages. We found a significant decrease in hippocampal glucose metabolism in aged degus, caused mainly by a drop in glucose uptake, which in turn, reduced ATP synthesis. Moreover, we observed a negative correlation between age and PPP flux. Together, our data further support the use of degus as a model for studying the neuropathology involved in sporadic AD-like pathology and as a potentially valuable tool in the search for effective treatments against the disease.

scholarly journals Naphthalene monoimide derivative ameliorates amyloid burden and cognitive decline in a transgenic mouse model of Alzheimer’s disease

2020 ◽  
Author(s):  
Sourav Samanta ◽  
Kolla Rajasekhar ◽  
Madhu Ramesh ◽  
N. Arul Murugan ◽  
Shadab Alam ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Deficits ◽  
Neurodegenerative Disorder ◽  
Amyloid Β ◽  
Salt Bridges ◽  
Amyloid Burden ◽  
Amyloid Toxicity ◽  
Model Of Alzheimer’S Disease

ABSTRACTAlzheimer’s disease (AD) is a major neurodegenerative disorder and the leading cause of dementia worldwide. Predominantly, misfolding and aggregation of amyloid-β (Aβ) peptides associated with multifaceted toxicity is the neuropathological hallmark of AD pathogenesis and thus, primary therapeutic target to ameliorate neuronal toxicity and cognitive deficits. Herein, we report the design, synthesis and evaluation of small molecule inhibitors with naphthalene monoimide scaffold to ameliorate in vitro and in vivo amyloid induced neurotoxicity. The detailed studies established TGR63 as the lead candidate to rescue neuronal cells from amyloid toxicity. The in silico studies showed disruption of salt bridges and intermolecular hydrogen bonding interactions within Aβ42 fibrils by the interaction of TGR63, causing destabilization of Aβ42 assembly. Remarkably, TGR63 treatment showed a significant reduction in cortical and hippocampal amyloid burden in the progressive stages of APP/PS1 AD mice brain. Various behavioral tests demonstrated rescued cognitive deficits. The excellent biocompatibility, BBB permeability and therapeutic efficacy to reduce amyloid burden make TGR63 a promising candidate for the treatment of AD.

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