scholarly journals Bupropion and Citalopram in the APP23 Mouse Model of Alzheimer's Disease: A Study in a Dry-Land Maze

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Katharina L. Neumeister ◽  
Matthias W. Riepe

Background. Incipient Alzheimer's disease is often disguised as depressive disorder. Over the course of AD, depressive symptoms are even more frequent. Hence, treatment with antidepressants is common in AD. It was the goal of the present study to assess whether two common antidepressants with different mechanisms of action affect spatial learning in a transgenic animal model of Alzheimer's disease.Methods. We assessed spatial memory of male wild-type and B6C3-Tg(APPswe,PSEN1dE9)85Dbo (APP23) transgenic animals in a complex dry-land maze. Animals were treated with citalopram (10 mg/kg) and bupropion (20 mg/kg).Results. Moving and resting time until finding the goal zone decreased in 4.5-month-old sham-treated wild-type animals and, to a lesser extent, in APP23 animals. Compared with sham-treated APP23 animals, treatment with bupropion reduced resting time and increased speed. On treatment with citalopram, moving and resting time were unchanged but speed decreased. Length of the path to the goal zone did not change on either bupropion or citalopram.Conclusion. Bupropion increases psychomotor activity in APP23 transgenic animals, while citalopram slightly reduces psychomotor activity. Spatial learning per se is unaffected by treatment with either bupropion or citalopram.

2021 ◽  
Vol 14 (12) ◽  
pp. 1218
Author(s):  
Christian Viel ◽  
Adrian T. Brandtner ◽  
Alexander Weißhaar ◽  
Alina Lehto ◽  
Marius Fuchs ◽  
...  

Glucose hypometabolism, mitochondrial dysfunction, and cholinergic deficits have been reported in early stages of Alzheimer’s disease (AD). Here, we examine these parameters in TgF344-AD rats, an Alzheimer model that carries amyloid precursor protein and presenilin-1 mutations, and of wild type F344 rats. In mitochondria isolated from rat hippocampi, we found reductions of complex I and oxidative phosphorylation in transgenic rats. Further impairments, also of complex II, were observed in aged (wild-type and transgenic) rats. Treatment with a “cocktail” containing magnesium orotate, benfotiamine, folic acid, cyanocobalamin, and cholecalciferol did not affect mitochondrial activities in wild-type rats but restored diminished activities in transgenic rats to wild-type levels. Glucose, lactate, and pyruvate levels were unchanged by age, genetic background, or treatment. Using microdialysis, we also investigated extracellular concentrations of acetylcholine that were strongly reduced in transgenic animals. Again, ACh levels in wild-type rats did not change upon treatment with nutrients, whereas the cocktail increased hippocampal acetylcholine levels under physiological stimulation. We conclude that TgF344-AD rats display a distinct mitochondrial and cholinergic dysfunction not unlike the findings in patients suffering from AD. This dysfunction can be partially corrected by the application of the “cocktail” which is particularly active in aged rats. We suggest that the TgF344-AD rat is a promising model to further investigate mitochondrial and cholinergic dysfunction and potential treatment approaches for AD.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Nicola Davis ◽  
Bibiana C. Mota ◽  
Larissa Stead ◽  
Emily O. C. Palmer ◽  
Laura Lombardero ◽  
...  

Abstract Background Astrocytes provide a vital support to neurons in normal and pathological conditions. In Alzheimer’s disease (AD) brains, reactive astrocytes have been found surrounding amyloid plaques, forming an astrocytic scar. However, their role and potential mechanisms whereby they affect neuroinflammation, amyloid pathology, and synaptic density in AD remain unclear. Methods To explore the role of astrocytes on Aβ pathology and neuroinflammatory markers, we pharmacologically ablated them in organotypic brain culture slices (OBCSs) from 5XFAD mouse model of AD and wild-type (WT) littermates with the selective astrocytic toxin L-alpha-aminoadipate (L-AAA). To examine the effects on synaptic circuitry, we measured dendritic spine number and size in OBCSs from Thy-1-GFP transgenic mice incubated with synthetic Aβ42 or double transgenics Thy-1-GFP/5XFAD mice treated with LAAA or vehicle for 24 h. Results Treatment of OBCSs with L-AAA resulted in an increased expression of pro-inflammatory cytokine IL-6 in conditioned media of WTs and 5XFAD slices, associated with changes in microglia morphology but not in density. The profile of inflammatory markers following astrocytic loss was different in WT and transgenic cultures, showing reductions in inflammatory mediators produced in astrocytes only in WT sections. In addition, pharmacological ablation of astrocytes led to an increase in Aβ levels in homogenates of OBCS from 5XFAD mice compared with vehicle controls, with reduced enzymatic degradation of Aβ due to lower neprilysin and insulin-degrading enzyme (IDE) expression. Furthermore, OBSCs from wild-type mice treated with L-AAA and synthetic amyloid presented 56% higher levels of Aβ in culture media compared to sections treated with Aβ alone, concomitant with reduced expression of IDE in culture medium, suggesting that astrocytes contribute to Aβ clearance and degradation. Quantification of hippocampal dendritic spines revealed a reduction in their density following L-AAA treatment in all groups analyzed. In addition, pharmacological ablation of astrocytes resulted in a decrease in spine size in 5XFAD OBCSs but not in OBCSs from WT treated with synthetic Aβ compared to vehicle control. Conclusions Astrocytes play a protective role in AD by aiding Aβ clearance and supporting synaptic plasticity.


2010 ◽  
Vol 6 ◽  
pp. S225-S225
Author(s):  
Chia-Yu Yeh ◽  
Markel Olabarria ◽  
Harun N. Noristani ◽  
Alexei Verkhratsky ◽  
Jose J. Rodriguez

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Junkai Hu ◽  
Stanley Li Lin ◽  
Melitta Schachner

AbstractDeposition of amyloid-β (Aβ) in the brain is one of the important histopathological features of Alzheimer’s disease (AD). Previously, we reported a correlation between cell adhesion molecule L1 (L1) expression and the occurrence of AD, but its relationship was unclear. Here, we report that the expression of L1 and a 70 kDa cleavage product of L1 (L1-70) was reduced in the hippocampus of AD (APPswe) mice. Interestingly, upregulation of L1-70 expression in the hippocampus of 18-month-old APPswe mice, by parabiosis involving the joining of the circulatory system of an 18-month-old APPswe mouse with a 2-month-old wild-type C57BL/6 mouse, reduced amyloid plaque deposition. Furthermore, the reduction was accompanied by the appearance of a high number of activated microglia. Mechanistically, we observed that L1-70 could combine with topoisomerase 1 (Top1) to form a complex, L1-70/Top1, that was able to regulate expression of macrophage migration inhibitory factor (MIF), resulting in the activation of microglia and reduction of Aβ plaques. Also, transforming growth factor β1 (TGFβ-1) transferred from the blood of young wild-type C57BL/6 mice to the aged AD mice, was identified as a circulating factor that induces full-length L1 and L1-70 expression. All together, these findings suggest that L1-70 contributes to the clearance of Aβ in AD, thereby adding a novel perspective in understanding AD pathogenesis.


2021 ◽  
Author(s):  
Swati Som ◽  
Justin Antony ◽  
Palanisamy Dhanabal ◽  
Ponnusankar Sivasankaran

Abstract Diosgenin is a neurosteroid derived from the plants and has been previously reported for its numerous health beneficial properties, such as anti-arrhythmic, hypolipidemic, and antiproliferative effects. Although several studies conducted earlier suggested cognition enhancement actions of diosgenin against neurodegenerative disorders, but the molecular mechanisms underlying are not clearly understood. In the present study, we investigated the neuroprotective effect of diosgenin in the wistar rats that received an intracerebroventricular injection of Amyloid-β (1–42) peptides, representing a rodent model of Alzheimer’s disease (AD). Animals were treated with 100 and 200 mg/kg/p.o of diosgenin for 28 days, followed by Amyloid-β (1–42) peptides infusion. Animals were assessed for the spatial learning and memory by using radial arm maze and passive avoidance task. Subsequently, animals were euthanized and brains were collected for biochemical estimations and histopathological studies. Our results revealed that, diosgenin administration dose dependently improved the spatial learning and memory and protected the animals from Amyloid-β (1–42) peptides induced disrupted cognitive functions. Further, biochemical analysis showed that diosgenin successfully attenuated Amyloid-β (1–42) mediated plaque load, oxidative stress, neuroinflammation and elevated acetylcholinesterase activity. In addition, histopathological evaluation also supported neuroprotective effects of diosgenin in hippocampus of rat brain when assessed using hematoxylin-eosin and Cresyl Violet staining. Thus, the aforementioned effects suggested protective action of diosgenin against Aβ (1–42) induced neuronal damage and thereby can serve as a potential therapeutic candidate for AD.


2006 ◽  
Vol 14 (7S_Part_20) ◽  
pp. P1089-P1089
Author(s):  
Roland Rabl ◽  
Stephan Kurat ◽  
Iera Hernandez ◽  
Estibaliz Santiago-Mugica ◽  
Stefanie Flunkert ◽  
...  

2011 ◽  
Vol 39 (4) ◽  
pp. 868-873 ◽  
Author(s):  
Eva Borger ◽  
Laura Aitken ◽  
Kirsty E.A. Muirhead ◽  
Zoe E. Allen ◽  
James A. Ainge ◽  
...  

It is well established that the intracellular accumulation of Aβ (amyloid β-peptide) is associated with AD (Alzheimer's disease) and that this accumulation is toxic to neurons. The precise mechanism by which this toxicity occurs is not well understood; however, identifying the causes of this toxicity is an essential step towards developing treatments for AD. One intracellular location where the accumulation of Aβ can have a major effect is within mitochondria, where mitochondrial proteins have been identified that act as binding sites for Aβ, and when binding occurs, a toxic response results. At one of these identified sites, an enzyme known as ABAD (amyloid-binding alcohol dehydrogenase), we have identified changes in gene expression in the brain cortex, following Aβ accumulation within mitochondria. Specifically, we have identified two proteins that are up-regulated not only in the brains of transgenic animal models of AD but also in those of human sufferers. The increased expression of these proteins demonstrates the complex and counteracting pathways that are activated in AD. Previous studies have identified approximate contact sites between ABAD and Aβ; on basis of these observations, we have shown that by using a modified peptide approach it is possible to reverse the expression of these two proteins in living transgenic animals and also to recover mitochondrial and behavioural deficits. This indicates that the ABAD–Aβ interaction is potentially an interesting target for therapeutic intervention. To explore this further we used a fluorescing substrate mimic to measure the activity of ABAD within living cells, and in addition we have identified chemical fragments that bind to ABAD, using a thermal shift assay.


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