Adiponectin Ameliorates Cognitive Behaviors and in vivo Synaptic Plasticity Impairments in 3xTg-AD Mice

2021 ◽  
pp. 1-15
Author(s):  
Xu-Dong Yan ◽  
Xue-Song Qu ◽  
Jing Yin ◽  
Jin Qiao ◽  
Jun Zhang ◽  
...  

Background: Cognitive deficit is mainly clinical characteristic of Alzheimer’s disease (AD). Recent reports showed adiponectin and its analogues could reverse cognitive impairments, lower amyloid-β protein (Aβ) deposition, and exert anti-inflammatory effects in different APP/PS1 AD model mice mainly exhibiting amyloid plaque pathology. However, the potential in vivo electrophysiological mechanism of adiponectin protecting against cognitive deficits in AD and the neuroprotective effects of adiponectin on 3xTg-AD mice including both plaque and tangle pathology are still unclear. Objective: To observe the effects of adiponectin treatment on cognitive deficits in 3xTg-AD mice, investigate its potential in vivo electrophysiological mechanism, and testify its anti-inflammatory effects. Methods: Barnes maze test, Morris water maze test, and fear conditioning test were used to evaluate the memory-ameliorating effects of adiponectin on 3xTg-AD mice. In vivo hippocampal electrophysiological recording was used to observe the change of basic synaptic transmission, long-term potentiation, and long-term depression. Immunohistochemistry staining and western blot were used to observe the activation of microglia and astroglia, and the expression levels of proinflammatory factors and anti-inflammtory factor IL-10. Results: Adiponectin treatment could alleviate spatial memory and conditioned fear memory deficits observed in 3xTg-AD mice, improve in vivo LTP depression and LTD facilitation, inhibit overactivation of microglia and astroglia, decrease the expression of proinflammatory factors NF- κB and IL-1β, and increase the expression level of IL-10 in the hippocampus of 3xTg-AD mice. Conclusion: Adiponectin could ameliorate cognitive deficits in 3xTg-AD mice through improving in vivo synaptic plasticity impairments and alleviating neuroinflammation in the hippocampus of 3xTg-AD mice.

2021 ◽  
pp. 1-19
Author(s):  
Li Yuan ◽  
Jun Zhang ◽  
Jun-Hong Guo ◽  
Christian Holscher ◽  
Jun-Ting Yang ◽  
...  

Background: Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive decline in cognitive function. Type 2 diabetes mellitus (T2DM) is an important risk factor for AD. Glucose-dependent insulinotropic polypeptide (GIP) has been identified to be effective in T2DM treatment and neuroprotection. Objective: The present study investigated the neuroprotective effects and possible mechanisms of DAla2GIP-Glu-PAL, a novel long-lasting GIP analogue, in APP/PS1 AD mice. Methods: Multiple behavioral tests were performed to examine the cognitive function of mice. In vivo hippocampus late-phase long-term potentiation (L-LTP) was recorded to reflect synaptic plasticity. Immunohistochemistry and immunofluorescence were used to examine the Aβ plaques and neuroinflammation in the brain. IL-1β, TNF-α, and cAMP/PKA/CREB signal molecules were also detected by ELISA or western blotting. Results: DAla2GIP-Glu-PAL increased recognition index (RI) of APP/PS1 mice in novel object recognition test, elevated spontaneous alternation percentage of APP/PS1 mice in Y maze test, and increased target quadrant swimming time of APP/PS1 mice in Morris water maze test. DAla2GIP-Glu-PAL treatment enhanced in vivo L-LTP of APP/PS1 mice. DAla2GIP-Glu-PAL significantly reduced Aβ deposition, inhibited astrocyte and microglia proliferation, and weakened IL-1β and TNF-α secretion. DAla2GIP-Glu-PAL also upregulated cAMP/PKA/CREB signal transduction and inhibited NF-κB activation in the hippocampus of APP/PS1 mice. Conclusion: DAla2GIP-Glu-PAL can improve cognitive behavior, synaptic plasticity, and central pathological damage in APP/PS1 mice, which might be associated with the inhibition of neuroinflammation, as well as upregulation of cAMP-/PKA/CREB signaling pathway. This study suggests a potential benefit of DAla2GIP-Glu-PAL in the treatment of AD.


2020 ◽  
Vol 17 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Yu-Xing Ge ◽  
Ying-Ying Lin ◽  
Qian-Qian Bi ◽  
Yu-Juan Chen

Background: Patients with temporal lobe epilepsy (TLE) usually suffer from cognitive deficits and recurrent seizures. Brivaracetam (BRV) is a novel anti-epileptic drug (AEDs) recently used for the treatment of partial seizures with or without secondary generalization. Different from other AEDs, BRV has some favorable properties on synaptic plasticity. However, the underlying mechanisms remain elusive. Objective: The aim of this study was to explore the neuroprotective mechanism of BRV on synaptic plasticity in experimental TLE rats. Methods: The effect of chronic treatment with BRV (10 mg/kg) was assessed on Pilocarpine induced TLE model through measurement of the field excitatory postsynaptic potentials (fEPSPs) in vivo. Differentially expressed synaptic vesicle protein 2A (SV2A) were identified with immunoblot. Then, fast phosphorylation of synaptosomal-associated protein 25 (SNAP-25) during long-term potentiation (LTP) induction was performed to investigate the potential roles of BRV on synaptic plasticity in the TLE model. Results: An increased level of SV2A accompanied by a depressed LTP in the hippocampus was shown in epileptic rats. Furthermore, BRV treatment continued for more than 30 days improved the over-expression of SV2A and reversed the synaptic dysfunction in epileptic rats. Additionally, BRV treatment alleviates the abnormal SNAP-25 phosphorylation at Ser187 during LTP induction in epileptic ones, which is relevant to the modulation of synaptic vesicles exocytosis and voltagegated calcium channels. Conclusion: BRV treatment ameliorated the over-expression of SV2A in the hippocampus and rescued the synaptic dysfunction in epileptic rats. These results identify the neuroprotective effect of BRV on TLE model.


2019 ◽  
Vol 16 (8) ◽  
pp. 710-722 ◽  
Author(s):  
Xiao-Ying Sun ◽  
Quan-Xiu Dong ◽  
Jie Zhu ◽  
Xun Sun ◽  
Li-Fan Zhang ◽  
...  

Background: Alzheimer’s Disease (AD) is characterized by the presence of extracellular amyloid-β (Aβ) plaques and intraneuronal neurofibrillary tangles assembled by the microtubuleassociated protein tau. Increasing evidence demonstrated that tau pathology played an important role in AD progression. Resveratrol (RSV) has previously proved to exert neuroprotective effect against AD by inhibiting Aβ generation and Aβ-induced neurocytotoxicity, while its effect on tau pathology is still unknown. Method: The effect of RSV on tau aggregation was measured by Thioflavin T fluorescence and Transmission electron microscope imaging. The effect of RSV on tau oligomer-induced cytotoxicity was assessed by MTT assay and the uptake of extracellular tau by N2a cells was determined by immunocytochemistry. 6-month-old male PS19 mice were treated with RSV or vehicle by oral administration (gavage) once a day for 5 weeks. The cognitive performance was determined using Morris water maze test, object recognition test and Y-maze test. The levels of phosphorylated-tau, gliosis, proinflammatory cytokines such as TNF-α and IL-1β, and synaptic proteins including synaptophysin and PSD95 in the brains of the mice were evaluated by immunoblotting, immunostaining and ELISA, respectively. Results: RSV significantly inhibited tau aggregation and tau oligomer-induced cytotoxicity, and blocked the uptake of extracellular tau oligomers by N2a cells. When applied to PS19 mice, RSV treatment effectively rescued cognitive deficits, reducing the levels of phosphorylated tau, neuroinflammation and synapse loss in the brains of mice. Conclusion: These findings suggest that RSV has promising therapeutic potential for AD and other tauopathies.


2015 ◽  
Vol 210 (5) ◽  
pp. 771-783 ◽  
Author(s):  
Norbert Bencsik ◽  
Zsófia Szíber ◽  
Hanna Liliom ◽  
Krisztián Tárnok ◽  
Sándor Borbély ◽  
...  

Actin turnover in dendritic spines influences spine development, morphology, and plasticity, with functional consequences on learning and memory formation. In nonneuronal cells, protein kinase D (PKD) has an important role in stabilizing F-actin via multiple molecular pathways. Using in vitro models of neuronal plasticity, such as glycine-induced chemical long-term potentiation (LTP), known to evoke synaptic plasticity, or long-term depolarization block by KCl, leading to homeostatic morphological changes, we show that actin stabilization needed for the enlargement of dendritic spines is dependent on PKD activity. Consequently, impaired PKD functions attenuate activity-dependent changes in hippocampal dendritic spines, including LTP formation, cause morphological alterations in vivo, and have deleterious consequences on spatial memory formation. We thus provide compelling evidence that PKD controls synaptic plasticity and learning by regulating actin stability in dendritic spines.


Author(s):  
Mansi L. Patil ◽  
Swati S. Gaikwad ◽  
Naresh J. Gaikwad

Introduction: Pain is an immunological response to any infection or inflammation and long term use of pain management therapy includes use of Nonsteroidal anti-inflammatory drugs which is associated with occurrence of toxicity as well as gastrointestinal bleeding. Therefore, the investigation of new analgesic and anti-inflammatory agents remains a major challenge. Aims: The objective of this research study is to undergo the pharmacological evaluation of newly synthesized benzoxazole derivatives. These novel derivatives were evaluated for anti-nociceptive, anti-inflammatory and cytotoxic activity using various in-vivo and ex-vivo methods. Methods: The study was carried out using swiss mice (adult male) weighing between 20gm to 30gm and were divided into groups containing (n=6) six animals in each group for treatment. The anti-nociceptive activity was performed by using 0.1ml of 0.6% v/v acetic acid as nociception inducer and evaluated by the diminished number of abdominal writhes. The anti-inflammatory activity was done using 0.1 ml of 2% w/v Carrageenan induced paw edema method was observed which was evaluated by calculating the percent maximum possible effect. Histopathological evaluation and cytotoxic activity of the compounds was carried out. Results: The results of this research study revealed that synthesized derivatives (a, b, c, d and e) showed promising anti-nociceptive and anti-inflammatory effect along significantly higher cytotoxic activity in MCF-7 cell lines. Conclusion: It can be concluded that synthesized derivatives (a, b, c, d and e) have potential anti-nociceptive and anti-inflammatory effect along with cytotoxic activity and certain modification in structure may result in potent activity.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Feng ◽  
Chun-Xia Han ◽  
Shu-Yu Cao ◽  
He-Ming Zhang ◽  
Gang-Yi Wu

AbstractIschemic strokes cause devastating brain damage and functional deficits with few treatments available. Previous studies have shown that the ischemia-hypoxia rapidly induces clinically similar thrombosis and neuronal loss, but any resulting behavioral changes are largely unknown. The goal of this study was to evaluate motor and cognitive deficits in adult HI mice. Following a previously established procedure, HI mouse models were induced by first ligating the right common carotid artery and followed by hypoxia. Histological data showed significant long-term neuronal losses and reactive glial cells in the ipsilateral striatum and hippocampus of the HI mice. Whereas the open field test and the rotarod test could not reliably distinguish between the sham and HI mice, in the tapered beam and wire-hanging tests, the HI mice showed short-term and long-term deficits, as evidenced by the increased number of foot faults and decreased hanging time respectively. In cognitive tests, the HI mice swam longer distances and needed more time to find the platform in the Morris water maze test and showed shorter freezing time in fear contextual tests after fear training. In conclusion, this study demonstrates that adult HI mice have motor and cognitive deficits and could be useful models for preclinical stroke research.


Nature ◽  
2002 ◽  
Vol 420 (6917) ◽  
pp. 788-794 ◽  
Author(s):  
Joshua T. Trachtenberg ◽  
Brian E. Chen ◽  
Graham W. Knott ◽  
Guoping Feng ◽  
Joshua R. Sanes ◽  
...  

Nature ◽  
2002 ◽  
Vol 416 (6880) ◽  
pp. 535-539 ◽  
Author(s):  
Dominic M. Walsh ◽  
Igor Klyubin ◽  
Julia V. Fadeeva ◽  
William K. Cullen ◽  
Roger Anwyl ◽  
...  

2003 ◽  
Vol 358 (1432) ◽  
pp. 815-819 ◽  
Author(s):  
Mark J. Thomas ◽  
Robert C. Malenka

Long-term potentiation (LTP) and long-term depression (LTD) are thought to be critical mechanisms that contribute to the neural circuit modifications that mediate all forms of experience-dependent plasticity. It has, however, been difficult to demonstrate directly that experience causes long-lasting changes in synaptic strength and that these mediate changes in behaviour. To address these potential functional roles of LTP and LTD, we have taken advantage of the powerful in vivo effects of drugs of abuse that exert their behavioural effects in large part by acting in the nucleus accumbens (NAc) and ventral tegmental area (VTA); the two major components of the mesolimbic dopamine system. Our studies suggest that in vivo drugs of abuse such as cocaine cause long-lasting changes at excitatory synapses in the NAc and VTA owing to activation of the mechanisms that underlie LTP and LTD in these structures. Thus, administration of drugs of abuse provides a distinctive model for further investigating the mechanisms and functions of synaptic plasticity in brain regions that play important roles in the control of motivated behaviour, and one with considerable practical implications.


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