scholarly journals Embelin Improves the Spatial Memory and Hippocampal Long-Term Potentiation in a Rat Model of Chronic Cerebral Hypoperfusion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Saatheeyavaane Bhuvanendran ◽  
Siti Najmi Syuhadaa Bakar ◽  
Yatinesh Kumari ◽  
Iekhsan Othman ◽  
Mohd. Farooq Shaikh ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Spatial Memory ◽  
Rat Model ◽  
Long Term Potentiation ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Mrna Levels ◽  
Post Surgery ◽  
Term Potentiation

Abstract Alzheimer’s disease (AD) is the second most occurring neurological disorder after stroke and is associated with cerebral hypoperfusion, possibly contributing to cognitive impairment. In the present study, neuroprotective and anti-AD effects of embelin were evaluated in chronic cerebral hypoperfusion (CCH) rat model using permanent bilateral common carotid artery occlusion (BCCAO) method. Rats were administered with embelin at doses of 0.3, 0.6 or 1.2 mg/kg (i.p) on day 14 post-surgery and tested in Morris water maze (MWM) followed by electrophysiological recordings to access cognitive abilities and synaptic plasticity. The hippocampal brain regions were extracted for gene expression and neurotransmitters analysis. Treatment with embelin at the doses of 0.3 and 0.6 mg/kg significantly reversed the spatial memory impairment induced by CCH in rats. Embelin treatment has significantly protected synaptic plasticity impairment as assessed by hippocampal long-term potentiation (LTP) test. The mechanism of this study demonstrated that embelin treatment alleviated the decreased expression of BDNF, CREB1, APP, Mapt, SOD1 and NFκB mRNA levels caused by CCH rats. Furthermore, treatment with embelin demonstrated neuromodulatory activity by its ability to restore hippocampal neurotransmitters. Overall these data suggest that embelin improve memory and synaptic plasticity impairment in CCH rats and can be a potential drug candidate for neurodegenerative disease-related cognitive disorders.

scholarly journals Alpha-synuclein is involved in manganese-induced spatial memory and synaptic plasticity impairments via TrkB/Akt/Fyn-mediated phosphorylation of NMDA receptors

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Zhuo Ma ◽  
Kuan Liu ◽  
Xin-Ru Li ◽  
Can Wang ◽  
Chang Liu ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Spatial Memory ◽  
Long Term Potentiation ◽  
Alpha Synuclein ◽  
Ht22 Cells ◽  
Protein Levels ◽  
Trkb Receptors ◽  
Term Potentiation

Abstract Manganese (Mn) overexposure produces long-term cognitive deficits and reduces brain-derived neurotrophic factor (BDNF) in the hippocampus. However, it remains elusive whether Mn-dependent enhanced alpha-synuclein (α-Syn) expression, suggesting a multifaceted mode of neuronal toxicities, accounts for interference with BDNF/TrkB signaling. In this study, we used C57BL/6J WT and α-Syn knockout (KO) mice to establish a model of manganism and found that Mn-induced impairments in spatial memory and synaptic plasticity were related to the α-Syn protein. In addition, consistent with the long-term potentiation (LTP) impairments that were observed, α-Syn KO relieved Mn-induced degradation of PSD95, phosphorylated CaMKIIα, and downregulated SynGAP protein levels. We transfected HT22 cells with lentivirus (LV)-α-Syn shRNA, followed by BDNF and Mn stimulation. In vitro experiments indicated that α-Syn selectively interacted with TrkB receptors and inhibited BDNF/TrkB signaling, leading to phosphorylation and downregulation of GluN2B. The binding of α-Syn to TrkB and Fyn-mediated phosphorylation of GluN2B were negatively regulated by BDNF. Together, these findings indicate that Mn-dependent enhanced α-Syn expression contributes to further exacerbate BDNF protein-level reduction and to inhibit TrkB/Akt/Fyn signaling, thereby disturbing Fyn-mediated phosphorylation of the NMDA receptor GluN2B subunit at tyrosine. In KO α-Syn mice treated with Mn, spatial memory and LTP impairments were less pronounced than in WT mice. However, the same robust neuronal death was observed as a result of Mn-induced neurotoxicity.

scholarly journals Citalopram Ameliorates Impairments in Spatial Memory and Synaptic Plasticity in Female 3xTgAD Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Zhang Wei ◽  
Guo Junhong ◽  
Niu Xiaoyuan ◽  
Wang Jie ◽  
Wang Zhaojun ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Spatial Memory ◽  
Antidepressant Drug ◽  
Amyloid Plaques ◽  
Long Term Potentiation ◽  
Memory Deficit ◽  
Behavioral Performance ◽  
Promising Strategy ◽  
Term Potentiation

Alzheimer’s disease (AD) is the primary cause of dementia. There is no effective treatment. Amyloid-β peptide (Aβ) plays an important role in the pathogenesis and thus strategies suppressing Aβ production and accumulation seem promising. Citalopram is an antidepressant drug and can decrease Aβ production and amyloid plaques in transgenic mice of AD and humans. Whether citalopram can ameliorate memory deficit was not known yet. We tested the effects of citalopram on behavioral performance and synaptic plasticity in female 3xTgAD mice, a well-characterized model of AD. Mice were treated with citalopram or water from 5 months of age for 3 months. Citalopram treatment at approximately 10 mg/kg/day significantly improved spatial memory in the Morris water maze (MWM) test, while not affecting anxiety-like and depression-like behavior in 3xTgAD mice. Further, hippocampal long-term potentiation (LTP) impairment in 3xTgAD mice was reversed by citalopram treatment. Citalopram treatment also significantly decreased the levels of insoluble Aβ40 in hippocampal and cortical tissues in 3xTgAD mice, accompanied with a reduced amyloid precursor protein (APP). Together, citalopram treatment may be a promising strategy for AD and further clinical trials should be conducted to verify the effect of citalopram on cognition in patients with AD or mild cognitive impairment.

Long-term potentiation saturation in chronic cerebral hypoperfusion

1998 ◽  
Vol 5 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Lali H.S Sekhon ◽  
Ian Spence ◽  
Michael K Morgan ◽  
Neville C Weber
Keyword(s):  
Long Term Potentiation ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Term Potentiation

Chronic Cerebral Hypoperfusion Inhibits Calcium-Induced Long-term Potentiation in Rats

Stroke ◽  
1997 ◽  
Vol 28 (5) ◽  
pp. 1043-1048 ◽  
Author(s):  
Lali H. S. Sekhon ◽  
Ian Spence ◽  
Michael K. Morgan ◽  
Neville C. Weber
Keyword(s):  
Long Term Potentiation ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Term Potentiation

Cholinergic modulation of hippocampal long-term potentiation in chronic cerebral hypoperfused rats

2018 ◽  
Vol 1 (1) ◽  
pp. 42-57 ◽  
Author(s):  
Nor Fasihah Azam ◽  
Ryan Andrew Stanyard ◽  
Noorul Hamizah Mat ◽  
Zurina Hassan
Keyword(s):  
Synaptic Transmission ◽  
Rat Model ◽  
Neuronal Loss ◽  
Long Term Potentiation ◽  
Cerebral Hypoperfusion ◽  
Vessel Occlusion ◽  
Term Potentiation ◽  
Significant Impairment

Vascular dementia (VaD) is one of the most common types of dementia in Alzheimer’s disease (AD). Two-vessel occlusion (2VO), also known as permanent bilateral occlusion of the common carotid arteries, induces chronic cerebral hypoperfusion (CCH) in rats, resulting in neuronal loss and inflammation (particularly in the cortex and hippocampus).  The 2VO rat model has been widely used to represent VaD conditions similar to those seen in humans. Synaptic plasticity or long-term potentiation (LTP) is one of the most important neurochemical foundations in learning and memory, deficits of which occur as a result of VaD. The aim of this study is to evaluate the role of cholinergic transmission in LTP impairment of CCH rat model. There is a significant impairment of LTP following the induction of 2VO surgery (p < .05). Treatment with oxotremorine and tacrine cause significant enhancement of LTP and potentiation levels (p < .05). There are also significant effects of paired-pulse facilitations when treated with cholinergic agonists and baseline synaptic transmission with increasing stimulation intensity (p < .0001). AChE activity was only found to increase significantly in the hippocampal region (p < .05). The role of cholinergic neurotransmission has been clearly demonstrated in LTP impairment of the CCH rat model. Augmentation of synaptic transmission was clearly observed in this model via changes of basal synaptic transmission and neurotransmitter release presynaptically.

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