scholarly journals The Effects of Intraoperative Hypothermia on Postoperative Cognitive Function in the Rat Hippocampus and Its Possible Mechanisms

2022 ◽  
Vol 12 (1) ◽  
pp. 96
Author(s):  
Guangyan Xu ◽  
Tianjia Li ◽  
Yuguang Huang
Keyword(s):  
Working Memory ◽  
Synaptic Plasticity ◽  
Cognitive Function ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Hippocampal Neurons ◽  
Spatial Working Memory ◽  
Postoperative Cognitive Dysfunction ◽  
Spatial Learning And Memory ◽  
Intraoperative Hypothermia

Intraoperative hypothermia is a common complication during operations and is associated with several adverse events. Postoperative cognitive dysfunction (POCD) and its adverse consequences have drawn increasing attention in recent years. There are currently no relevant studies investigating the correlation between intraoperative hypothermia and POCD. The aim of this study was to assess the effects of intraoperative hypothermia on postoperative cognitive function in rats undergoing exploratory laparotomies and to investigate the possible related mechanisms. We used the Y-maze and Morris Water Maze (MWM) tests to assess the rats’ postoperative spatial working memory, spatial learning, and memory. The morphological changes in hippocampal neurons were examined by haematoxylin-eosin (HE) staining and hippocampal synaptic plasticity-related protein expression. Activity-regulated cytoskeletal-associated protein (Arc), cyclic adenosine monophosphate-response element-binding protein (CREB), S133-phosphorylated CREB (p-CREB [S133]), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor 1 (AMPAR1), and S831-phosphorylated AMPAR1 (p-AMPAR1 [S831]) were evaluated by Western blotting. Our results suggest a correlation between intraoperative hypothermia and POCD in rats and that intraoperative hypothermia may lead to POCD regarding impairments in spatial working memory, spatial learning, and memory. POCD induced by intraoperative hypothermia might be due to hippocampal neurons damage and decreased expression of synaptic plasticity-related proteins Arc, p-CREB (S133), and p-AMPAR1 (S831).

scholarly journals Treadmill Exercise Prevents Decline in Spatial Learning and Memory in 3×Tg-AD Mice through Enhancement of Structural Synaptic Plasticity of the Hippocampus and Prefrontal Cortex

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 244
Author(s):  
Lianwei Mu ◽  
Jiajia Cai ◽  
Boya Gu ◽  
Laikang Yu ◽  
Cui Li ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Synaptic Plasticity ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Treadmill Exercise ◽  
Spatial Working Memory ◽  
Spatial Learning And Memory ◽  
Pathological Feature ◽  
Dendritic Complexity

Alzheimer’s disease (AD) is characterized by deficits in learning and memory. A pathological feature of AD is the alterations in the number and size of synapses, axon length, dendritic complexity, and dendritic spine numbers in the hippocampus and prefrontal cortex. Treadmill exercise can enhance synaptic plasticity in mouse or rat models of stroke, ischemia, and dementia. The aim of this study was to examine the effects of treadmill exercise on learning and memory, and structural synaptic plasticity in 3×Tg-AD mice, a mouse model of AD. Here, we show that 12 weeks treadmill exercise beginning in three-month-old mice improves spatial working memory in six-month-old 3×Tg-AD mice, while non-exercise six-month-old 3×Tg-AD mice exhibited impaired spatial working memory. To investigate potential mechanisms for the treadmill exercise-induced improvement of spatial learning and memory, we examined structural synaptic plasticity in the hippocampus and prefrontal cortex of six-month-old 3×Tg-AD mice that had undergone 12 weeks of treadmill exercise. We found that treadmill exercise led to increases in synapse numbers, synaptic structural parameters, the expression of synaptophysin (Syn, a presynaptic marker), the axon length, dendritic complexity, and the number of dendritic spines in 3×Tg-AD mice and restored these parameters to similar levels of non-Tg control mice without treadmill exercise. In addition, treadmill exercise also improved these parameters in non-Tg control mice. Strengthening structural synaptic plasticity may represent a potential mechanism by which treadmill exercise prevents decline in spatial learning and memory and synapse loss in 3×Tg-AD mice.

scholarly journals GABAB receptor antagonist promotes hippocampal neurogenesis and facilitates cognitive function recovery following acute cerebral ischemia in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dan Song ◽  
Yaohua Chen ◽  
Cheng Chen ◽  
Lili Chen ◽  
Oumei Cheng
Keyword(s):  
Cognitive Function ◽  
Cerebral Ischemia ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Hippocampal Neurogenesis ◽  
Morris Water Maze Test ◽  
Spatial Learning And Memory ◽  
In Vitro Experiments ◽  
Adult Mice

Abstract Purpose and background Previous studies have suggested that promoting endogenous neurogenesis has great significance for the recovery of cognitive dysfunction caused by cerebral ischemia (CI). Pharmacological inhibition of GABAB receptor can enhance neurogenesis in adult healthy and depressed mice. In the study, we intended to investigate the effects of GABAB receptor antagonists on cognitive function and hippocampal neurogenesis in mice following CI. Methods Adult mice were subjected to bilateral common carotid artery occlusion (BCCAO) for 20 min to induce CI and treated with CGP52432 (antagonist of GABAB receptor, CGP, 10 mg/kg intraperitoneal injection) starting 24 h after CI. The Morris water maze test was performed to test spatial learning and memory at day 28. Immunofluorescence was applied to detect neurogenesis in the DG region at day 14 and 28. In in vitro experiments, cell proliferation was detected by CCK8 and immunofluorescence, and the expression of cAMP/CREB signaling pathway-related proteins was detected by ELISA assay and Western blot. Results CGP significantly improved spatial learning and memory disorders caused by CI, and it enhanced the proliferation of neural stem cells (NSCs), the number of immature neurons, and the differentiation from newborn cells to neurons. In vitro experiments further confirmed that CGP dose-dependently enhanced the cell viability of NSCs, and immunofluorescence staining showed that CGP promoted the proliferation of NSCs. In addition, treatment with CGP increased the expression of cAMP, PKA, and pCREB in cultured NSCs. Conclusion Inhibition of GABAB receptor can effectively promote hippocampal neurogenesis and improve spatial learning and memory in adult mice following CI.

scholarly journals Tripchlorolide May Improve Spatial Cognition Dysfunction and Synaptic Plasticity after Chronic Cerebral Hypoperfusion

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Zhao-Hui Yao ◽  
Xiao-li Yao ◽  
Shao-feng Zhang ◽  
Ji-chang Hu ◽  
Yong Zhang
Keyword(s):  
Cognitive Impairment ◽  
Synaptic Plasticity ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Long Term Potentiation ◽  
Chronic Cerebral Hypoperfusion ◽  
Synaptic Proteins ◽  
Cerebral Hypoperfusion ◽  
Spatial Learning And Memory ◽  
Pathophysiological Mechanism

Chronic cerebral hypoperfusion (CCH) is a common pathophysiological mechanism that underlies cognitive decline and degenerative processes in dementia and other neurodegenerative diseases. Low cerebral blood flow (CBF) during CCH leads to disturbances in the homeostasis of hemodynamics and energy metabolism, which in turn results in oxidative stress, astroglia overactivation, and synaptic protein downregulation. These events contribute to synaptic plasticity and cognitive dysfunction after CCH. Tripchlorolide (TRC) is an herbal compound with potent neuroprotective effects. The potential of TRC to improve CCH-induced cognitive impairment has not yet been determined. In the current study, we employed behavioral techniques, electrophysiology, Western blotting, immunofluorescence, and Golgi staining to investigate the effect of TRC on spatial learning and memory impairment and on synaptic plasticity changes in rats after CCH. Our findings showed that TRC could rescue CCH-induced spatial learning and memory dysfunction and improve long-term potentiation (LTP) disorders. We also found that TRC could prevent CCH-induced reductions in N-methyl-D-aspartic acid receptor 2B, synapsin I, and postsynaptic density protein 95 levels. Moreover, TRC upregulated cAMP-response element binding protein, which is an important transcription factor for synaptic proteins. TRC also prevented the reduction in dendritic spine density that is caused by CCH. However, sham rats treated with TRC did not show any improvement in cognition. Because CCH causes disturbances in brain energy homeostasis, TRC therapy may resolve this instability by correcting a variety of cognitive-related signaling pathways. However, for the normal brain, TRC treatment led to neither disturbance nor improvement in neural plasticity. Additionally, this treatment neither impaired nor further improved cognition. In conclusion, we found that TRC can improve spatial learning and memory, enhance synaptic plasticity, upregulate the expression of some synaptic proteins, and increase the density of dendritic spines. Our findings suggest that TRC may be beneficial in the treatment of cognitive impairment induced by CCH.

scholarly journals Focal Adhesion Kinase Regulates Neuronal Growth, Synaptic Plasticity and Hippocampus-Dependent Spatial Learning and Memory

Neurosignals ◽  
2011 ◽  
Vol 20 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Francisco J. Monje ◽  
Eun-Jung Kim ◽  
Daniela D. Pollak ◽  
Maureen Cabatic ◽  
Lin Li ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Focal Adhesion Kinase ◽  
Learning And Memory ◽  
Focal Adhesion ◽  
Spatial Learning ◽  
Spatial Learning And Memory ◽  
Neuronal Growth

scholarly journals Aged Brains Express Less Melanocortin Receptors, Which Correlates with Age-Related Decline of Cognitive Functions

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6266
Author(s):  
Yang Zhou ◽  
Monica K. Chawla ◽  
Jose L. Rios-Monterrosa ◽  
Lingzhi Wang ◽  
Marc A. Zempare ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Learning And Memory ◽  
Spatial Learning ◽  
Cognitive Functions ◽  
Drug Targets ◽  
Brain Regions ◽  
Cognitive Status ◽  
Melanocortin Receptors ◽  
Spatial Learning And Memory ◽  
Age Related

Brain G-protein coupled receptors have been hypothesized to be potential targets for maintaining or restoring cognitive function in normal aged individuals or in patients with neurodegenerative disease. A number of recent reports suggest that activation of melanocortin receptors (MCRs) in the brain can significantly improve cognitive functions of normal rodents and of different rodent models of the Alzheimer’s disease. However, the potential impact of normative aging on the expression of MCRs and their potential roles for modulating cognitive function remains to be elucidated. In the present study, we first investigated the expression of these receptors in six different brain regions of young (6 months) and aged (23 months) rats following assessment of their cognitive status. Correlation analysis was further performed to reveal potential contributions of MCR subtypes to spatial learning and memory. Our results revealed statistically significant correlations between the expression of several MCR subtypes in the frontal cortex/hypothalamus and the hippocampus regions and the rats’ performance in spatial learning and memory only in the aged rats. These findings support the hypothesis that aging has a direct impact on the expression and function of MCRs, establishing MCRs as potential drug targets to alleviate aging-induced decline of cognitive function.

scholarly journals Wnt5a is essential for hippocampal dendritic maintenance and spatial learning and memory in adult mice

2017 ◽  
Vol 114 (4) ◽  
pp. E619-E628 ◽  
Author(s):  
Chih-Ming Chen ◽  
Lauren L. Orefice ◽  
Shu-Ling Chiu ◽  
Tara A. LeGates ◽  
Samer Hattar ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Spatial Learning ◽  
Hippocampal Neurons ◽  
Pyramidal Neurons ◽  
Neuronal Morphology ◽  
Adult Brain ◽  
Receptor Expression ◽  
Spatial Learning And Memory ◽  
Brain Functions ◽  
Wnt5a Expression

Stability of neuronal connectivity is critical for brain functions, and morphological perturbations are associated with neurodegenerative disorders. However, how neuronal morphology is maintained in the adult brain remains poorly understood. Here, we identify Wnt5a, a member of the Wnt family of secreted morphogens, as an essential factor in maintaining dendritic architecture in the adult hippocampus and for related cognitive functions in mice. Wnt5a expression in hippocampal neurons begins postnatally, and its deletion attenuated CaMKII and Rac1 activity, reduced GluN1 glutamate receptor expression, and impaired synaptic plasticity and spatial learning and memory in 3-mo-old mice. With increased age, Wnt5a loss caused progressive attrition of dendrite arbors and spines in Cornu Ammonis (CA)1 pyramidal neurons and exacerbated behavioral defects. Wnt5a functions cell-autonomously to maintain CA1 dendrites, and exogenous Wnt5a expression corrected structural anomalies even at late-adult stages. These findings reveal a maintenance factor in the adult brain, and highlight a trophic pathway that can be targeted to ameliorate dendrite loss in pathological conditions.

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