Glutamatergic and central cholinergic dysfunction in the CA1, CA2 and CA3 fields on spatial learning and memory in chronic cerebral ischemia—Induced vascular dementia of rats

2016 ◽  
Vol 620 ◽  
pp. 169-176 ◽  
Author(s):  
Yanjing Cao ◽  
Zengmei Gou ◽  
Yifeng Du ◽  
Yongjun Fan ◽  
Lizhen Liang ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dan Song ◽  
Yaohua Chen ◽  
Cheng Chen ◽  
Lili Chen ◽  
Oumei Cheng

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.


2005 ◽  
Vol 25 (12) ◽  
pp. 1586-1595 ◽  
Author(s):  
Olof Bendel ◽  
Tjerk Bueters ◽  
Mia von Euler ◽  
Sven Ove Ögren ◽  
Johan Sandin ◽  
...  

The pyramidal neurons of the hippocampal CA1 region are essential for cognitive functions such as spatial learning and memory, and are selectively destroyed after cerebral ischemia. To analyze whether degenerated CA1 neurons are replaced by new neurons and whether such regeneration is associated with amelioration in learning and memory deficits, we have used a rat global ischemia model that provides an almost complete disappearance (to approximately 3% of control) of CA1 neurons associated with a robust impairment in spatial learning and memory at two weeks after ischemia. We found that transient cerebral ischemia can evoke a massive formation of new neurons in the CA1 region, reaching approximately 40% of the original number of neurons at 90 days after ischemia (DAI). Co-localization of the mature neuronal marker neuronal nuclei with 5-bromo-2'-deoxyuridine in CA1 confirmed that neurogenesis indeed had occurred after the ischemic insult. Furthermore, we found increased numbers of cells expressing the immature neuron marker polysialic acid neuronal cell adhesion molecule in the adjacent lateral periventricular region, suggesting that the newly formed neurons derive from this region. The reappearance of CA1 neurons was associated with a recovery of ischemia-induced impairments in spatial learning and memory at 90 DAI, suggesting that the newly formed CA1 neurons restore hippocampal CA1 function. In conclusion, these results show that the brain has an endogenous capacity to form new nerve cells after injury, which correlates with a restoration of cognitive functions of the brain.


2013 ◽  
Vol 41 (06) ◽  
pp. 1329-1341 ◽  
Author(s):  
Bo Yin ◽  
Hui Liang ◽  
Yigang Chen ◽  
Ketan Chu ◽  
Li Huang ◽  
...  

Extracts of Ginkgo biloba have been used in traditional medicines for centuries, and have potential for clinical applications in cerebral ischemia/reperfusion injury. However, standardized extracts have proven protective only as pre-treatments, and the major mechanisms of action remain unclear. We explored the potential of the novel extract EGB1212, which meets the United States Pharmacopeia (USP) 31 standardization criteria for pharmaceutical use, as a post-treatment after global cerebral ischemia/reperfusion (GCI/R) injury in a rat model. The pre-treated group was administered EGB1212 for 7 d prior to common carotid artery occlusion (i.e., ischemia, for 20 min). Post-treated rats received the same but starting 2 h after ischemia and continuing for 7 d. Seven days after GCI/R, brains of each group were processed for H&E staining of hippocampal CA1 neurons. Remaining rats underwent the Morris water maze and Y-maze tests of spatial learning and memory, beginning eight days after reperfusion. To assess hippocampal autophagy, light chain (LC)-3-I/LC3-II and Akt/pAkt were determined via a Western blot of rat hippocampi harvested 12, 24, or 72 h after reperfusion. EGB1212 pre- and post-treatments both improved neuronal survival and spatial learning and memory functions. Pre-treatment effectively reduced LC3-II levels and post-treatment resulted in significantly elevated pAkt levels. We conclude that EGB1212 exerted significant neuroprotection in GCI/R in both preventative and post-treatment settings. This extract shows great potential for clinical applications.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Chun-Ying Li ◽  
Lei Zhang ◽  
Jing Li ◽  
Chun-Li Qi ◽  
Dong-Ying Li ◽  
...  

The hippocampus is a key structure for encoding and processing memory and for spatial orientation, which are among the cognitive functions most sensitive to cerebral ischemia, hypoxia, and vascular dementia (VD). Since hippocampal formation is one of the principle forebrain targets for arginine-vasopressin (AVP) innervations arising in the hypothalamic paraventricular nucleus (PVN), we explored the contributions of AVP to VD pathogenesis. To this end, we randomly assigned pathogen-free, male Wistar rats to one of seven groups in a VD model and tested AVP treatment effects on spatial learning and memory using the Morris water maze. We also measured the superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration in brain samples and monitored the expression of AVP-positive neurons in the hippocampus by immunohistochemistry. The VD model with repeated cerebral ischemia-reperfusion injury evoked impairment of cognitive function and reduced cerebral concentrations of the antioxidation markers. Lesioning the rat PVN showed a similar effect on learning and memory and reduced antioxidation markers in the brain tissue. However, AVP injection into the PVN improved cognitive performance in VD rats, while enhancing/rectifying the changes in antioxidation markers. We conclude that our VD model may decrease AVP secretion in the PVN and subsequently reduce antioxidant capacity in the hippocampus, leading to impaired cognitive function.


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