Brain research bulletin
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Brain research bulletin · May 2015
CB1 receptors modulate affective behaviour induced by neuropathic pain.
Patients suffering from chronic pain are often diagnosed with a psychiatric condition, in particular generalized anxiety and major depression. The underlying pathomechanisms contributing to this comorbidity, however, are not entirely clear. In this manuscript we have focussed on the potential role of the cannabinoid receptor CB1, because it is known to modulate neuronal circuits contributing to chronic pain states and affective behaviours. ⋯ Our results show that the development of mechanical hypersensitivity was similar in CB1 deficient mice and wild type controls. However, CB1 knockouts showed much more pronounced behavioural manifestations of anxiety-related behaviours in the light-dark and zero-maze tests, sucrose anhedonia, and disturbed home-cage activity. These results indicate that the endocannabinoid system affects chronic pain-induced mood changes through CB1 receptors.
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Brain research bulletin · May 2015
ReviewTissue hypoxia during ischemic stroke: adaptive clues from hypoxia-tolerant animal models.
The treatment and prevention of hypoxic/ischemic brain injury in stroke patients remain a severe and global medical issue. Numerous clinical studies have resulted in a failure to develop chemical neuroprotection for acute, ischemic stroke. Over 150 estimated clinical trials of ischemic stroke treatments have been done, and more than 200 drugs and combinations of drugs for ischemic and hemorrhagic strokes have been developed. ⋯ This issue is of clinical significance to stroke patients. We describe specific physiological and molecular adaptations employed by different animals' models of hypoxia tolerance in aquatic and terrestrial environments. We highlight how these adaptations might provide potential clues on strategies to adapt for the clinical management of tissue hypoxia during conditions such as stroke where oxygen demand fails to match the supply.
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Brain research bulletin · May 2015
Hippocampal BDNF signaling restored with chronic asiaticoside treatment in depression-like mice.
Brain-derived neurotrophic factor (BDNF) plays a key role in the regulation of depression in the brain. Recently, increasing studies have focused on the antidepressant-like mechanism of BDNF and its downstream signaling pathway. A previous study has shown that asiaticoside produced an antidepressant-like action in the mouse tail suspension test and forced swimming test. ⋯ However, K252a, an inhibitor of BDNF receptor tropomyosin-related kinase receptor B (TrkB), completely abolished the antidepressant-like effect of asiaticoside. Moreover, the expression of hippocampal BDNF, PSD-95 and synapsin I that had increased with asiaticoside also declined with K252a pretreatment. In conclusion, our study implies that it is possible that asiaticoside exerts its antidepressant-like action by activating BDNF signaling in the hippocampus.
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Brain research bulletin · May 2015
Prophylactic lithium alleviates splenectomy-induced cognitive dysfunction possibly by inhibiting hippocampal TLR4 activation in aged rats.
Though the pathogenesis of postoperative cognitive dysfunction (POCD) remains unclear, evidence is accumulating for a pivotal role of neuroinflammation in the disease process. Advanced age and severe surgical trauma are two main risk factors for POCD. Lithium, a neuroprotective agent, can alleviate peripheral surgery-induced memory impairment in aged rats. ⋯ Then, we also found that splenectomy merely increased hippocampal TLR2 and TLR4 mRNA levels in aged rats. At last, we confirmed that prophylactic lithium reduced the increased levels of hippocampal TLR4/NF-κB induced by splenectomy. Taken together, these results demonstrate that TLR4 signaling inactivation may contribute to the protective effects of prophylactic lithium on the occurrence of POCD by inhibiting systemic inflammation and especially neuroinflammation.