Behavioural brain research
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The reuniens nucleus (RE) is the largest nucleus of the midline thalamic nuclei (MLN). RE has strongly connections with the amygdala and hippocampus, the structures that are involved in the learning and memory processes. In our previous report we have shown the role of RE in the spatial learning and memory using Morris water maze (MWM) task. ⋯ Moreover, inactivation of RE only 5 min after training impaired consolidation but not after 90 or 360 min. Also, inactivation of the RE, 5 min before the retrieval test impaired memory retrieval in PA task. In conclusion, it seems that RE is involved in memory processes in rats.
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The aim of this study was to test the hypothesis that nuclear factor-kappa B (NF-κB) is involved in TRPV4-NO pathway in thermal hyperalgesia following chronic compression of the dorsal root ganglion (DRG) (the procedure hereafter termed CCD) in rat. Intrathecal administration of two NF-κB inhibitors, pyrrolidine dithiocarbamate (PDTC; 10(-1) to 10(-2)M) and BAY (100-50 μM), both induced significantly dose-dependent increase in the paw withdrawal latency (PWL) and decrease in nitric oxide (NO) content in DRG when compared with control rats. ⋯ In addition, Western blot analysis indicated that CCD rats exhibited nuclear NF-κB protein expression and low levels of cytoplasmic inhibitory-kappa B (I-κB) expression; the increase in NF-κB expression and decrease in I-κB expression were reversed after intrathecal injection of PDTC. In conclusion, our data suggested that NF-κB could be involved in TRPV4-NO pathway in CCD-induced thermal hyperalgesia.
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Depression has recently become a serious problem in society worldwide. However, we lack appropriate therapeutic tools, since the causes of depression remain unclear. Degeneration of neuronal cells and a decrease in neurogenesis have been suggested recently as two of the factors responsible for depression-like behavior. ⋯ We next investigated the extent of cell proliferation in the hippocampus as 5-bromo-2'-deoxy-uridine (BrdU) uptake into hippocampal cells. Repeated FST significantly reduced the number of BrdU-positive cells in the hippocampal dentate gyrus, while this deficit was prevented by repeated Leu-Ile treatment. These results suggest that Leu-Ile has an antidepressant-like effect, at least in part by supporting cell proliferation through the BDNF signaling pathway.
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In this study, we decided to use low doses of memantine pretreatment to examine the roles of the immune function in cocaine-supported conditioning. Cocaine-induced conditioned place preference (CPP) was used to assess the hedonic value and/or reinforcing efficacy of cocaine and cocaine-supported conditioning. Systemic pretreatment with memantine (20, 2.0, 0.2, and 0.02 mg/kg/injection) 30 min before each cocaine and saline conditioning trial abolished the acquisition of cocaine-induced CPP in mice. ⋯ Finally, intra-mPFC infusion of recombinant IL-6, but not thalidomide, reversed memantine (0.02 mg/kg/injection × 6)-decreased cocaine-induced CPP. These results, taken together, suggest that cocaine conditioning-enhanced IL-6 in mPFC may be, in part, involved in the acquisition of cocaine-induced CPP. Moreover, an extremely low dose of memantine may decrease the acquisition of cocaine-induced CPP by reversing cocaine conditioning-increased IL-6 levels in mPFC.
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Memory impairment induced by streptozotocin in rats is a consequence of changes in CNS that are secondary to chronic hyperglycemia, impaired oxidative stress, cholinergic dysfunction, and changes in glucagon-like peptide (GLP). Treatment with antihyperglycemics, antioxidants, and cholinergic agonists are reported to produce beneficial effect in this model. Berberine, an isoquinoline alkaloid is reported to exhibit anti-diabetic and antioxidant effect, acetylcholinesterase (AChE) inhibitor, and increases GLP release. ⋯ In another set of experiment, berberine (100mg/kg) treatment during training trials also improved learning and memory, lowered hyperglycemia, oxidative stress, and ChE activity. Chronic treatment (30 days) with vitamin C or metformin, and donepezil during training trials also improved diabetes-induced memory impairment and reduced oxidative stress and/or choline esterase activity. In conclusion, the present study demonstrates treatment with berberine prevents the changes in oxidative stress and ChE activity, and consequently memory impairment in diabetic rats.