Neurochemical research
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Neurochemical research · Jan 2013
Regulation of ERα protein expression by 17β-estradiol in cultured neurons of hypothalamic ventromedial nucleus.
The activation of the subtype α of estrogen receptors (ERα) in the hypothalamic ventromedial nucleus (VMNvl) is required to stimulate female sexual receptivity. Moreover, the hormone was found to govern the expression of the receptor. Its removal due to ovariectomy and subsequent substitution suggest that the hormone down-regulates the expression of ERα. ⋯ The particular contribution of the receptors is dependent on their level of expression and the hormonal context. In neurons expressing high quantity of ERα, ERβ attenuates the overall expression of the receptor, whereas in cells containing mostly ERβ it contributes to the up-regulation of ERα synthesis. Simultaneous activation of ERs and PRs reverses the influences of the receptors due to inter-inhibition of their transcriptional activities.
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Neurochemical research · Jan 2013
Hippocampal glutamate level and glutamate aspartate transporter (GLAST) are up-regulated in senior rat associated with isoflurane-induced spatial learning/memory impairment.
Postoperative cognitive decline is a clinical concern especially for senior patients. It is generally recognized that glutamatergic system plays a crucial role in the physiopathologic process of neurocognitive deterioration. However, alterations of glutamatergic system in prolonged isoflurane-induced learning/memory decline are still unclear. ⋯ The learning/memory-impaired subgroup displayed a significantly higher GLAST level than the other three subgroups (p = 0.026, 0.02 and 0.032 respectively). The expression levels of GLT-1, NMDAR1, NMDAR2A/B and AMPAR of every subgroup were comparable. We found a continuous raised hippocampal glutamate and an up-regulation of GLAST rather than GLT-1, NMDAR1, NMDAR2A/B, AMPAR or tau in hippocampus of aged rats associated with isoflurane-induced learning/memory impairment.