PKMzeta involvement in cocaine sensitization

描述（由申请方提供）：可卡因致敏是由随后的可卡因激发诱导的运动兴奋剂作用的进行性和持久增强。这项工作的目标是阐明，如果持久的活动PKM？在VTA和NAc维持可卡因致敏的发展和表达。具体目的有三：1）评价PKM的效果;抑制可卡因行为敏化的发展和表达。我们将使用行为敏化范式与内VTA和内NAc微量输注ZIP（PKM？选择性抑制剂）在敏化的不同阶段 确定PKM的过程？在行为敏感化的发展和表达中的作用。假设ZIP在腹侧被盖区和腹侧被盖区的给药将阻断可卡因致敏作用的发生和表达。抑制可卡因致敏后VTA DA和NAc中棘神经元AMPA电流和AMPA/NMDA比值。使用VTA DA和NAc中棘神经元的全细胞记录，我们将测量重复暴露于可卡因的大鼠的AMPA介导的EPSC和AMPA/NMDA比率。ZIP将被用来评估是否PKM？是维持可卡因诱导的增强作用所必需的。我们假设ZIP将诱导AMPA电流的减少，因此，将减少可卡因致敏动物的AMPA/NMDA比率至基础水平。3)评估PKM？抑制剂对成瘾相关的可塑性发挥作用。使用蛋白质印迹分析，我们将测量PKM和AMPA受体亚单位水平的VTA和NAc在发展和可卡因致敏的表达。第二，我们将使用显微注射的合成肽Tat-GluR 23 y和整流指数曲线在全细胞补丁记录检查的贡献GluR 2依赖和GluR 2缺乏AMPA受体在维持PKM？可卡因致敏作用。假设可卡因致敏涉及PKM的增加？水平，其通过抑制GluR 2依赖性AMPA受体从突触后位点的移除而起作用。这项研究将提供一个更好的基本了解药物诱导的可塑性在中枢神经系统，并可能提出治疗药理学干预的可能途径。

DESCRIPTION (provided by applicant): Cocaine sensitization is a progressive and long-lasting enhancement of the motor stimulant effect induced by a subsequent cocaine challenge. The goal of this work is to elucidate if the persistent activity of PKM? in the VTA and NAc sustains the development and expression of cocaine sensitization. There are three specific aims: 1) to evaluate the effect of PKM? inhibition in the development and expression of cocaine behavioral sensitization. We will use a behavioral sensitization paradigm with intra VTA and intra NAc microinfusions of ZIP (PKM? selective inhibitor) at different stages of the sensitization process to determine PKM? 's role in the development and expression of behavioral sensitization. The hypothesize is that ZIP administration in the VTA and NAc will block the development and expression of cocaine sensitization 2) To determine the role of PKM? inhibition on AMPA currents and AMPA/NMDA ratios in VTA DA and NAc medium spiny neurons after cocaine sensitization. Using whole cell recordings from VTA DA and NAc medium spiny neurons, we will measure AMPA mediated EPSCs and AMPA/NMDA ratios from rats repeatedly exposed to cocaine. ZIP will be used to assess whether PKM? is necessary for the maintenance of the cocaine-induced potentiation. We hypothesize that ZIP will induce a decrease in AMPA currents and therefore, will diminish AMPA/NMDA ratios to basal levels in cocaine sensitized animals. 3) To assess the cellular substrate by which the PKM? inhibitor exerts its effects on addiction related plasticity. Using western blot analysis we will measure PKM¿ and AMPA receptor subunit levels in the VTA and NAc during development and expression of cocaine sensitization. Second, we will use microinjections of the synthetic peptide Tat-GluR23y and rectification index curves in whole cell patch recordings to examine the contribution of GluR2-dependent and GluR2-lacking AMPA receptors in maintaining PKM? effects in cocaine sensitization. The hypothesis is that cocaine sensitization involves an increase in PKM? levels which is acting by inhibiting GluR2-dependent AMPA receptor removal from postsynaptic sites. This research will provide a better fundamental understanding of drug-induced plasticities in the CNS and might present possible avenues for therapeutic pharmacological interventions.