Transgenerational inheritance of a Cocaine resistance phenotype

这项研究计划的重点是父亲服用可卡因对生理和行为的影响 后代（即子孙）。人类流行病学数据表明， 可卡因成瘾往往伴随着认知能力下降，包括情节记忆障碍。我们 工作假设是，父亲的可卡因暴露elevated学习和突触可塑性损伤， 通过降低海马体中D-丝氨酸水平/NMDA受体信号传导，在 具体目标1，学习和记忆以及长时程增强（LTP），一种普遍接受的 生理学习相关性，将在自我施用可卡因的公鹿的后代中进行评估。 基于对象的记忆测试的初步结果表明，男性，而不是女性，后代和 暴露于可卡因的公马的后代具有受损的海马依赖的对象位置记忆。 父亲的可卡因暴露也损害海马LTP在男性后代。在具体目标2中，我们将评估 假设可卡因的成年后代的这些学习和突触可塑性缺陷- 经验丰富的公畜是由于减少背海马D-丝氨酸/NMDA受体信号，这是 与空间学习和突触可塑性密切相关。初步数据表明，D-丝氨酸水平 减少在背部海马可卡因sireded雄性大鼠。D-氨基酸氧化酶（DAAO） 催化D-丝氨酸的氧化脱氨。初步数据表明，daao 1 mRNA水平是 可卡因雄性大鼠的背海马中增加。研究潜在的表观遗传机制 在daao 1 mRNA增加的基础上，与daao 1相关的组蛋白翻译后修饰将是 在F1和F2代进行了检测。最后，将施用D-丝氨酸、D-环丝氨酸或DAAO抑制剂。 到背侧海马或到可卡因后代或可卡因后代大鼠的海马切片上， 预测将拯救空间学习和可塑性缺陷。在具体目标3中，我们将评估信息是如何 通过评估可卡因经验的父系精子中miRNA的变化， 他们的后代。初步数据表明，可卡因自我给药显著改变了四种miRNA（miR-125）。 1-3p、miR-206-3p、miR-1b、miR-362-3p）。为了确定是否需要CNS， 可卡因对精子miRNAs的影响我们将比较自我施用的可卡因与偶联的可卡因甲碘化物， 它不能穿过血脑屏障。我们还将评估可卡因引起的变化的持续时间， 通过评估可卡因自我给药后1天或90天的miRNAs来评估精子。总的来说，这些 实验将确定可卡因经验的公牛后代海马功能的变化， 导致了这些动物的学习缺陷。我们还将研究可卡因引起的精子变化 可能携带着世代之间的信息。总的来说，我们定义了一种新的遗传性可卡因诱导的模型， 学习缺陷这些结果对可卡因成瘾者的后代具有明确而重要的意义。

The focus of this research program is the influence of paternal cocaine taking on the physiology and behavior of subsequent generations (i.e. offspring and grandoffspring). Human epidemiological data indicates that cocaine addiction is often accompanied by cognitive decline including episodic memory impairments. Our working hypothesis is that paternal cocaine exposure elicits learning and synaptic plasticity impairments in male offspring and grandoffspring by reducing D-serine levels/NMDA receptor signaling in the hippocampus. In Specific Aim 1, learning and memory as well as long term potentiation (LTP), a generally accepted physiological learning correlate, will be assessed in the offspring of sires that self-administered cocaine. Preliminary findings from object-based memory assays indicate that male, but not female, offspring and grandoffspring of cocaine-exposed sires have impaired hippocampus-dependent object location memory. Paternal cocaine exposure also impairs hippocampal LTP in male offspring. In Specific Aim 2 we will evaluate the hypothesis that these learning and synaptic plasticity deficits in the adult descendants of cocaine- experienced sires are due to decreased dorsal hippocampal D-serine/NMDA receptor signaling, which are critically involved in spatial learning and synaptic plasticity. Preliminary data indicate that D-serine levels are decreased in the dorsal hippocampus of cocaine-sired male rats. The enzyme D-amino acid oxidase (DAAO) catalyzes the oxidative deamination of D-serine. Preliminary data indicate that daao1 mRNA levels are increased in the dorsal hippocampus of cocaine-sired male rats. To examine potential epigenetic mechanisms underlying the increase in daao1 mRNA, histone posttranslational modifications associated with daao1 will be examined in F1 and F2 generations. Finally, D-serine, D-cycloserine or a DAAO inhibitor will be administered into the dorsal hippocampus or onto hippocampal slices of cocaine-sired or cocaine-grandsired rats, which we predict will rescue spatial learning and plasticity deficits. In Specific Aim 3 we will evaluate how information is transferred between generations by assessing miRNA changes in the sperm of cocaine-experienced sires and their offspring. Preliminary data indicate that cocaine self-administration significantly altered four miRNAs (miR- 1-3p, miR-206-3p, miR-1b, miR-362-3p) in sire sperm. In order to determine if the CNS is required for the effect of cocaine on sperm miRNAs we will compare self-administered cocaine to yoked cocaine methiodide, which does not cross the blood-brain barrier. We also will assess the duration of cocaine-induced changes in sperm by evaluating miRNAs 1 or 90 days following cocaine self-administration. Collectively, these experiments will determine changes in hippocampal function in the descendants of cocaine-experienced sires that contribute to learning deficits in these animals. We also will examine cocaine-induced changes in sperm that may carry information between generations. Overall, we define a novel model of heritable cocaine-induced learning deficits. These results have clear and significant implications for the descendants of cocaine addicts.