Transgenerational inheritance of a Cocaine resistance phenotype

这项研究的重点是父亲服用可卡因对生理和行为的影响。 后代人(即后代和格兰多夫后代)。人类流行病学数据表明 可卡因成瘾通常伴随着认知能力下降，包括间歇性记忆障碍。我们的 工作假说是父亲的可卡因暴露引起学习和突触可塑性损害 通过降低海马区D-丝氨酸水平/NMDA受体信号传递雄性后代和颗粒后代。在……里面 具体目标1，学习和记忆以及长时程增强(LTP)，这是一种普遍接受的 生理学习的相关性，将在自我注射可卡因的后代中进行评估。 基于对象的记忆测试的初步发现表明，男性而不是女性的后代和 暴露于可卡因的父鼠的颗粒后代损害了海马区依赖的物体位置记忆。 父亲的可卡因暴露也损害了雄性后代的海马LTP。在具体目标2中，我们将评估 假设可卡因成年后代的这些学习和突触可塑性缺陷- 经验丰富的雄性是由于背侧海马区D-丝氨酸/NMDA受体信号减弱，这是 与空间学习和突触可塑性密切相关。初步数据显示，D-丝氨酸水平为 在可卡因繁殖的雄性大鼠的背侧海马区。D-氨基酸氧化酶(DAAO) 催化D-丝氨酸的氧化脱氨反应。初步数据表明，daao1的mRNA水平是 在可卡因雄性大鼠的背侧海马区增加。研究潜在的表观遗传机制 在daao1mRNA增加的基础上，与daao1相关的组蛋白翻译后修饰将是 在F1和F2代进行检测。最后，将给予D-丝氨酸、D-环丝氨酸或DAAO抑制剂 进入背侧海马区或可卡因祖系大鼠的海马片，我们 预测将挽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 通过评估有可卡因经验的雄性和雄性精子中miRNA的变化来实现世代之间的转移 他们的后代。初步数据表明，可卡因自身给药显著改变了四个miRNAs(miR- 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服可卡因和碘化可卡因， 它不会穿过血脑屏障。我们还将评估可卡因引起的变化的持续时间 在可卡因自身给药后1天或90天通过评估miRNAs来检测精子。总而言之，这些 实验将确定可卡因经历过的雄性后代的海马体功能的变化 导致这些动物的学习缺陷。我们还将检查可卡因引起的精子变化。 这可能会在几代人之间传递信息。总之，我们定义了一个可遗传的可卡因诱导的新模型 学习缺陷。这些结果对可卡因成瘾者的后代有着明确而重要的影响。

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.