Persistent reversal of addiction behavior by a transient treatment

描述(申请人提供)：钙/钙调蛋白依赖的蛋白激酶II(CaMKII)和NMDA型谷氨酸受体(NMDAR)亚单位GluN2B是长时程增强(LTP)的两个中央调节因子，LTP是一种突触可塑性形式，被认为是生理和不良适应成瘾相关学习和记忆的基础。该提案将检验这样的假设，即CaMKII/GluN2B复合体的瞬时破坏(A)持久地逆转安非他明和可卡因诱导的成瘾相关行为，(B)严重干扰记忆巩固，但不逆转已建立的记忆。这些假设是基于最近关于成瘾行为的初步数据和最近关于“正常”LTP的结果。值得注意的是，这项研究的结果将同样重要，即使它们领先于 (例如，如果我们发现抑制CaMKII活性足以逆转成瘾行为，而不需要破坏CaMKII/GluN2B复合体)。(目标1)在这里，我们将首先建立一种药物治疗，在体内破坏CaMKII/GluN2B复合体。(目的2)然后，我们将确定这种治疗在逆转成瘾行为方面的效果。这将直接决定一种治疗成瘾的新方法的可行性。(目的3)最后，我们将确定对“正常”记忆的影响，这也是临床上重要的。严重但可逆的干扰记忆获取，甚至擦除最近尚未巩固的记忆将是临床可接受的副作用。然而，虽然已经巩固的记忆的意外丧失也会产生很高的科学影响，但在治疗开发中需要克服它(例如，通过针对特定的大脑区域，即NAC，这是可以做到的，但需要更多的重症监护)。在这里，我们将使用一种非常严格的药物遗传学方法。虽然药物治疗能够确定治疗相关性(通过在预防和逆转成瘾行为之间进行时间区分)，但两个特定的小鼠突变将确定靶标特异性：CaMKII基因敲除小鼠将测试CaMKII特异性，而突变GluN2B不能结合CaMKII的小鼠将测试CaMKII/GluN2B复合体作为特定靶标。重要的是，这种方法还克服了在突变小鼠中常见的潜在补偿效应：如果由于这种补偿效应，突变小鼠仍然表现出成瘾行为(或正常或略有降低)，如果它们的突变确实是治疗的相关靶点，药物治疗应该不再对这些小鼠有效。

DESCRIPTION (provided by applicant): The Ca2+/calmodulin-dependent protein kinase II (CaMKII) and the NMDA-type glutamate receptor (NMDAR) subunit GluN2B are two central mediators of long-term potentiation (LTP), a form of synaptic plasticity thought to underlie both physiological and maladaptive addiction-related learning and memory.. The proposal will test the hypotheses that transient disruption of the CaMKII/GluN2B complex (a) persistently reverses amphetamine- and cocaine-induced addiction- related behavior and (b) acutely interferes with memory consolidation but does not reverse established memory. These hypotheses are based on recent preliminary data on addiction behavior and on recent results with "normal" LTP. Notably, the results of this study will be equally significant even if they lead to rejection of our hypotheses (for instance in case we instead find that inhibition of CaMKII activity is sufficient for reversal of addiction behavior, without requirement for disruption of th CaMKII/GluN2B complex). (Aim 1) We will here first establish a pharmacological treatment that disrupts the CaMKII/GluN2B complex in vivo. (Aim 2) Then, we will determine the effect of such treatment on reversal of addiction behavior. This will directly determine feasibility of a novel therapeutic approach to addiction. (Aim 3) Finally, we will determine the effect on "normal" memory, which is also clinically important. Acute but reversible interference with memory acquisition and even erasure of recent not yet consolidated memory would be clinically acceptable side-effects. However, while an unexpected erasure also of already consolidated memory would be of high scientific impact, it would need to be overcome in therapy development (for instance by targeting a specific brain region, i.e. the NAc, which could be done but would require more intensive care). We will here utilize a highly rigorous pharmaco-genetic approach. While the pharmacological treatment enables determining the therapeutic relevance (by enabling the temporal distinction between prevention and reversal of addiction behavior), two specific mouse mutant will determine target-specificity: a CaMKII knock-out mouse will test for CaMKII-specificity, while a mouse with mutant GluN2B incapable of CaMKII binding will test for the CaMKII/GluN2B complex as the specific target. Importantly, this approach also overcomes potential compensatory effects that are frequently seen in mutant mice: If the mutant mice still develop addiction behavior (either to normal or to somewhat reduced levels) due to such compensatory effects, the pharmacological treatment should be no longer effective in these mice, if their mutation is indeed the relevant target of the treatment.