Hafenbreidel Madalyn, Pandey Surya, Briggs Sherri B, Arza Meghana, Bonthu Shalakha, Fisher Cadence, Tiller Annika, Hall Alice B, Reed Shayna, Mayorga Natasha, Lin Li, Khan Susan, Cameron Michael D, Rumbaugh Gavin, Miller Courtney A
Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, United States; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, United States; The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, United States.
Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, United States; The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL 33458, United States.
Neurobiol Learn Mem. 2023 Dec;206:107865. doi: 10.1016/j.nlm.2023.107865. Epub 2023 Nov 22.
Preclinical studies show that inhibiting the actin motor ATPase nonmuscle myosin II (NMII) with blebbistatin (Blebb) in the basolateral amgydala (BLA) depolymerizes actin, resulting in an immediate, retrieval-independent disruption of methamphetamine (METH)-associated memory in male and female adult and adolescent rodents. The effect is highly selective, as NMII inhibition has no effect in other relevant brain regions (e.g., dorsal hippocampus [dPHC], nucleus accumbens [NAc]), nor does it interfere with associations for other aversive or appetitive stimuli, including cocaine (COC). To understand the mechanisms responsible for drug specific selectivity we began by investigating, in male mice, the pharmacokinetic differences in METH and COC brain exposure . Replicating METH's longer half-life with COC did not render the COC association susceptible to disruption by NMII inhibition. Therefore, we next assessed transcriptional differences. Comparative RNA-seq profiling in the BLA, dHPC and NAc following METH or COC conditioning identified crhr2, which encodes the corticotropin releasing factor receptor 2 (CRF2), as uniquely upregulated by METH in the BLA. CRF2 antagonism with Astressin-2B (AS2B) had no effect on METH-associated memory after consolidation, allowing for determination of CRF2 influences on NMII-based susceptibility. Pretreatment with AS2B prevented the ability of Blebb to disrupt an established METH-associated memory. Alternatively, combining CRF2 overexpression and agonist treatment, urocortin 3 (UCN3), in the BLA during conditioning rendered COC-associated memory susceptible to disruption by NMII inhibition, mimicking the Blebb-induced, retrieval-independent memory disruption seen with METH. These results suggest that BLA CRF2 receptor activation during memory formation in male mice can prevent stabilization of the actin-myosin cytoskeleton supporting the memory, rendering it vulnerable to disruption by NMII inhibition. CRF2 represents an interesting target for BLA-dependent memory destabilization via downstream effects on NMII.
临床前研究表明，在基底外侧杏仁核（BLA）中用肌球蛋白抑制剂（Blebb）抑制肌动蛋白运动ATP酶非肌肉肌球蛋白II（NMII）会使肌动蛋白解聚，从而立即对成年和青少年雄性及雌性啮齿动物的甲基苯丙胺（METH）相关记忆产生与记忆提取无关的破坏作用。这种作用具有高度选择性，因为NMII抑制在其他相关脑区（如背侧海马体 [dPHC]、伏隔核 [NAc]）没有效果，也不会干扰与其他厌恶或奖赏性刺激（包括可卡因 [COC]）的关联。为了了解药物特异性选择性的机制，我们首先在雄性小鼠中研究了METH和COC脑内暴露的药代动力学差异。用COC复制METH的较长半衰期并没有使COC关联易受NMII抑制的破坏。因此，我们接下来评估了转录差异。在METH或COC条件反射后，对BLA、dHPC和NAc进行比较RNA测序分析，确定编码促肾上腺皮质激素释放因子受体2（CRF2）的crhr2在BLA中被METH独特地上调。用阿斯特辛 - 2B（AS2B）拮抗CRF2对巩固后的METH相关记忆没有影响，从而可以确定CRF2对基于NMII的易感性的影响。用AS2B预处理可阻止Blebb破坏已建立的METH相关记忆的能力。另外，在条件反射期间，在BLA中联合过表达CRF2和激动剂治疗、促肾上腺皮质激素释放激素3（UCN3），使COC相关记忆易受NMII抑制的破坏，类似于用Blebb诱导的、与记忆提取无关的METH记忆破坏。这些结果表明，雄性小鼠记忆形成过程中BLA中CRF2受体的激活可以阻止支持记忆的肌动蛋白 - 肌球蛋白细胞骨架的稳定，使其易受NMII抑制的破坏。CRF2代表了一个通过对NMII的下游作用使BLA依赖的记忆不稳定的有趣靶点。
