de Carvalho Luana Martins, Chen Hu, Sutter Mason, Lasek Amy W
bioRxiv. 2023 Jan 28:2023.01.27.525899. doi: 10.1101/2023.01.27.525899.
Compulsive alcohol drinking is a key symptom of alcohol use disorder (AUD) that is particularly resistant to treatment. An understanding of the biological factors that underly compulsive drinking will allow for the development of new therapeutic targets for AUD. One animal model of compulsive alcohol drinking involves the addition of bitter-tasting quinine to an ethanol solution and measuring the willingness of the animal to consume ethanol despite the aversive taste. Previous studies have demonstrated that this type of aversion-resistant drinking is modulated in the insular cortex of male mice by specialized condensed extracellular matrix known as perineuronal nets (PNNs), which form a lattice-like structure around parvalbumin-expressing neurons in the cortex. Several laboratories have shown that female mice exhibit higher levels of aversion-resistant ethanol intake but the role of PNNs in females in this behavior has not been examined. Here we compared PNNs in the insula of male and female mice and determined if disrupting PNNs in female mice would alter aversion-resistant ethanol intake. PNNs were visualized in the insula by fluorescent labeling with agglutinin (WFA) and disrupted in the insula by microinjecting chondroitinase ABC, an enzyme that digests the chondroitin sulfate glycosaminoglycan component of PNNs. Mice were tested for aversion-resistant ethanol consumption by the addition of sequentially increasing concentrations of quinine to the ethanol in a two-bottle choice drinking in the dark procedure. PNN staining intensity was higher in the insula of female compared to male mice, suggesting that PNNs in females might contribute to elevated aversion-resistant drinking. However, disruption of PNNs had limited effect on aversion-resistant drinking in females. In addition, activation of the insula during aversion-resistant drinking, as measured by c-fos immunohistochemistry, was lower in female mice than in males. Taken together, these results suggest that neural mechanisms underlying aversion-resistant ethanol consumption differ in males and females.
强迫性饮酒是酒精使用障碍（AUD）的一个关键症状，尤其难以治疗。了解导致强迫性饮酒的生物学因素将有助于开发针对AUD的新治疗靶点。一种强迫性饮酒的动物模型是在乙醇溶液中添加苦味奎宁，并测量动物在有厌恶味道的情况下饮用乙醇的意愿。先前的研究表明，这种抗厌恶饮酒行为在雄性小鼠的岛叶皮质中受到一种特殊的浓缩细胞外基质——神经元周围网（PNN）的调节，PNN在皮质中围绕表达小白蛋白的神经元形成晶格状结构。几个实验室已经表明，雌性小鼠表现出更高水平的抗厌恶乙醇摄入量，但PNN在雌性小鼠这种行为中的作用尚未得到研究。在这里，我们比较了雄性和雌性小鼠岛叶中的PNN，并确定破坏雌性小鼠的PNN是否会改变抗厌恶乙醇摄入量。通过用凝集素（WFA）进行荧光标记在岛叶中可视化PNN，并通过显微注射软骨素酶ABC破坏岛叶中的PNN，软骨素酶ABC是一种消化PNN中硫酸软骨素糖胺聚糖成分的酶。通过在黑暗中的双瓶选择饮水程序中向乙醇中依次增加奎宁浓度来测试小鼠的抗厌恶乙醇消耗量。与雄性小鼠相比，雌性小鼠岛叶中的PNN染色强度更高，这表明雌性小鼠中的PNN可能导致抗厌恶饮酒增加。然而，破坏PNN对雌性小鼠的抗厌恶饮酒影响有限。此外，通过c-fos免疫组织化学测量，雌性小鼠在抗厌恶饮酒期间岛叶的激活低于雄性小鼠。综上所述，这些结果表明，抗厌恶乙醇消耗的神经机制在雄性和雌性中有所不同。
