Preadolescent drd1-EGFP mice exhibit cocaine-induced behavioral sensitization.
Preadolescent drd1-EGFP mice exhibit cocaine-induced behavioral sensitization.
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青春期前的 drd1-EGFP 小鼠表现出可卡因诱导的行为过敏。
DOI：
10.1016/j.neulet.2013.09.051
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发表时间：
2014
影响因子：
2.5
通讯作者：
Kuzhikandathil,EldoV
中科院分区：
文献类型：
--
作者：
Tobón,KrishnaE;Kuzhikandathil,EldoV
在成年小鼠中，重复给予可卡因会诱导行为过敏，表现为水平运动活动增加。可卡因诱导的运动敏化已在成年小鼠中得到很好的表征。在成年动物中，D1 多巴胺受体对于介导可卡因的作用非常重要。可卡因对青春期前动物 D1 受体表达和功能的影响尚不清楚。最近描述的drd1增强型绿色荧光蛋白（drd1-EGFP）报告小鼠是进行此类机制研究的有用模型；然而，之前尚未对青春期前drd1-EGFP小鼠进行表征。在这里，我们研究了可卡因诱导的青春期前 drd1-EGFP 报告小鼠的运动敏化。从出生后第 23 天开始，我们对 todrd1-EGFP 报告小鼠和常用的 C57BL/6 小鼠连续 7 天给予 15 mg/kg 可卡因 3 次，每次间隔 1 小时。在这种方案下，两种品系的青春期前小鼠都表现出可卡因诱导的运动敏化。然而，到了第 7 天，与 C57BL/6 小鼠相比，drd1-EGFP 小鼠中可卡因诱导的运动活动维持了更长的持续时间。与 C57BL/6 小鼠相比，青春期前的 drd1-EGFP 小鼠在新环境中也表现出基础运动活性升高，并且尾状核中 D1 和 D2 多巴胺受体 mRNA 水平更高。当drd1-EGFP小鼠保持不含可卡因两周时，可卡因诱导的运动敏化并未保留，这表明在青春期前的drd1-EGFP小鼠中，可卡因诱导的变化不会持续存在。
In adult mice, repeated cocaine administration induces behavioral sensitization measured as increased horizontal locomotor activity. Cocaine-induced locomotor sensitization has been well characterized in adult mice. In adult animals, the D1 dopamine receptor is important for mediating effects of cocaine. The effect of cocaine on D1 receptor expression and function in preadolescent animals is less understood. The recently describeddrd1-enhanced green fluorescent protein (drd1-EGFP) reporter mouse is a useful model for performing such mechanistic studies; however, preadolescentdrd1-EGFP mice have not been characterized previously. Here we studied cocaine-induced locomotor sensitization in preadolescentdrd1-EGFP reporter mice. We administered 15 mg/kg cocaine three times daily at 1 h intervals for seven consecutive days beginning on postnatal day 23 todrd1-EGFP reporter mice and the commonly used C57BL/6 mice. Under this regimen, preadolescent mice of both strains exhibited cocaine-induced locomotor sensitization; however, by day 7 the cocaine-induced locomotor activity in thedrd1-EGFP mice was maintained for a longer duration compared to the C57BL/6 mice. The preadolescentdrd1-EGFP mice also exhibited elevated basal locomotor activity in a novel environment and had higher D1 and D2 dopamine receptor mRNA levels in the caudate nucleus compared to the C57BL/6 mice. The cocaine-induced locomotor sensitization was not retained when thedrd1-EGFP mice were maintained cocaine-free for two weeks suggesting that in preadolescentdrd1-EGFP mice the cocaine-induced changes do not persist.