在 ChAT::Cre+ 大鼠中,基线时改变的运动、焦虑相关和注意力任务表现与囊泡乙酰胆碱转运体和相关蛋白过表达的多个基因拷贝相关。
Altered motor, anxiety-related and attentional task performance at baseline associate with multiple gene copies of the vesicular acetylcholine transporter and related protein overexpression in ChAT::Cre+ rats.
机构信息
Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.
Department of Psychology, The Behavioral and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge, UK.
出版信息
Brain Struct Funct. 2019 Dec;224(9):3095-3116. doi: 10.1007/s00429-019-01957-y. Epub 2019 Sep 10.
Transgenic rodents expressing Cre recombinase cell specifically are used for exploring mechanisms regulating behavior, including those mediated by cholinergic signaling. However, it was recently reported that transgenic mice overexpressing a bacterial artificial chromosome containing choline acetyltransferase (ChAT) gene, for synthesizing the neurotransmitter acetylcholine, present with multiple vesicular acetylcholine transporter (VAChT) gene copies, resulting in altered cholinergic tone and accompanying behavioral abnormalities. Since ChAT::Cre+ rats, used increasingly for understanding the biological basis of CNS disorders, utilize the mouse ChAT promotor to control Cre recombinase expression, we assessed for similar genotypical and phenotypical differences in such rats compared to wild-type siblings. The rats were assessed for mouse VAChT copy number, VAChT protein expression levels and for sustained attention, response control and anxiety. Rats were also subjected to a contextual fear conditioning paradigm using an unconditional fear-inducing stimulus (electrical foot shocks), with blood samples taken at baseline, the fear acquisition phase and retention testing, for measuring blood plasma markers of hypothalamic-pituitary-adrenal gland (HPA)-axis activity. ChAT::Cre+ rats expressed multiple mouse VAChT gene copies, resulting in significantly higher VAChT protein expression, revealed anxiolytic behavior, hyperlocomotion and deficits in tasks requiring sustained attention. The HPA-axis was intact, with unaltered circulatory levels of acute stress-induced corticosterone, leptin and glucose. Our findings, therefore, reveal that in ChAT::Cre+ rats, VAChT overexpression associates with significant alterations of certain cognitive, motor and affective functions. Although highly useful as an experimental tool, it is essential to consider the potential effects of altered cholinergic transmission on baseline behavior in ChAT::Cre rats.
表达 Cre 重组酶的转基因啮齿动物细胞特异性用于探索调节行为的机制,包括胆碱能信号介导的那些机制。然而,最近有报道称,过表达含有胆碱乙酰转移酶 (ChAT) 基因的细菌人工染色体的转基因小鼠,用于合成神经递质乙酰胆碱,表现出多个囊泡乙酰胆碱转运体 (VAChT) 基因拷贝,导致胆碱能张力改变和伴随的行为异常。由于 ChAT::Cre+ 大鼠越来越多地用于理解中枢神经系统疾病的生物学基础,利用小鼠 ChAT 启动子来控制 Cre 重组酶表达,因此我们评估了与野生型兄弟姐妹相比,这种大鼠是否存在类似的基因型和表型差异。评估了大鼠的小鼠 VAChT 拷贝数、VAChT 蛋白表达水平以及持续注意力、反应控制和焦虑。还使用无条件恐惧诱导刺激(电脚刺激)对大鼠进行了情境恐惧条件反射范式,在基线、恐惧获得阶段和保留测试时采集血样,以测量下丘脑-垂体-肾上腺 (HPA) 轴活性的血浆标志物。ChAT::Cre+ 大鼠表达多个小鼠 VAChT 基因拷贝,导致 VAChT 蛋白表达显著增加,表现出焦虑样行为、过度活跃和需要持续注意力的任务缺陷。HPA 轴完好,循环中急性应激诱导的皮质酮、瘦素和葡萄糖水平没有改变。因此,我们的研究结果表明,在 ChAT::Cre+ 大鼠中,VAChT 过表达与某些认知、运动和情感功能的显著改变相关。尽管作为一种实验工具非常有用,但在 ChAT::Cre 大鼠中,考虑改变胆碱能传递对基线行为的潜在影响是至关重要的。