Izumi Hironori, Ishimoto Tetsuya, Yamamoto Hiroshi, Mori Hisashi
Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.
Division of Animal Resources and Development, Life Science Research Center, University of Toyama, Toyama, 930-0194, Japan.
BMC Neurosci. 2017 Jan 23;18(1):18. doi: 10.1186/s12868-017-0335-6.
Bioluminescence imaging (BLI) is a powerful technique for monitoring the temporal and spatial dynamics of gene expression in the mouse brain. However, the black fur, skin pigmentation and hair regrowth after depilation of mouse interfere with BLI during developmental and daily examination. The aim of this study was to extend the application of Arc-Luc transgenic (Tg) mice to the BLI of neuronal activity in the mouse brain by introducing the hairless (HL) gene and to examine Arc-Luc expression at various developmental stages without interference from black fur, skin pigmentation, and hair regrowth.
The Arc-Luc Tg HL mice were established by crossing the Tg C57BL/6 mouse strain with the HL mouse strain. Under physiological and pathological conditions, BLI was performed to detect the signal intensity changes at various developmental stages and at an interval of <7 days. The established Arc-Luc Tg HL mice exhibited clear and stable photon signals from the brain without interference during development. After surgical monocular deprivation during visual-critical period, large signal intensity changes in bioluminescence were observed in the mouse visual cortex. Exposure of mice to a novel object changed the photon distribution in the caudal and rostral cerebral areas. The temporal pattern of kainic-acid-induced Arc-Luc expression showed biphasic changes in signal intensity over 24 h.
This study showed the advantages of using the mutant HL gene in BLI of Arc expression in the mouse brain at various developmental stages. Thus, the use of the Arc-Luc Tg HL mice enabled the tracking of neuronal-activity-dependent processes over a wide range from a focal area to the entire brain area with various time windows.
生物发光成像（BLI）是一种用于监测小鼠大脑中基因表达时空动态的强大技术。然而，小鼠的黑色皮毛、皮肤色素沉着以及脱毛后的毛发再生在发育和日常检查过程中会干扰BLI。本研究的目的是通过引入无毛（HL）基因来扩展Arc-Luc转基因（Tg）小鼠在小鼠大脑神经元活动BLI中的应用，并在不受黑色皮毛、皮肤色素沉着和毛发再生干扰的情况下检查不同发育阶段的Arc-Luc表达。
通过将Tg C57BL/6小鼠品系与HL小鼠品系杂交建立了Arc-Luc Tg HL小鼠。在生理和病理条件下，进行BLI以检测不同发育阶段以及间隔小于7天的信号强度变化。所建立的Arc-Luc Tg HL小鼠在发育过程中大脑发出清晰且稳定的光子信号，不受干扰。在视觉关键期进行单眼剥夺手术后，在小鼠视觉皮层观察到生物发光信号强度的大幅变化。将小鼠暴露于新物体后，尾侧和头侧脑区的光子分布发生改变。 kainic酸诱导的Arc-Luc表达的时间模式在24小时内显示出信号强度的双相变化。
本研究展示了在不同发育阶段的小鼠大脑Arc表达BLI中使用突变HL基因的优势。因此，使用Arc-Luc Tg HL小鼠能够在从局部区域到整个脑区的广泛范围内，通过不同时间窗追踪神经元活动依赖性过程。
