Abstract：
The development of genetically-encoded fluorescent probes for the detection of intracellular calcium ions and various neurotransmitters has progressed significantly in recent years, and there is a growing need for techniques that rapidly and efficiently image these signals in the living brain for pharmacological studies of the central nervous system. In this article, we discuss one-photon fluorescence microscopy techniques used for brain activity imaging, particularly wide-field imaging and head-mounted miniaturized microscopy, and introduce their basic principles, recent advances, and applications in pharmacological research. Wide-field calcium imaging is suitable for mesoscopic observation of cortical activity during behavioral tasks in head-fixed awake mice, while head-mounted miniaturized microscopes can be attached to the animal\'s head to image brain activity associated with naturalistic behaviors such as social behavior and sleep. One-photon microscopy allows for the development of a simple and cost-effective imaging system using an affordable excitation light source such as a light-emitting diode. Its excitation light illuminates the entire field of view simultaneously, making it easy to perform high-speed imaging using a high-sensitivity camera. In contrast, the short wavelength of the excitation light limits the field of observation to areas on or near the brain surface due to its strong light scattering. Moreover, the out-of-focus fluorescence makes it difficult to obtain images with a high signal-to-noise ratio and spatial resolution. The use of one-photon microscopy in brain activity imaging has been limited compared to two-photon microscopy, but its advantages have recently been revisited. Therefore, this technique is expected to become a useful method for pharmacologists to visualize the activity of the living brain.
摘要：
近年来,用于检测细胞内钙离子和各种神经递质的基因编码荧光探针的开发取得了显著进展,并且越来越需要快速有效地在活大脑中成像这些信号的技术，以进行中枢神经系统的药理学研究。在这篇文章中,我们讨论了用于脑活动成像的单光子荧光显微镜技术，特别是宽视场成像和头戴式微型显微镜，并介绍他们的基本原理，最近的进步，以及在药理学研究中的应用。宽场钙成像适用于头部固定清醒小鼠行为任务过程中皮层活动的介观观察,而头戴式微型显微镜可以连接到动物的头部图像与自然行为，如社会行为和睡眠相关的大脑活动。单光子显微镜允许使用负担得起的激发光源（如发光二极管）开发简单且具有成本效益的成像系统。它的激发光同时照亮整个视场，使其易于使用高灵敏度相机进行高速成像。相比之下,激发光的短波长由于其强烈的光散射而将观察区域限制在大脑表面上或附近的区域。此外，离焦荧光使得难以获得具有高信噪比和空间分辨率的图像。与双光子显微镜相比，单光子显微镜在脑活动成像中的使用受到限制，但它的优势最近被重新审视。因此,这种技术有望成为药理学家可视化活大脑活动的有用方法。
