細胞内カルシウムイメージング①基礎編　培養細胞におけるカルシウムイメージング

抄録

Intracellular calcium (Ca²⁺) serves as a ubiquitous second messenger, governing diverse cellular functions such as muscle contraction, signal transduction, secretion, gene expression, and cell death. The spatiotemporal profiles of Ca²⁺ signals vary widely with cell type, mode of stimulation, and subcellular domain. Ca²⁺ imaging permits direct visualization of these dynamics and is an indispensable approach for monitoring cellular physiology. This article outlines fundamental approaches for Ca²⁺ imaging in cultured cells. Two principal classes of fluorescent Ca²⁺ indicators—chemical dyes and genetically encoded sensors—are introduced, with brief explanation of their operating principles. Mechanisms underlying Ca²⁺ signal generation in response to extracellular cues are described, together with their manifestation as organized patterns such as Ca²⁺ waves and oscillations. Key aspects of image analysis and signal quantification are addressed, including definition of regions of interest, normalization of fluorescence signals, and distinction between local and global responses. Particular attention is given to the interpretation of Ca²⁺ dynamics in the context of cellular function. Ca²⁺ imaging reveals cellular activity beyond membrane excitability, providing valuable insights in both basic research and biomedical applications. This concise guide is intended for researchers, students, and clinicians seeking to implement in vitro Ca²⁺ imaging for the study of cellular physiology.