[Intravital optical imaging of bone and cartilage tissues].

Intravital optical imaging technique is a promising method that allows us to investigate complex vital phenomena in vivo . In particular, discovery and development of unique fluorescent proteins and smart fluorescent dyes in conjunction with appropriate equipment such as two-photon microscopy and image processing software allow visualization of the behavior and function of bone and cartilage-related cells as well as the microenvironment of the cells in bone and cartilage in living animals. Here we show recent technological development and issues of the intravital optical imaging and the application of the fluorescent imaging approaches to bone and cartilage biology.