Recent Advances in Fluorescence Imaging of Bioactive Molecules in Neurons and in Vivo

Abstract

Brain possesses a unique chemical composition and reactivity. Bioactive molecules in brains including metal ions, reactive oxygen species, neurotransmitters and neurotransmitter hydrolases play multifarious and pivotal roles in the function of brain. These molecules keep steady-state concentrations for maintaining the brain's structure and function. However, the abnormal changes in bioactive molecular levels are associated with various brain diseases such as Parkinson's disease, Alzheimer's disease, depression, and so on. Therefore, to explore the concentration and regulation of those molecules in brains is particularly essential for revealing the mysteries of brains and understanding the occurrence and development of brain diseases. Fluorescence imaging is a powerful tool to track bioactive molecules in neurons and in brain because of its remarkable advantages, such as high temporal-spatial resolution, excellent biocompatibility and high sensitivity. In recent years, with the development of fluorescence imaging technology, a variety of fluorescent probes for brain and neurons imaging have been reported. In this review, we summarize the progress of molecular probes, nanoprobes and protein probes for the detection of bioactive molecules in neurons and in brain. Furthermore, future research for fluorescence imaging are prospected.