The membrane electric field is thought to be involved in the various cellular functions, in addition to the generations and conductions of impulses seen in the excitable cells, Techniques visualizing local electric field are therefore essential to comprehensively understand its role. In the last two decades, there have been considerable progress in the imaging technique detecting electrical activities in the excitable cells, but the applications have been limited only to a part of diverse electric phenomena.
In this research, we focus on two subjects on visualization of local electric field, explorations of new “targets” and “principles”. In the former, we seek to develop techniques to visualize the membrane electric field in the endoplasmic reticulum membranes and the inner membrane of the mitochondria. It is expected that the relationship between electrical activity and physiological functions as well as pathological conditions in these organelle membranes can be elucidated. In the latter, we study physical properties of fluoresce proteins focusing on their interactions with metal thin film and particles, and their potential applications to cell biology.