High Resolution Optical Recording of Bioelectric Signals

Many biological phenomena can be understood by studying the electrical signals exhibited by biological cells, such as neurons. Optical methods can, in principle, be non-invasive and therefore suitable for long-term recording of these electrical signals. However, existing optical methods such as voltage-sensitive fluorescent probes often suffer from photobleaching and therefore limit the recording time. Electrochromic optical recording (ECORE) is a method which records electrical signals by using the electrochromism exhibited by certain materials, such as the polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). In addition to being non-invasive, ECORE enables the experimenter to choose specific cells to study for extended periods of time. Here, we report on our development of a microscope-based ECORE, which uses a high-NA objective lens to increase the spatial resolution of ECORE. Microscope ECORE will enable the studying of specific regions on a cell of interest, and can therefore be used to understand cells in much more detail, shedding light on the important biological processes that are critical to life.