Imaging Nervous System Activity

AbstractOptical imaging methods rely upon visualization of three types of signals: (1) intrinsic optical signals, including light scattering and reflectance, birefringence, and spectroscopic changes of intrinsic molecules, such as NADH or oxyhemoglobin; (2) changes in fluorescence or absorbance of voltage‐sensitive membrane dyes; and (3) changes in fluorescence or absorbance of calcium‐sensitive indicator dyes. Of these, the most widely used approach is fluorescent microscopy of calcium‐sensitive dyes. This unit describes protocols for the use of calcium‐sensitive dyes and voltage‐dependent dyes for studies of neuronal activity in culture, tissue slices, and en‐bloc preparations of the central nervous system.