Optical imaging of cortical activity in the living brain

Abstract

Recent advances in two optical imaging techniques are helping scientists develop a better understanding of the development, organization and function of the cortex for sensory information processing and higher brain functions. These new clues to a better understanding of the brain are obtained as the collective activity of million of neurons is imaged simultaneously, rather than recording the individual activity of single neurons using classical electrophysiological techniques. In the first method, voltage sensitive dyes are used to image the flow of information from one cortical site to the next in real time. The second method is based on monitoring intrinsic changes in the optical properties of active brain tissue, permitting high resolution imaging of the functional architecture of cortex. These developments have only been realized as newer optical and imaging technologies are being adopted in this rapidly expanding field.