Title Probing biological dynamics and the brain with light.
Abstract Neurons and many other cells communicate and compute with electrical signals that unfold on millisecond timescales. Traditionally, these dynamics have been studied with electrodes that directly measure voltage, but such techniques are limited in spatial coverage and invasiveness. In this talk, I will describe how optical tools, such as optogenetics and voltage imaging, are transforming our ability to both control and observe electrical activity in living neural tissue. By genetically targeting light-activated proteins to specific cell types and subcellular structures, we can use light to perturb membrane potential with millisecond precision and image the resulting voltage dynamics across extended neuronal arborizations. I will illustrate how these methods reveal voltage integration in cortical dendrites, resolve back-propagating action potentials, and open new windows on how neurons compute and communicate. More broadly, this work reflects how advances in optical physics are reshaping our ability to interrogate computation in living matter.