Engineering genetically encoded indicators for imaging neuronal activity

To understand the endogenous roles of distinct neuron types in behavior, we need the tools and technology that will allow us to study their activation patterns in a type-specific manner and that will operate at the physiologically relevant spatiotemporal scales. We will achieve this goal by creating optical tools that can be genetically targeted to specific subtypes and are engineered to report neuronal activity with single-cell and single-spike precision. Our approach will be to:

• create recombinant protein indicators comprising neuronal activity sensors fused to fluorescent reporters,

• develop strategic and empirical methods of protein engineering with the goal of enhancing the sensitivity, kinetics, brightness, and photostability of the indicators, and

• establish an automated directed evolution workflow that selects variants with superior characteristics for downstream applications, such as spike detection and spike timing estimation, in behaving animals.