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The last 45 years have witnessed dramatic evolution of optical and molecular tools for neuronal membrane potential (Vm) imaging to reveal how neurons process and transmit information.  Fluorescent Vm reporters offer a critical complement to widely used calcium reporters, which track slow, downstream correlates of action potential generation. In contrast, Vm reporters enable direct imaging of action potentials, subthreshold synaptic inputs, and resting state fluctuations. Despite these scientific advantages, fluorescence transients generated by membrane potential reporters are orders of magnitude smaller and faster than calcium reporter transients, rendering them difficult to image. High signal-to-noise resolution of fast Vm transients necessitates maximizing fluorescence excitation and collection rates. I will present optical systems designed to maximize this “photon budget” for high signal-to-noise Vm imaging in mammalian neurons.