Improved calcium imaging in transgenic mice expressing a troponin C–based biosensor

Fluorescent Ca2+ indicator proteins (FCIPs) are attractive tools for studying Ca2+ dynamics in live cells. Here we describe transgenic mouse lines expressing a troponin C (TnC)-based biosensor. The biosensor is widely expressed in neurons and has improved Ca2+ sensitivity both in vitro and in vivo. This allows FCIP-based two-photon Ca2+ imaging of distinct neurons and their dendrites in vivo, and opens a new avenue for structure-function analysis of intact neuronal circuits.

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