Optimization of a GCaMP calcium indicator for neural activity imaging

Jasper Akerboom, Tsai Wen Chen, Trevor J. Wardill, Lin Tian, Jonathan S. Marvin, Sevinç Mutlu, Nicole Carreras Calderón, Federico Esposti, Bart G. Borghuis, Xiaonan Richard Sun, Andrew Gordus, Michael B. Orger, Ruben Portugues, Florian Engert, John J. Macklin, Alessandro Filosa, Aman Aggarwal, Rex A. Kerr, Ryousuke Takagi, Sebastian KracunEiji Shigetomi, Baljit S. Khakh, Herwig Baier, Leon Lagnado, Samuel S.H. Wang, Cornelia I. Bargmann, Bruce E. Kimmel, Vivek Jayaraman, Karel Svoboda, Douglas S. Kim, Eric R. Schreiter, Loren L. Looger

Research output: Contribution to journalArticlepeer-review

940 Scopus citations


Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by severalfold, creating a family of "GCaMP5" sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2- to 3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3.GCaMP5allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

Original languageEnglish (US)
Pages (from-to)13819-13840
Number of pages22
JournalJournal of Neuroscience
Issue number40
StatePublished - Oct 3 2012


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