Optimization of a GCaMP Calcium Indicator for Neural Activity Imaging

Akerboom, J., Chen, T.W., Wardill, T.J., Tian, L., Marvin, J.S., Mutlu, S., Calderón, N.C., Esposti, F., Borghuis, B.G., Sun, X.R., Gordus, A., Orger, M.B., Portugues, R., Engert, F., Macklin, J.J., Filosa, A., Aggarwal, A., Kerr, R.A., Takagi, R., Kracun, S., Shigetomi, E., Khakh, B.S., Baier, H., Lagnado, L., Wang, S.S., Bargmann, C.I., Kimmel, B.E., Jayaraman, V., Svoboda, K., Kim, D.S., Schreiter, E.R., and Looger, L.L.
The Journal of neuroscience : the official journal of the Society for Neuroscience   32(40): 13819-13840 (Journal)
Registered Authors
Baier, Herwig, Engert, Florian, Lagnado, Leon, Orger, Mike
MeSH Terms
  • Animals
  • Astrocytes/chemistry
  • Astrocytes/ultrastructure
  • Caenorhabditis elegans
  • Calcium Signaling*
  • Crystallography, X-Ray
  • Drosophila melanogaster/growth & development
  • Female
  • Fluorescent Dyes/analysis
  • Fluorescent Dyes/chemistry*
  • Fluorometry/methods*
  • Genes, Synthetic
  • Genetic Vectors
  • Green Fluorescent Proteins/analysis
  • Green Fluorescent Proteins/chemistry*
  • Green Fluorescent Proteins/genetics
  • Green Fluorescent Proteins/isolation & purification
  • HEK293 Cells/chemistry
  • HEK293 Cells/ultrastructure
  • Hippocampus/chemistry
  • Hippocampus/cytology
  • Humans
  • Larva
  • Lasers
  • Mice
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Neuroimaging/methods*
  • Neuromuscular Junction/chemistry
  • Neuromuscular Junction/ultrastructure
  • Neurons/chemistry*
  • Neurons/physiology
  • Neurons/ultrastructure
  • Neuropil/chemistry
  • Neuropil/physiology
  • Neuropil/ultrastructure
  • Olfactory Receptor Neurons/chemistry
  • Olfactory Receptor Neurons/physiology
  • Olfactory Receptor Neurons/ultrastructure
  • Peptides/analysis
  • Peptides/chemistry*
  • Peptides/genetics
  • Photic Stimulation
  • Protein Conformation
  • Rats
  • Recombinant Fusion Proteins/analysis
  • Recombinant Fusion Proteins/chemistry
  • Recombinant Fusion Proteins/genetics
  • Retinal Bipolar Cells/chemistry
  • Retinal Bipolar Cells/physiology
  • Retinal Bipolar Cells/ultrastructure
  • Synaptic Transmission*
  • Zebrafish/growth & development
23035093 Full text @ J. Neurosci.

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. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

Genes / Markers
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes