ZFIN ID: ZDB-PUB-200628-8
Precision Calcium Imaging of Dense Neural Populations via a Cell-Body-Targeted Calcium Indicator
Shemesh, O.A., Linghu, C., Piatkevich, K.D., Goodwin, D., Celiker, O.T., Gritton, H.J., Romano, M.F., Gao, R., Yu, C.J., Tseng, H.A., Bensussen, S., Narayan, S., Yang, C.T., Freifeld, L., Siciliano, C.A., Gupta, I., Wang, J., Pak, N., Yoon, Y.G., Ullmann, J.F.P., Guner-Ataman, B., Noamany, H., Sheinkopf, Z.R., Park, W.M., Asano, S., Keating, A.E., Trimmer, J.S., Reimer, J., Tolias, A.S., Bear, M.F., Tye, K.M., Han, X., Ahrens, M.B., Boyden, E.S.
Date: 2020
Source: Neuron   107(3): 470-486.e11 (Journal)
Registered Authors: Ahrens, Misha, Narayan, Sujatha, Ullmann, Jeremy
Keywords: GCaMP6, GCaMP7, calcium imaging, correlation, crosstalk, in vivo imaging, microscopy, neuropil contamination, soma-targeting, two-photon microscopy
MeSH Terms:
  • Animals
  • Artifacts
  • Brain/diagnostic imaging*
  • Brain/metabolism
  • Brain/pathology
  • Calcium/metabolism*
  • Calcium-Binding Proteins
  • Cell Body/metabolism
  • Cell Body/pathology*
  • Green Fluorescent Proteins
  • Mice
  • Neurons/metabolism
  • Neurons/pathology*
  • Neuropil
  • Optical Imaging/methods*
  • Zebrafish
PubMed: 32592656 Full text @ Neuron
Methods for one-photon fluorescent imaging of calcium dynamics can capture the activity of hundreds of neurons across large fields of view at a low equipment complexity and cost. In contrast to two-photon methods, however, one-photon methods suffer from higher levels of crosstalk from neuropil, resulting in a decreased signal-to-noise ratio and artifactual correlations of neural activity. We address this problem by engineering cell-body-targeted variants of the fluorescent calcium indicators GCaMP6f and GCaMP7f. We screened fusions of GCaMP to natural, as well as artificial, peptides and identified fusions that localized GCaMP to within 50 μm of the cell body of neurons in mice and larval zebrafish. One-photon imaging of soma-targeted GCaMP in dense neural circuits reported fewer artifactual spikes from neuropil, an increased signal-to-noise ratio, and decreased artifactual correlation across neurons. Thus, soma-targeting of fluorescent calcium indicators facilitates usage of simple, powerful, one-photon methods for imaging neural calcium dynamics.