Rational Engineering of XCaMPs, a Multicolor GECI Suite for In Vivo Imaging of Complex Brain Circuit Dynamics

Masatoshi Inoue, Atsuya Takeuchi, Satoshi Manita, Shin ichiro Horigane, Masayuki Sakamoto, Ryosuke Kawakami, Kazushi Yamaguchi, Kouhei Otomo, Hiroyuki Yokoyama, Ryang Kim, Tatsushi Yokoyama, Sayaka Takemoto-Kimura, Manabu Abe, Michiko Okamura, Yayoi Kondo, Sean Quirin, Charu Ramakrishnan, Takeshi Imamura, Kenji Sakimura, Tomomi NemotoMasanobu Kano, Hajime Fujii, Karl Deisseroth, Kazuo Kitamura, Haruhiko Bito

Research output: Contribution to journalArticlepeer-review

103 Citations (Scopus)


To decipher dynamic brain information processing, current genetically encoded calcium indicators (GECIs) are limited in single action potential (AP) detection speed, combinatorial spectral compatibility, and two-photon imaging depth. To address this, here, we rationally engineered a next-generation quadricolor GECI suite, XCaMPs. Single AP detection was achieved within 3–10 ms of spike onset, enabling measurements of fast-spike trains in parvalbumin (PV)-positive interneurons in the barrel cortex in vivo and recording three distinct (two inhibitory and one excitatory) ensembles during pre-motion activity in freely moving mice. In vivo paired recording of pre- and postsynaptic firing revealed spatiotemporal constraints of dendritic inhibition in layer 1 in vivo, between axons of somatostatin (SST)-positive interneurons and apical tufts dendrites of excitatory pyramidal neurons. Finally, non-invasive, subcortical imaging using red XCaMP-R uncovered somatosensation-evoked persistent activity in hippocampal CA1 neurons. Thus, the XCaMPs offer a critical enhancement of solution space in studies of complex neuronal circuit dynamics. Video Abstract: Quadricolor suite of genetically encoded calcium indicators for multiplex recording in the brain.

Original languageEnglish
Pages (from-to)1346-1360.e24
Issue number5
Publication statusPublished - 2019 May 16


  • PV recording
  • XCaMP
  • ckkap sequence
  • genetically encoded calcium indicators
  • multiplex imaging
  • non-invasive hippocampal recording
  • paired pre- and post-synapse recording
  • two-photon Ca imaging

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


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