title: Ultrasensitive fluorescent proteins for imaging neuronal activity.
abstract: Fluorescent calcium sensors are widely used to image neural activity. Using structure-based mutagenesis and neuron-based screening, we developed a family of ultrasensitive protein calcium sensors (GCaMP6) that outperformed other sensors in cultured neurons and in zebrafish, flies and mice in vivo. In layer 2/3 pyramidal neurons of the mouse visual cortex, GCaMP6 reliably detected single action potentials in neuronal somata and orientation-tuned synaptic calcium transients in individual dendritic spines. The orientation tuning of structurally persistent spines was largely stable over timescales of weeks. Orientation tuning averaged across spine populations predicted the tuning of their parent cell. Although the somata of GABAergic neurons showed little orientation tuning, their dendrites included highly tuned dendritic segments (5-40-µm long). GCaMP6 sensors thus provide new windows into the organization and dynamics of neural circuits over multiple spatial and temporal scales.
authors.affiliation: Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA.
authors.forename: Tsai-Wen
authors.initials: TW
authors.lastname: Chen
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Wardill
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Stefan R
authors.initials: SR
authors.lastname: Pulver
authors.forename: Sabine L
authors.initials: SL
authors.lastname: Renninger
authors.forename: Amy
authors.initials: A
authors.lastname: Baohan
authors.forename: Eric R
authors.initials: ER
authors.lastname: Schreiter
authors.forename: Rex A
authors.initials: RA
authors.lastname: Kerr
authors.forename: Michael B
authors.initials: MB
authors.lastname: Orger
authors.forename: Vivek
authors.initials: V
authors.lastname: Jayaraman
authors.forename: Loren L
authors.initials: LL
authors.lastname: Looger
authors.forename: Karel
authors.initials: K
authors.lastname: Svoboda
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D002478:Cells, Cultured; D049229:Dendritic Spines / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry*; D059330:GABAergic Neurons / Q000378:metabolism; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D057054:Molecular Imaging; D016296:Mutagenesis; D015202:Protein Engineering; D017966:Pyramidal Cells / Q000378:metabolism / Q000502:physiology; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology
chemical_list: D002135:Calcium-Binding Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D002118:Calcium