Prolonged, brain-wide expression of nuclear-localized GCaMP3 for functional circuit mapping.

TitleProlonged, brain-wide expression of nuclear-localized GCaMP3 for functional circuit mapping.
Publication TypeJournal Article
Year of Publication2014
AuthorsKim, CK, Miri, A, Leung, LC, Berndt, A, Mourrain, P, Tank, DW, Burdine, RD
JournalFront Neural Circuits
Volume8
Pagination138
Date Published2014
ISSN1662-5110
KeywordsAction Potentials, Animals, Animals, Genetically Modified, Brain, Brain Mapping, Cell Nucleus, Cells, Cultured, Eye Movements, Fluorescence, HEK293 Cells, Humans, Nerve Tissue Proteins, Neural Pathways, Neurons, Nuclear Proteins, Rats, Transfection, Zebrafish, Zebrafish Proteins
Abstract

<p>Larval zebrafish offer the potential for large-scale optical imaging of neural activity throughout the central nervous system; however, several barriers challenge their utility. First, ~panneuronal probe expression has to date only been demonstrated at early larval stages up to 7 days post-fertilization (dpf), precluding imaging at later time points when circuits are more mature. Second, nuclear exclusion of genetically-encoded calcium indicators (GECIs) limits the resolution of functional fluorescence signals collected during imaging. Here, we report the creation of transgenic zebrafish strains exhibiting robust, nuclearly targeted expression of GCaMP3 across the brain up to at least 14 dpf utilizing a previously described optimized Gal4-UAS system. We confirmed both nuclear targeting and functionality of the modified probe in vitro and measured its kinetics in response to action potentials (APs). We then demonstrated in vivo functionality of nuclear-localized GCaMP3 in transgenic zebrafish strains by identifying eye position-sensitive fluorescence fluctuations in caudal hindbrain neurons during spontaneous eye movements. Our methodological approach will facilitate studies of larval zebrafish circuitry by both improving resolution of functional Ca(2+) signals and by allowing brain-wide expression of improved GECIs, or potentially any probe, further into development.</p>

DOI10.3389/fncir.2014.00138
Alternate JournalFront Neural Circuits
PubMed ID25505384
PubMed Central IDPMC4244806
Grant List5R90DA023419-04 / DA / NIDA NIH HHS / United States
DK090065 / DK / NIDDK NIH HHS / United States
MH099647 / MH / NIMH NIH HHS / United States
NS062798 / NS / NINDS NIH HHS / United States
R01 DK090065 / DK / NIDDK NIH HHS / United States
R01 HD048584 / HD / NICHD NIH HHS / United States
R01 MH099647 / MH / NIMH NIH HHS / United States
R01HD048584 / HD / NICHD NIH HHS / United States
R01MH060651 / MH / NIMH NIH HHS / United States
/ / Howard Hughes Medical Institute / United States