Stochastic Ca(2+) Waves that Propagate Through the Neuroepithelium in Limited Distances of the Brain and Retina Imaged with GCaMP3 in Zebrafish Embryos
- Authors
- Okamoto, S., Nakagawa, M., and Hatta, K.
- ID
- ZDB-PUB-130906-1
- Date
- 2013
- Source
- Zoological science 30(9): 716-723 (Journal)
- Registered Authors
- Hatta, Kohei
- Keywords
- Ca2+transient, skeletal muscle, cell division, calmodulin, spinal neuron, IP3-receptor
- MeSH Terms
-
- Animals
- Behavior, Animal
- Brain/metabolism*
- Calcium/physiology*
- Calcium Signaling
- Calmodulin/chemistry
- Calmodulin/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/antagonists & inhibitors
- Luminescent Proteins/metabolism*
- Muscle, Skeletal/embryology
- Muscle, Skeletal/metabolism
- Neurons/metabolism
- Retina/metabolism*
- Zebrafish/embryology*
- PubMed
- 24004077 Full text @ Zool. Sci.
Ca2+ plays important roles in animal development and behavior. Various Ca2+ transients during development have been reported in non-neuronal tissues, mainly by using synthesized calcium indicators. Here we used GCaMP3, a genetically encoded calcium indicator, to monitor stochastic Ca2+ waves, in zebrafish embryos. To express GCaMP3 systemically throughout the body, its mRNA was injected into fertilized eggs. In the neuroepithelium of developing anterior brain and retina at 12–20 hours post-fertilization, we found spontaneously occurring stochastic Ca2+ waves. Each Ca2+ wave typically appeared in a randomly distributed spot, spread for 5–60 sec to form an area whose position and size varied each time with a diameter ranging from 10 to 160 µm, and then shrank and decreased to 50% brightness in 4–67 sec. A precise examination of the cellular distribution using Nipkow disk multibeam confocal laser scanning indicated that the Ca2+ waves spread cell by cell. 2-APB, IP3-receptor inhibitor, but not carbenoxolone, a gap junction blocker, inhibit these Ca2+ waves. Stronger fluorescence was found in the cytoplasm compared to the nuclei in the resting cells, and localized fluorescence was observed at the spindle poles in dividing cells. Ca2+ waves also spread through the dividing cells. Our results reveal a novel type of cell-to-cell communication through the neuroepithelium in the developing zebrafish brain and retina, distinct from communication through neuron-neuron circuits. Our findings also indicated that GCaMP3 was useful for monitoring both stochastic and behavior-related Ca2+ waves in the nervous system and skeletal muscles in zebrafish embryos.