Fluorescence imaging of transgenic zebrafish embryos

The embryonic zebrafish is a nearly ideal model system in which to use time-lapse imaging to study the development of the vertebrate nervous system in vivo. The embryos are small and transparent, they develop externally and rapidly, and the embryonic central nervous system is relatively simple and highly stereotyped. With the refinement of green fluorescent protein (GFP) as a genetically encoded fluorescent tag of neuronal proteins, along with advances in imaging technology, it is possible to follow the cellular and molecular events underlying development as they occur in the living embryo. This protocol describes methods for imaging synapse formation in embryonic zebrafish. Injection of DNA into early embryos is followed by mounting of the transgenic embryos in agarose and then time-lapse data collection.