In vivo imaging of zebrafish retina

Neuronal circuits of the vertebrate retina are organized into stereotyped laminae. This orderly arrangement makes the retina an ideal model system for imaging studies aimed at understanding how circuits assemble during development. In particular, live-cell imaging techniques are readily applied to the developing retina to monitor dynamic changes over time in cell structure and connectivity. Such imaging studies have collectively revealed novel strategies by which retinal neurons contact their presynaptic and postsynaptic partners to establish synaptic connections. We describe here the procedures developed in our laboratory for confocal and multiphoton live-cell imaging of the developing retina using in vivo preparations. Zebrafish larvae are an ideal specimen for in vivo imaging experiments as they can be made to remain transparent throughout development. Isolated retinal cells can be readily labeled by DNA injection into the one-cell staged embryo, or via transplantation of fluorescently labeled cells from stable transgenics.