Zebrafish (Danio rerio) develop rapidly and is visually responsive by about 4 days postfertilization. Because the embryo can be maintained relatively transparent throughout this period, we are able to track structural changes in zebrafish retinal neurons from the time of their genesis until they form circuits. Retinal neurons are visualized by expression of fluorescent protein driven by cell-specific promoters. Labeling is achieved either by injection or DNA at the one-cell stage, or in stable transgenic lines. Currently, we are investigating the mechanisms that regulate the structural and functional connectivity of the inner and outer retina. Using time-lapse confocal and multiphoton imaging approaches, we have recently discovered that some zebrafish retinal ganglion cells adopt an unexpected strategy to establish contact with their synaptic partners. Read more