Cover legend: This image shows a view of an isolated, whole-mounted retina in which a small percentage of retinal ganglion cells express yellow fluorescent protein (YFP) driven by a Thy-1 promoter. The fluorescent marker fills the dendrites, cell body, and axon of each Thy-1-YFP-expressing cell. False colors denote the relative depth of ganglion cell processes starting from the ganglion cell bodies progressing to the outer lamina of the inner plexiform layer (IPL). Red denotes regions of cells at the inner edge of the retina. The red globular spheres reveal the ganglion cell bodies. The long thin processes show the axons that lead from the cell bodies to the optic nerve head. The processes that have some resemblance to "bursts of fireworks" are dendrites that arborize in the IPL. Blue processes denote dendrites that arborize in the deeper, outer laminar region, of the IPL and receive synaptic inputs from OFF bipolar cells. Dendrites receiving inputes from ON bioplar cells are color-coded yellow to orange and arborize in the inner laminar region of the IPL. At early postnatal ages, dendritic arbors are spread diffusely throughout the inner and outer laminas of the IPL. During postnatal development, the arbors are actively refined to narrower, monolaminated structures. This refinement process is retarded by visual deprivation and accelerated by BDNF/TrkB signaling. For more information, see the article by Liu et al. in this issue (pages 7256–7267).