Emergence of realistic retinal networks in culture promoted by the superior colliculus

The developing retina is characterized by 'retinal waves', spontaneous depolarizations that propagate through a developing network of interneurons and retinal ganglion cells. Although the circuitry underlying retinal waves is well characterized, the secreted factors that are critical for its normal development are not defined. Dissociated cell culture provides an ideal system for defining these factors; however, it is difficult to recapitulate retinal circuitry in culture. Here we demonstrate that by culturing dissociated retinal neurons in the presence of cells from the superior colliculus (SC), retinal neurons form networks that are similar to those described in the intact retina. Whole-cell voltage clamp recordings reveal the presence of a spontaneously active network of interneurons. In addition, we observed spontaneous, propagating activity reminiscent of that observed in the intact retina. We propose that the presence of factors secreted from the SC results in the development of networks that reproduce critical features of the intact retina.