Objective To investigate the development of directional selective ganglion cells (DSGCs) and the development of direction selective (DS) circuitry in the mouse retina.Methods Loose patch recordings were used to examine the physiological responses of DSGCs.Whole-cell patch clamp was then established to investigate the synaptic inputs and neurobiotin was infused into the cells after whole-cell recording to reveal the dendritic morphology of the DSGCs.In some cases,dual loose patch recordings or dual loose patch recording and whole-cell recordings were performed to observe the correlation of spontaneous response of a DSGC and a neighboring RGC.DSGCs are identified by their light responses or by their unique dendritic morphology in early ages.