Abstract
Activity-dependent neural plasticity is well known in the development of visual cortical circuitry. However, little is known about the role of neural plasticity in the developing retina. In light of recent findings that light deprivation alters the development of synaptic pathway in the mouse retina, I examined if visual experience is required for the maturation of the ON-OFF direction selective ganglion cells (DSGCs) in the rabbit retina. The DSGCs of whole mount rabbit retinas raised in the normal light-dark cycle and in the constant darkness were recorded extracellularlly at various postnatal stages. Receptive field properties, such as direction selectivity, velocity tuning, classical center-surround interaction, motion-induced surround inhibition, and contextual tuning were carefully characterized. Recorded cells were subsequently injected with Neurobiotin for morphological identification and examining the tracer coupling pattern. My results reveal that visual experience is not critical for the maturation of classical receptive field properties of the DSGCs, such as direction selectivity and velocity tuning. However, dark-reared animals showed altered surround inhibition mediated by amacrine cells in the inner retina. In addition, the DSGCs showed similar dendritic features and tracer coupling patterns in both normal-reared and dark-reared rabbits. Taken together, this study indicates that the effect of visual experience on retinal circuit maturation is not as profound as cortical circuit maturation.