Developmental plasticity of photoreceptors.
During development, retinal ganglion cells undergo conspicuous structural remodeling as they gradually attain their mature morphology and connectivity. Alterations in their dendritic organization and in their axonal projections can also be achieved following early insult to their targets or their afferents. Other retinal cell types are thought not to display this same degree of developmental plasticity. The present review will consider the evidence, drawn largely from recent experimental studies in the carnivore retina, that photoreceptors also undergo structural remodeling, extending their terminals transiently into inner plexiform layer before retracting to the outer plexiform layer. The determinants of this transient targeting to the inner plexiform layer are considered, and the role of cholinergic amacrine cells is discussed. The factors triggering this retraction are also considered, including the concurrent maturational changes in outer segment formation and in the differentiation of the outer plexiform layer. These results provide new insight into the life history of the photoreceptor cell and its connectivity, and suggest a transient role for the photoreceptors in the circuitry of the inner retina during early development, prior to the onset of phototransduction.
Reese
Benjamin E
BE
Neuroscience Research Institute, Department of Psychology, University of California at Santa Barbara, Santa Barbara, CA 93106-5060, USA. breese@psych.ucsb.edu
D000375:Aging / Q000502:physiology*; D025042:Amacrine Cells / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000502:physiology; D002335:Carnivora / Q000502:physiology; D006801:Humans; D009473:Neuronal Plasticity; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*