On the synaptogenic sequence in the chick retina

摘要

AbstractStudy of the developing chick retina with the electron microscope revealed that dyad ribbon synapses begin to form in the inner plexiform layer before synaptic ribbons begin to appear in photoreceptor terminals of the outer plexiform layer. This centrifugal (inner to outer) sequence of synaptogenesis in the predominantly cone retina of the chick differs from the centripetal sequence that has been reported for the predominantly rod retinas of the mouse and rat. This difference does not favor the hypothesis, suggested by others, that the photo‐receptor may influence the maturation of inner retinal elements. The different patterns of synaptogenesis are discussed briefly with reference to anatomical differences between the retinas of different specie