论文部分内容阅读
In the rabbit and mouse retina, some ON-OFF direction selective ganglion cells (DSGCs) showed tracer coupling when injected with neurobiotin, and a majority of morphological ON-OFF DSGCs showed coupling in the early postnatal rabbit retina.It is not clear whether the coupled ON-OFF DSGCs belong to the same subtype, if they do, what preferred directions they exhibit? And whether the coupling in early development is heterologous and is gradually becoming homologous? In this study, we showed that after postnatal day 15 (P15), all coupled ON-OFF DSGCs exhibited preferred directions to superior.At P13, the ON-OFF DSGCs with preferred directions to posterior also showed coupling.Furthermore, every ON-OFF DSGC in all four subtypes exhibited coupling at P12.These results illustrated a rapid decoupling process around eye opening.Using a transgenic mouse line with GFP exclusively expressed in the posterior subtype of ON-OFF DSGCs, we demonstrated that ON-OFF DSGCs with the preferred directions to anteriorand posterior are coupled together at P12, forming a "metapopulation"separated from the other two subtypes.Our results suggest that early in development there exist subtype-specific dendro-dendrite/soma interactions among the four classes of mouse ON-OFF DSGCs.The mechanism of how different subtypes of juvenile ON-OFF DSGCs recognize each other still needs investigation.