Architecture and activity-mediated refinement of axonal projections from a mosaic of genetically identified retinal ganglion cells

作者：Huberman Andrew D^*; Manu Mihai; Koch Selina M; Susman Michael W; Lutz Amanda Brosius; Ullian Erik M; Baccus Stephen A; Barres Ben A

来源：Neuron, 2008, 59(3): 425-438.

DOI：10.1016/j.neuron.2008.07.018

Our understanding of how mammalian sensory circuits are organized and develop has long been hindered by the lack of genetic markers of neurons with discrete functions. Here, we report a transgenic mouse selectively expressing GFP in a complete mosaic of transient OFF-alpha retinal ganglion cells (tOFF-alpha RGCs). This enabled us to relate the mosaic spacing, dendritic anatomy, and electrophysiology of these RGCs to their complete map of projections in the brain. We find that tOFF-alpha RGCs project exclusively to the superior colliculus (SC) and dorsal lateral geniculate nucleus and are restricted to a specific laminar depth within each of these targets. The axons of tOFF-alpha RGC are also organized into columns in the SC. Both laminar and columnar specificity develop through axon refinement. Disruption of cholinergic retinal waves prevents the emergence of columnar-but not laminar-specific tOFF-alpha RGC connections. Our findings reveal that in a genetically identified sensory map, spontaneous activity promotes synaptic specificity by segregating axons arising from RGCs of the same subtype.

• 出版日期2008-8-14