Role of adenylate cyclase 1 in retinofugal map development.

The development of topographic maps of the sensory periphery is sensitive to the disruption of adenylate cyclase 1 (AC1) signaling. AC1 catalyzes the production of cAMP in a Ca2+/calmodulin-dependent manner, and AC1 mutant mice (AC1−/−) have disordered visual and somatotopic maps. However, the broad expression of AC1 in the brain and the promiscuous nature of cAMP signaling have frustrated attempts to determine the underlying mechanism of AC1-dependent map development.

Receptive field mosaics of retinal ganglion cells are established without visual experience.

A characteristic feature of adult retina is mosaic organization: a spatial arrangement of cells of each morphological and functional type that produces uniform sampling of visual space. How the mosaics of visual receptive fields emerge in the retina during development is not fully understood. Here we use a large-scale multielectrode array to determine the mosaic organization of retinal ganglion cells (RGCs) in rats around the time of eye opening and in the adult.

Go with the flow -- but only in one direction.

Retinotopic maps form prior to the development of vision, when retinal waves serve as a robust source of correlated neural activity. Two recent studies provide critical insights into the features of retinal waves that may be instructive for the formation of retinotopic maps.