Sanes_1993_Curr.Opin.Neurobiol_3_67

Topographically organized patterns of connectivity occur throughout the central and peripheral nervous systems. It is commonly supposed that gradients of recognition molecules underlie this form of synaptic specificity. Recent studies have led to new ideas about how such gradients might arise in the retinotectal system, and initiated molecular analyses of position-dependent gene expression in the peripheral motor system.