Chemoaffinity in the orderly growth of nerve fiber patterns and connections.

Sperry's chemoaffinity hypothesis, which states that neurons make connections with their targets based on interactions with specific molecular markers^[1] and, therefore, that the initial wiring diagram of an organism is (indirectly) determined by its genotype. The markers are generated during cellular differentiation and aid not only with synaptogenesis, but also act as guidance cues for their respective axon."  Digital facsimile from PubMedCentral at this link.