A novel cAMP-dependent pathway activates neuronal integrin function in retinal neurons.

Retinal neurons lose the ability to attach to and extend neurites on substrata of laminin-1 (LN-1) during late embryogenesis, in a time frame that corresponds to target innervation. Although this developmental loss correlates with a modest downregulation of integrin expression, we have shown previously that these neurons use the same laminin-binding integrins for outgrowth on other laminin isoforms to which responsivity has not been lost (Ivins et al., 1998), suggesting that integrin functional states may be a critical point of regulation.