Figure 8.

Model for Coronin-1 function in defining two stages of final target innervation. A, Model for axon behavior in the early innervation stage: NGF-TrkA signaling in the absence of Coronin-1. NGF-TrkA acts via PI3K to promote exuberant axon branching and axon growth. B, Model for axon behavior in the late innervation stage: NGF-TrkA signaling in the presence of Coronin-1 increases calcium presumably through PLC-γ1, which inhibits axon growth and branching by suppressing signaling downstream PI3K.