Figure 10.

Schematic diagram illustrating the signaling mechanisms that control the bidirectional responses of the growth cone to BMP7 gradients. In 4–8-h neurons, BMP7 induces an attractive response through the LIMK pathway. In overnight neurons, BMP7 repels the growth cone through the CaN–SSH phosphatase pathway, which is activated by Ca²⁺ signaling through TRP channels. ADF/cofilin acts as the common downstream target of these two signaling pathways to locally regulate the actin cytoskeleton for distinct turning responses. PM, plasma membrane.