The matching between neuron and target is determined before the axons of the motor neurons grow out of the spinal cord. Types and timing of transcription factor expression can determine the fate of the nerve cells and also motor nerve cells. Pattern formation in connections between neurons Pathway selection Target selection Address selection Differentiation of neurons involves axon outgrowth. Once the neurons have migrated they develop axons and dendrites which grow toward and make connections with appropriate targets. Cell surface molecules of neighboring cells regulate growth cone behavior.
Contact guidance plays a role in promoting axon outgrowth in some cases.
Fibers in the ECM that are under tension selectively attract growing neurites Guidance by adhesive gradients Figure 8.6. Small spots of laminin on glial cells along the pathway of some axons may mark the pathway for axons to grow. Multiple binding sites on the laminin molecule allow for interactin with a wide variety of cells. Isoleucine rich segment of the B 2 chain is essential for some neurite outgrowth. A glycoprotein portion of the laminin binds with a glycosyltransferase on growth cones.