Defasciculate

The second is called "parallel bypass" where SNb defasciculates but continues to parallel the ISN. The third is termed the "stall" where SNb defasciculates and stops on its way to the muscle field.

In Slit2 mutant mice, motor nerves prematurely defasciculate into smaller bundlers in various muscles, unlike those in wild type that stay in compact fascicle until they reach the middle of muscle fibers.