The role of DCX and LIS1 in migration through the lateral cortical stream of developing forebrain.

During forebrain development the lateral cortical stream (LCS) supplies neurons to structures in the ventral telencephalon including the amygdala and piriform cortex. In the current study, we used spatially directed in utero electroporation and RNAi to investigate mechanisms of migration to the ventral telencephalon. Cells labeled by in utero electroporation of the lateral ventricular zone migrated into the LCS, and entered the lateral neocortex, piriform cortex and amygdala, where they differentiated primarily as pyramidal neurons. RNAi of DCX or LIS1 disrupted migration into amygdala and piriform cortex and caused many neurons to accumulate in the external and amygdalar capsules. RNAi of LIS1 and DCX had similar as well as distinguishable effects on the pattern of altered migration. Combinatorial RNAi of LIS1 and DCX further suggested interaction in the functions of LIS1 and DCX on the morphology and migration of migrating neurons in the LCS. Together, these results confirm that the LCS contributes pyramidal neurons to ventral forebrain structures and reveals that DCX and LIS1 have important functions in this major migratory pathway in the developing forebrain.