Cannabinoid signaling system: does it play a function in cell proliferation and migration, neuritic elongation and guidance and synaptogenesis during brain ontogenesis?

The cannabinoid signaling system is located during brain development in a position concordant with playing a modulatory function in the regulation of neuronal and glial cell proliferation and migration, survival of neural progenitors, axonal elongation and synaptogenesis, and differentiation of oligodendrocytes and formation of myelin. This assumption is based on the fact that CB1 receptors and their ligands emerge early in brain development and are transiently expressed in certain brain regions that play key roles in these processes. We have recently proposed that this modulatory action might be exerted through regulating L1 and other cell adhesion molecules, that are also key elements for those processes. The present commentary will address these two questions trying to summarize all the available evidence and to suggest the future directions for research.