Though I'm still not sold on "unintegrated" primitive reflexes in older children, I'm still reading what I can about it. Your Body Works: Central Nervous System - Chiropractic Specialist Brisbane Norman Park
Neurogenesis is the process by which neurons are created. This process is most active during pre-natal development when neurogenesis is responsible for populating the growing brain. Neural stem cells (NSCs) are the self-renewing, multipotent cells that differentiate into the main phenotypes of the nervous system.
The potential for marijuana to interfere with neurodevelopment has substantial theoretical justification. The endocannabinoid system is present from the beginning of central nervous system development, around day 16 of human gestation, and is increasingly thought to play a significant role in the proper formation of neural circuitry early in brain development, including the genesis and migration of neurons, the outgrowth of their axons and dendrites, and axonal pathfinding.
Encoding asymmetry within neural circuits Miguel L. Concha, Isaac H. Bianco & Stephen W. Wilson p832 | doi:10.1038/nrn3371 Many animals, from worms to humans, show structural and functional asymmetries in their nervous systems. Concha, Bianco and Wilson describe two fundamental types of nervous system asymmetry and discuss how they emerge during development and influence behaviour. Nature Reviews Neuroscience, Dec 2012