Recent advances in the experimental study on the production, migration and differentiation of neurons were introduced.
All neurons in the central nervous system are produced either at the matrix layer, the subependymal layer or the external granular layer. The neuroblasts, produced at these places, migrate to the respective regions to occupy their fiaal position. Each groups of neuro_is are pro 1 aced at a definite time in embryonic or early postnatal life. Granule cells are the last group of the neurons which are produced in the central nervous system. Production of the granule cells in the human cerebellar cortex is known to last until eight to twenty months of age.
In the cerebral cortex, neurons in the layer VI are produced first and those in the layer II are last. Thus the neurons occupying the outer part of the cortex are phylogenetically younger than those in the deeper.
