“Once development was ended, the fonts of growth and regeneration of the axons and dendrites dried up irrevocably. In the adult centres, the nerve paths are something fixed, and immutable: everything may die, nothing may be regenerated.”     Santiago Ramon y Cajal, 1928

This model put forward by Nobel prize winning neuroscientist Ramon y Cajal was the scientific consensus held, that is to say that the concept of new neurons being born after brain development did not happen, the brain does not regenerate, rather, neurons go into apoptosis throughout life and are not replaced. That was of course until the techniques evolved to prove otherwise.

The possibility of neurogenesis, the concept whereby the brain does indeed regenerate neurons, that new neurons are born throughout life facilitating neuroplasticity, was proposed over 30 years after Ramon y Cajal’s influential statement, by Joseph Altman.