Research has already demonstrated that adult neurogenesis occurs in specific areas of the brain. I wouldn&#x27;t be surprised if neurogenesis occurs throughout the whole brain, in response to proper stimulus.  I suspect that the reason it doesn&#x27;t generally occur is that it is more efficient to grow new synapses between existing neurons than to differentiate stem cells into new neurons.<p>By analogy, muscles can undergo a fairly good amount of hypertrophy just via protein synthesis of contractile elements.  However, in response to severe stress&#x2F;trauma, satellite cells (a form of quiescent, partially differentiated stem cell) merge with muscle cells; the result of this is a muscle cell with a greater potential for hypertrophy.<p>Perhaps neurogenesis and only occurs under special conditions (like muscular myonuclear addition), such as extremely novel stimulus, or great mental effort.  This would make it extremely difficult to induce experimentally.