Fair overview. This is not a simple question that can be answered with a Yes or No. It is a quantitative question at three levels:

1. What brain regions and neuron types?

2. What is the precise gain or turn-over of numbers of neurons per year?

3. What rates of change per year per type per brain region?

For humans we have essentially no hard data with which to address these three questions for structure or neuron type. Sadly this is also true for mouse with still shaky exception of the dentate gyrus and rostral migratory stream of one strain of mouse—C57BL/6J.

I still regard Pasko Rakic’s work as definitive—that in adult rhesus monkey females injected 4 to 6 times over several years with high levels of tritiated thymidine there is no evidence of adult neurogenesis in any brain region. Sure: proving the negative is a bitch, but these studies place a very low limit on levels of adult neurogenesis in primates—even in hippocampus. Meaninglessly low levels. And I have scanned this collection with Rakic.

The end of this review is on-the-mark: There are still very good reasons to be enthused about the POTENTIAL of adult neurogenesis. Being able to induce useful levels of adult neurogenesis would be a game changer. But reality and potential are different beasts.