In neurobiology, human in vivo studies are prohibitive from a cost, logistical, and ethical standpoint. But to anyone who can successfully parse a neurobiology paper this is assumed knowledge.
To return the goal posts to their original location, my premise was that the title "Parkinson's gene may impair how new neurons are made throughout our lifetime" is misleading, as the neurons in question are not actually made throughout our lifetimes. The referenced paper, which uses zebrafish and a somewhat contrived cell culture model, does not provide any new evidence about actual dopaminergic neurogenesis in humans. It is fair to say that if they'd actually demonstrated such neurogenesis actually occurs, with or without PINK1, the paper wouldn't have been published in just Scientific Reports.
Okay man, cool. Let me know when your open-brain Dr. Mephisto trials disproving adult DA neurogenesis are written up in Nature
Edit: the title’s not even misleading; “Parkinson’s” modifies “gene,” not “neurons” so it’s not even saying anything about the location of these neurons or when they are being created!