They are misrepresenting the state of knowledge in that field. It has indeed been known -- since the 90s -- that there is ongoing neurogenesis in the human brain after birth. However, it is also well-known that these new neurons are produced in regions of the brain that are not relevant to Parkinson's. The specific neurons that are lost in this disease, from a region of the brain known as the substantia nigra, are not normally replaced by ongoing neurogenesis.
(I say "not normally" because redirecting neurogenesis to supply new neurons to the substantia nigra, as a treatment for Parkinson's disease, has been an ongoing area of research for decades.)
Note also that this research study was done with zebrafish, whose neurobiology is dramatically different from humans.
(I say "not normally" because redirecting neurogenesis to supply new neurons to the substantia nigra, as a treatment for Parkinson's disease, has been an ongoing area of research for decades.)
Note also that this research study was done with zebrafish, whose neurobiology is dramatically different from humans.