The two papers covered in the Hot Paper feature1 are interesting, but the real question is whether the animal models are of any use as models for idiopathic human Parkinson disease (PD).
My own view is that the original fetal neural grafts did not work as well as people expected, not because the tissue was inappropriate, but because the notion of grafting dopaminergic cells into the striatum is itself such an imperfect approach. It is now well established2 that in PD, neuronal loss (apparently specific) occurs also in other brain regions such as the thalamus, cortex, and brainstem. Why should the transplantation of any cell type, irrespective of the source of those cells, into only one location such as the striatum fix the problem?
It should also be remembered that these grafted dopaminergic cells are being placed in a heterotopic and thus inappropriate location where they cannot receive their normal ...
