Developmental origin and fate of meso-diencephalic dopamine neurons.

Specific vulnerability of substantia nigra compacta neurons as compared to ventral tegmental area neurons, as emphasized in Parkinson's disease, has been studied for many years and is still not well understood. The molecular codes and mechanisms that drive development of these structures have recently been studied through the use of elegant genetic ablation experiments. The data suggested that specific genes at specific anatomical positions in the ventricular zone are crucial to drive development of young neurons into the direction of the dopaminergic phenotype. In addition, it has become clear the these dopaminergic neurons are present in the diencephalon and in the mesencephalon and that they may contain a specific molecular signature that defines specific subsets in terms of position and function. The data indicate that these specific subsets may explain the specific response of these neurons to toxins and genetic ablation.