Phenotype, compartmental organization and differential vulnerability of nigral dopaminergic neurons.
The degeneration of nigral dopaminergic (DA-) neurons is the histopathologic hallmark of Parkinson's disease (PD), but not all nigral DA-cells show the same susceptibility to degeneration. This starts in DA-cells in the ventrolateral and caudal regions of the susbtantia nigra (SN) and progresses to DA-cells in the dorsomedial and rostral regions of the SN and the ventral tegmental area, where many neurons remain intact until the final stages of the disease. This fact indicates a relationship between the topographic distribution of midbrain DA-cells and their differential vulnerability, and the possibility that this differential vulnerability is associated with phenotypic differences between different subpopulations of nigral DA-cells. Studies carried out during the last two decades have contributed to establishing the existence of different compartments of nigral DA-cells according to their neurochemical profile, and a possible relationship between the expression of some factors and the relative vulnerability or resistance of DA-cell subpopulations to degeneration. These aspects are reviewed and discussed here.
González-Hernández
Tomás
T
Department of Anatomy, Faculty of Medicine, University of La Laguna, 38071, La Laguna, Tenerife, Spain. tgonhern@ull.es
Afonso-Oramas
Domingo
D
Cruz-Muros
Ignacio
I
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D009474:Neurons / Q000502:physiology*; D010641:Phenotype; D013378:Substantia Nigra / Q000166:cytology* / Q000502:physiology*
D004298:Dopamine