MIDBRAIN DOPAMINERGIC-NEURONS IN THE MOUSE - COLOCALIZATION WITH CALBINDIN-D-28K AND CALRETININ

The calcium-binding proteins Calbindin-D-28k and calretinin are co-loc alized with dopamine in some of the midbrain dopaminergic neurons in t he rat and monkey; the present study sought to examine the pattern of co-localization in the mouse. Double immunofluorescence staining proce dures were used for tyrosine hydroxylase (a dopaminergic cell marker) and Calbindin-D-28k or calretinin. Midbrain dopaminergic neurons were examined at four rostrocaudal levels, and the percentage of cells that contained both tyrosine hydroxylase and either of the two calcium-bin ding proteins was determined in nucleus A8 (retrorubral field), nucleu s A9 (substantia nigra pars compacta, pars reticulata and pars lateral is) and nucleus A10 (nucleus paranigralis, ventral tegmental area, int erfascicular nucleus, central linear nucleus). The two calcium-binding proteins were distributed similarly in midbrain dopaminergic neurons in the several nuclear groups that comprise nuclei AS, A9 and A10. The calcium binding proteins were found in the majority (50-100%) of nucl eus A10 neurons, whereas in nuclei A8 and A9 (except for the substanti a nigra pars lateralis) less than 40% of the cells contained either ca lcium-binding protein. The pattern of co-localization in the mouse is similar to that reported for the rat and monkey. The calcium-binding p roteins mark the population of midbrain dopaminergic neurons that are less vulnerable to degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetra hydropyridine mouse model of Parkinson's disease. Copyright (C) 1996 I BRO.