Expression of Cre recombinase in dopaminoceptive neurons

Background: Dopamine-activated signaling regulates locomotor and emotional responses and alterations in dopamine-signaling are responsible of several psychomotor disorders. In order to identify specific functions of these pathways, the Cre/loxP system has been used. Here, we describe the generation and the characterization of a transgenic mouse line expressing the Cre recombinase in dopaminoceptive neurons. To this purpose, we used as expression vector a 140 kb yeast artificial chromosome (YAC) containing the dopamine DI receptor gene (DrdIa). Results: In the chosen line, DICre, the spatio-temporal pattern of Cre expression closely recapitulated that of the endogenous DrdIa gene, as assessed by immunohistological approaches in embryonic and adult stages. Efficiency of recombination was confirmed by crossing DICre with three different loxP lines (CrebI(loxP), CaMKIVloxP and GR(loxP)) and with the R26R reporter. In the three loxP lines studied, recombination was restricted to the area of Cre expression. Conclusion: In view of the patterns of recombination restricted to the major dopaminoceptive regions as seen in the context of the CREB, CaMKIV and GR mutations, the DICre line will be a useful tool to dissect the contributions of specific genes to biological processes involving dopamine signaling.