Expression of messenger RNA for the prostaglandin D receptor in the leptomeninges of the mouse brain

The localization of prostaglandin D receptor in the mouse brain was examined by in situ hybridization histochemistry. The autoradiography showed significant hybridization signals of mRNA for prostaglandin D receptor in the leptomeninges covering the surface of the brain, but not in neurons or glia in the brain parenchyma. This finding was confirmed by Northern blot analysis using mRNA prepared from either the whole brain with the leptomeninges, brain parenchyma without the leptomeninges or the leptomeninges alone. A weak signal corresponding to the major 3.5-kbp transcript was detected in the whole brain. This band was significantly enriched in the leptomeninges, but was not detected in the brain parenchyma. These results suggest that prostaglandin D receptor is most highly, if not exclusively, expressed in the leptomeninges of the mouse brain.