EXPRESSION OF SOLUBLE GUANYLYL CYCLASE GENE IN ADULT-RAT BRAIN

The synthesis of the intracellular messenger, cyclic GMP, is catalysed by particulate or soluble guanylyl cyclase (sGCY). sGCY is activated by nitric oxide, a compound with putative neurotransmitter functions, especially in long-term potentiation. Hybridization histochemistry wit h a probe complementary to the rat lung large (alpha 1) subunit was us ed to assess the exact localization of sGCY mRNA in the rat brain. Man y cells in the olfactory bulb contained sGCY mRNA. In the whole cerebr al cortex, sGCY mRNA was found in all layers, with a predominance in l ayers II-III. A similar pattern was found in the olfactory tuberculum, in continuation with the piriform cortex and the cortical amygdaloid nucleus. All parts of the striatum expressed sGCY mRNA. sGCY mRNA was also found in the habenula medialis, in the pinealis in some diencepha lic nuclei; and in the granule cell layers of the cerebellum: This stu dy provides a description of the normal anatomy oi sGCY gene expressio n in the rat forebrain as a basis for the study of the modulation of e xpression after physiological and pharmacological manipulations.