Soluble guanylyl cyclase appears in a specific subset of periglomerular cells in the olfactory bulb.

In the brain, nitric oxide acts as an atypical messenger in cellular nonsynaptic transmission. In the olfactory bulb, this gas is produced at the level of the olfactory glomeruli by a subpopulation of periglomerular cells that participates in the first synaptic relay of the olfactory information between the olfactory nerve and the dendritic tufts of principal cells. It has been proposed that nitric oxide modulates intraglomerular synaptic integration of sensory inputs, but its specific role in the glomerular circuitry remains to be understood. In this article, we demonstrate that, in the glomerular circuits, a specific subset of periglomerular cells, most of them expressing the calcium binding protein calbindin D-28 k, expresses the beta1 subunit of the soluble guanylyl cyclase. These cells could be the targets for the action of nitric oxide at the glomerular level via activation of soluble guanylyl cyclase and production of cGMP.