Immunolocalization of gaseous neurotransmitters in interneurons in the medulla oblongata in rats

Abstract

We studied groups of internuclear interneurons (IN) that are located between the magnocellular and parvocellular reticular nuclei (IN1), reticular parvocellular nucleus, the nucleus of the solitary tract (IN2), and around the reticular lateral nucleus (IN3) that expreßs the neuronal NO-synthase, cystathionine ß-synthase, or heme oxygenase-2 in the medulla oblongata of Wistar rats using histochemical and immunohistochemical methods. We found local differences in the organization of INs. These differences were evident between IN1 cells, a cell group that consists of a relatively large number of large neurons, including giant cells, and IN2–IN3 cells. In interneurons of the latter two IN groups, we found significantly higher concentrations of cells and intensity of immunohistochemical staining. The local differences between the cells that contain cystathionine ß-synthase were less pronounced than between other gaseous neurotransmitter interneurons. These data indicate that the internuclear interneurons have the structure that is necessary for the successful management of integration processes in the brain.