Changes in immunoreactivity of orexin-A-positive neurons after intravenous lipopolysaccharide injection.

Background: Orexins are neuromediators that help regulate many different physiological processes; however, their role in regulating immune system functioning is unclear. This study sought to investigate the distribution of orexin in hypothalamic orexin-containing neurons during the first 6 hours after an intravenous injection of a lipopolysaccharide.

Material/methods: Orexin-containing neurons were detected by immunohistochemistry (avidin-biotin) on frontal sections from the brains of intact rats and rats after injections of either saline or lipopolysaccharide.