Distribution of nitric oxide synthase neurons projecting fibers of dorsal raphe nucleus in rat cortex microvessels

Objective:To study the distribution of nitric oxide synthase (NOS) containing fibers from the dorsal raphe nucleus projecting to the cerebral microvessels. Methods:Totally 16 male adult SD rats were divided into 2 groups. The experimental group were microinjected with quisqualic acid, and raised for a week, then they were perfusion-fixed, the brain were sectioned and stained by the NADPH-d histochemistry. Results: The NOS-positive neurons in dorsal raphe nucleus decreased significantly by 59.1% ( P<0.001). The NOS positive terminals decreasd by 32.1% (P<0.05) in the frontal-parietal cortex,and the NOS positive terminals associated with microvessels decreased by 37.8% (P<0.01), 32.8% (P<0.05) and 39.4% (P<0.01) in occipital, temporal cortex, respectively. Conclusion: It is suggested that the NOS-containing neurons in dorsal raphe nucleus projecting to the microvessels in cerebral cortex.