Histochemical Localization of Nitric Oxide Synthase in the Nervous System of Earthworm
WANG Xiao-An ZHENG Zhe-Min(College of Life Science,Shaanxi Normal University Xi′an 710062,China)
The distribution of nitric oxide synthase (NOS) positive cells and fibers in the nervous system of earthworm (Pheretima tschiliensis) was studied with NADPH-diaphorase histochemical method. The intense staining was localized in many neurons in the dorsal part of cerebral ganglion. The somatas and processes were stained obviously. A few weakly stained neurons were observed occasionally in subpharyngeale. A strongly NOS positive tract from ventromedial of cerebral ganglion, through circumpharyngeal nerve into subpharyngeale ganglion and all ganglia of ventral nerve chain was observed. The results of this study indicate that nitric oxide as a message molecular existes in the nervous system of Annelidan.