The distribution of nitric oxide synthase positive cerebrospinal fluid-contacting neurons in the surrounding region of the third ventricle in the rat

NOS positive CSF-contacting neurons were scattered at the surrounding region of the third ventricle,from anterior ventral area to posterior dorsal area.These neurons could be classified in four types.They were located in the ependymal layer,subependymal layer.Some of them were located where there was some distance to the ependyma,but they had some processes protruded into the third ventricle.In the anterior parts of posterior magnocellar paraventricular nuclei and medial magnocellar paraventricular nuclei,there were a large number of NOS positive fibers extending to the third ventricle,mixing with or contacting processes of NOS positive CSF-contacting neurons.