| Abstract: | Tritiated catecholamines were administered to European green frogs by means of injection into the brain cavity. Their fate within the brain was followed autoradiographically. Especially after injection of 3H-noradrenaline, considerable amounts of radioactive material were found closely associated with the liquor fibre (Reissner's fibre; LF) which is produced by the subcommissural organ. In frogs which survived 3 or 12 hours after injection, the association of radioactive material with the LF appeared to be restricted mainly to the cerebral ventricles, whereas in frogs which survived 24 hours, the radioactivity associated with the LF was most abundant well into the central canal of the spinal cord. The results indicate that the LF is able to pick up, from the cerebrospinal fluid, and bind certain catecholaminergic substances (especially noradrenaline, but not dopamine) and/or their metabolites by rather strong binding forces. The attached material is then transported by the LF into the central canal of the spinal cord, with its practically stagnant fluid content. These results confirm data known from the literature. which are indicative of the LF being involved in regulation of the composition of the fluid within the central canal, e.g. by providing this canal with catecholaminergic substances and/or by removing them from it. |
