Abstract 1. Distributional patterns of radioactivity in the choroid plexuses and the paraphysis cerebri of Rana esculenta following intraventricular injections of tritiated noradrenaline have been studied autoradiographically. 2. Strong autoradiographic labeling was found in the diencephalic and myelencephalic choroid plexuses, whereas the paraphysis was hardly labeled. These differences in labeling suggest that the paraphysis lacks (an) uptake mechanism(s) for monoamines. 3. An always higher labeling of the diencephalic choroid plexus in comparison with the myelencephalic choroid plexus in each frog may be explained in terms of differences in metabolism and function.