Noradrenaline nerve terminals in the hippocampal region of the rat and the guinea pig

Summary The hippocampal region of the rat has been studied with the histochemical fluorescence method for demonstration of catecholamines and 5-hydroxytryptamine. Noradrenalin nerve terminals of characteristic appearance were observed throughout the region, but the density of the terminals in the various areas differed considerably. The highest amount of terminals were seen in the hilus of the area dentata of the rat. Otherwise, noradrenalin nerve terminals constitute a small percentage of the afferents to the hippocampal region. Noticeable differences existed between rat and guinea-pig. In both species there was a conspicuous lack of stratification and delineation of areas as compared with the pictures seen with most other methods, which have revealed precise architectonic patterns.Supported by a Research Grant (12X-715-02) from the Swedish Medical Research council and by a Grant from Stiftelsen M. Bergwalls Minne.