[Fluorescence histochemical and neurohistological investigations on the locus coeruleus of the rat (author's transl)].

The Locus coeruleus (LC) of the adult rat was investigated by means of fluorescence histochemical and rapid GOLGI impregantion technique. The majority of LC neurons displayed, as a result of application of the FALCK-HILLARP-technique and the LOREN-technique, resp, the well-known fluorescence typical of catecholamine neurons. There was lack of fluorescence within a minor portion of cells. Fluorescence histochemically, serotoninergic afferents could be shown to go up to noradrenaline-containing neurons in some cases. In the GOLGI material, 3 types of neurons could be distinguished: Polygonal neurons exhibiting somatic spines, fusiform neurons, and small-sized spine-less neurons. Based on morphological features, the polygonal neuron type is considered to represent the monoamine-containing neurons of the Locus coeruleus. It appears uncertain at present to attribute the fusiform and small spineless neuron types in a functional manner. functional implications inherent that morphological heterogeneity have been discussed.