[Morpho-histochemical characterization of the connections between the dorsal part of the lateral geniculate nucleus (LGN) and the brain stem of albino rats) (author's transl)].

After selective application of horseradish peroxidase (HRP) into the dorsal part of the lateral geniculate nucleus (LGN) of the albino rat, cells were labelled through the retrograde transport of the enzyme in the following nuclei of the brain stem: 1. Ncl. raphes linearis, 2. Nel, raphes centralis, 3. Ncl. raphes dorsalis, 4. Ncl. ventralis rostralis lemnisci lateralis, 5. Ncl. coeruleus. Using the glyoxylic acid method to demonstrate biogenic amines we could find serotonine in following areas of the brain stem: 1. region B 7 (Ncl. raphes dorsalis) positive cells; 2. region B 8 (Ncl. raphes centralis) mainly positive fibres; 3. region B 9 (dorsal of the Lemniscus medialis) a few positive cells; 4. mesencephalic reticular formation (Area cuneiformis) network-like fibre structures; 5. dorsal LGN, in the lateral part mildly fluorescing fibres, the remaining LGN showing diffuse fluorescence, 6. Substantia nigra, fluorescing cells. The monosynaptic connections between the mesencephalic raphe nuclei and the dorsal part of the LGN, demonstrated by means of the HRP-method, are characterized as being serotoninergic with the help of fluorescence histochemistry. The character of the transmitter of these connections is compared with results of biochemical and pharmacological investigations.