[Structural organization of preganglionic sympathetic neurons]

Distribution of marked preganglionic neurons over spinal nuclei and segments was studied in cats with the aid of microinjections of the horse-radish peroxidase into the cranial cervical ganglion. The major part of these neurons were revealed in the main part of the intermediolateral nucleus. A somewhat lesser number of the cells were found in the funicular part of the nucleus. In the T1 segment they constituted about 90% of cells containing the peroxidase. Other neurons were localized in the paraependymal and intercalative nuclei. In longitudinal sections of the spinal cord, the preganglionic sympathetic neurons projecting their axons into the cranial cervical ganglion, form a rostro-caudal chain made of small ensembles of cells.