The Pharmacology of Sympathetic Preganglionic Neurons

Abstract

The sympathetic preganglionic neurons (SPNs) are found in the intermediolateral (IML) cell column of the thoraco lumbar spinal cord. In cats, presynaptic fibers that originate in the medulla and higher centers approach the IML cell column primarily from the lateral funiculus (Rethelyi, 1972). Three types of presynaptic vesicles suggesting the presence of several different transmitters have been identified in the terminals (Rethelyi, 1972). Dahlstrom and Fuxe (1965) found that in rats, a high density of monoamine-containing bulbospinal fibers terminated in close proximity to SPNs. A similar distribution of monoamine neurons was reported for cats, and fibers associated with these terminals were located in the lateral funiculus (Coote and Macleod, 1974b; Coote et al., 1981). Descending adrenergic (Soller, 1977) and serotonergic (Anden et al., 1964; Mensah et al., 1974) pathways have also been described for amphibia.