[Polysynaptic components of the early somato-sympathetic reflex response in the lumbar white rami communicantes]

The second and third components of early somatosympathetic relfex discharge were studied in anesthetized cats. Polysynaptic components of the early somatosympathetic and propriospinal somatosomatic discharges were compared. Evidence was found that these reflexes have both common and specialized interneurons in their central polysynaptic chains. It is suggested that the components of the early somatosympathetic reflex are formed by different types of sympathetic preganglionic neurons, namely the second component by neurons of the lateral horns and the third one--by neurons detected in the lateral part of intermediate zone (axonal velocity less than 1.5 m/s). A classification of sympathetic preganglionic neurons is presented.