Autonomic Efferent Neurons in the Central Nervous System

Abstract

The preganglionic neurons of the sympathetic pathway (visceral motor neurons) are located in the spinal cord, at the base of the ventral horn. They constitute a cellular column, the intermediolateral column (or nucleus), which in man reaches from the 1st thoracic to the upper lumbar segment and corresponds to the lateral horn. The rostral end of the intermediolateral nucleus of the rat (Navaratnam & Lewis, 1970), cat (Rexed, 1954; Henry & Calaresu, 1972) and man (Massazza, 1923, 1924; Gagel, 1928; Bok, 1928) is located at the limit between the cervical and thoracic spinal cord (Fig. 6). The caudal end of the cellular column is located by most authors between the first and third lumbar level. Henry and Calaresu (1972) found that the intermediolateral nucleus in the cat becomes less distinct in the lumbar levels but can be followed as far down as the fourth lumbar segment. Massazza (1923, 1924) and Bok (1928) reported that in man the intermediolateral column becomes thin in the midlumbar segments, but it extends down to the sacral spinal level where it merges with the sacral parasympathetic column.