The intermediolateral gray columns in the spinal cord of Macaca mulatta

The mean length of spinal segments in Macaca mulatta varied from 0.55 to 1.4 cm. Upper thoracic and lumbar segments were shorter; middle and distal thoracic segments are longer. The intermediolateral gray column extended from the middle of the eighth cervical to the fourth lumbar spinal segments. This column as observed in the serially cut cross-sections varied in shape and in position in different regions of the spinal cord. The mean counts of intermediolateral neurons in the males were significantly higher than females (P less than 0.001) and varied from segment to segment. Their number was slightly higher on the right side and funicular cells were more numerous in male spinal cords than in females. The neurons were of varied shapes from fusiform to multipolar and measured from 7.5 to 25 micrometers in size.