NGF levels decrease in the spinal cord and dorsal root ganglion after spinal hemisection

To examine changes in nerve growth factor (NGF) levels in spinal cord and dorsal root ganglia (DRG) after spinal injury, male Sprague-Dawley rats weighing 150-175 g were given spinal hemisections. NGF content was measured at various post-surgical times and compared with naive controls (n=4 per time point) in the spinal cord, DRG and blood serum by ELISA techniques (Promega). Levels of NGF in the blood serum were significantly increased 8-fold at 48 h but were significantly decreased in the spinal cord and DRG by 2- to 4-fold until 7 days postsurgery (ANOVA, p<0.05). Contrary to accepted dogma, spinal injury results in decreased levels of NGF in the spinal cord and DRG following spinal injury.