Change in the expression of c-fos in the rat brain following sciatic nerve ligation.

A little or none is known about the direct evidence for the possible change in the expression of c-fos at the supraspinal level after nerve injury. Therefore, the present study was designed to investigate the level of c-fos in some brain regions following sciatic nerve ligation in the rat. Immunoblot analysis clearly showed that the levels of c-fos in the rat frontal cortex, thalamus and periaqueductal gray matter were significantly increased, whereas it was significantly decreased in the nucleus accumbens and ventral tegmental area. Under these conditions, the levels of c-fos in the rat amygdala, hippocampus and hypothalamus were not changed. These results provide direct evidence that the neuropathic pain-like state causes a substantial change in the expression of c-fos in the rat brain.