Changes of mRNA of Group III metabotropic glutamate receptors after diffuse brain injury and diffuse brain injury with secondary brain insults. The bar graph shows no statistical significance was found in the number of mGluR positive neurons among sham-operated control and SBI alone groups (P > 0.05). Compared with that in sham-operated control and SBI alone groups, the expression of mGluR4, 7, 8 in the DBI alone group increased significantly 1 hour after injury, and reached the highest level after 6 hours. The expression of mGluR4, 7, 8 in the DBI with SBI group was even higher than that in the DBI alone group. However, there were no significant changes in mGluR6 expression after injury. aP < 0.05 vs sham-operated control and SBI alone groups. bP < 0.05 vs DBI alone group.