Early gene expression in the rat cortex after experimental traumatic brain injury and hypotension.

To determine c-fos and egr-1 mRNA levels in the rat cortex after traumatic brain injury (TBI) and TBI plus hemorrhagic hypotension (HH). Sprague–Dawley rats were subjected to TBI. HH was induced by removing 5 ml of blood from the jugular vein for a duration of 20 min. Cortical tissue was harvested at 0 and 120 min, and mRNA levels of the immediate early genes c-fos, egr-1 were obtained. Rats that sustained TBI alone had increased c-fos and egr-1 mRNA expression at 120 min that was significant. Additionally, c-fos mRNA levels after TBI alone were significantly higher than c-fos mRNA levels after TBI+HH at 120 min. Levels of egr-1 mRNA after TBI alone at 120 min were not significantly higher than egr-1 mRNA levels after TBI+HH at 120 min.