Effect of neuregulin-1 on histopathological and functional outcome after controlled cortical impact in mice

Neuregulin-1 is a pleiotropic endogenous growth factor that is neuroprotective in experimental models of cerebral ischemia. We tested the hypothesis that pretreatment with neuregulin-1 would be similarly protective after traumatic brain injury in mice. Mice were administered neuregulin-1 or equal amounts of vehicle intravenously immediately before controlled cortical impact. Injured mice were subjected to motor and cognitive testing, and brain tissue loss was quantitated at 4 weeks. Compared to vehicle, pretreatment with neuregulin-1 had no effect on brain tissue loss, motor function, or acquisition of a spatial learning task. However, neuregulin-1 treated mice showed improved retention of spatial memory versus vehicle-treated mice in subsequent probe trials (p<0.05). These proof-of-principle data suggest that neuregulin-1 may improve some functional outcomes after brain trauma. Further studies are therefore warranted to more carefully explore molecular mechanisms, dose-responses, and relationships between morphological outcome and long-term recovery.