2.2. Induction of Experimental Traumatic Brain Injury TBI

Mice were anesthetized with an intraperitoneal injection (i.p.) of ketamine and xylazine (2.6 and 0.16 mg/kg body weight, respectively). Traumatic brain injury was performed by a controlled cortical impactor (CCI) as already described [36]. Briefly, a craniotomy was made encompassing bregma and lambda and between the sagittal suture and the coronal ridge of the right hemisphere, using a Micro motor hand piece and drill. The ensuing bone flap was removed and on the exposed cortex a cortical contusion was produced using the controlled impactor device Impact OneTM Stereotaxic impactor a for CCI (Leica, Milan, Italy) [37]. Subsequently, the skin incision was sutured, and 2% lidocaine jelly was applied to the lesion to minimize any possible discomfort. Both the WT and FPR1-deficient animals were treated with penicillin (40,000 U/kg) for five days after TBI to rule out confounding effects by bacterial infections (in the long-term series) [38].