Post-injury administration of (±)-rolipram increased IgG immunoreactivity in the ipsilateral parietal cortex. Animals received vehicle (5% ethanol) or (±)-rolipram (3 mg/kg, i.v.) 30 min or 3 hr after TBI, and then once per day (i.p.) for 3 days. Sections were immunostained for endogenous IgG levels (A). Images were taken at bregma level −4.3 mm. Scale bars 250 μm. The intensity of IgG immunostaining was quantified in the parietal cortex (B). Endogenous IgG levels were significantly increased in (±)-rolipram-treated animals as compared to vehicle-treated animals. Mean ± SEM, n = 7 vehicle-treated animals, n = 5 (±)-rolipram-treated 30 min post-injury animals, n = 5 (±)-rolipram-treated 3 hr post-injury animals, *P < 0.05, **P < 0.01, ***P < 0.001 for TBI+vehicle versus TBI+rolipram.