Immunological response and tissue loss in a rodent model of chronic traumatic brain injury treated with resolvin.

backgroundTraumatic brain injury (TBI) triggers neuroinflammation both acutely and chronically, the latter which might be involved in neurodegenerative disorders. Resolvins are neuroinflammatory modulators, hypothesized to improve resolution of inflammation. This study sought to explore sustained immunological responses after delayed treatment with resolvins utilizing novel tools for automated cellular assessments. MATERIALS AND

methodsTwenty-five rodents (Sprague-Dawley rats) were exposed to a penetrating TBI, following which delayed treatment with resolvin was initiated. Assessments of tissue loss, and persistent neuroinflammatory activation, was assessed at 6 weeks post-injury utilizing histological and immunohistochemical methods. We also developed a novel computational tool to count and automatically assess cell counts across treatment groups.

resultsThe TBI model elicited a substantial brain injury, as expected. The lesion cavity volume was not affected by resolvin or vehicle treatment. Notably, both microglial and macrophage responses were also similar between treatment groups, as deemed by state-of-the-art computational models.

conclusionResolvins administered in a delayed fashion following severe TBI did not affect the extent of chronic microglial or macrophage responses, but warrants future corroboration. Dosing and timing of resolvin treatment warrants further study.