Localization of Fibrinogen in the Vasculo-Astrocyte Interface after Cortical Contusion Injury in Mice

Besides causing neuronal damage, traumatic brain injury (TBI) is involved in memory reduction, which can be a result of alterations in vasculo-neuronal interactions. Inflammation following TBI is involved in elevation of blood content of fibrinogen (Fg), which is known to enhance cerebrovascular permeability, and thus, enhance its deposition in extravascular space. However, the localization of Fg in the extravascular space and its possible interaction with nonvascular cells are not clear. The localization of Fg deposition in the extravascular space was defined in brain samples of mice after cortical contusion injury (CCI) and sham-operation (control) using immunohistochemistry and laser-scanning confocal microscopy. Memory changes were assessed with new object recognition and Y-maze tests. Data showed a greater deposition of Fg in the vascular and astrocyte endfeet interface in mice with CCI than in control animals. This effect was accompanied by enhanced neuronal degeneration and reduction in short-term memory in mice with CCI. Thus, our results suggest that CCI induces increased deposition of Fg in the vasculo-astrocyte interface, and is accompanied by neuronal degeneration, which may result in reduction of short-term memory.