Intrasplenic injections of α-bungarotoxin increase, while injections of the nAChRa7 agonist PNU-282987 decrease, TBI-induced BBB permeability. A, Timeline for inrasplenic infusions, CCI, and BBB assessment. B, Summary results indicating that splenic injections of α-bungarotoxin (α-Bgtx; n = 5) significantly increase Evans Blue dye extravasation into the brain compared with injured animals receiving intrasplenic vehicle (Veh; n = 5) injections. C, Intrasplenic injections of PNU-282987 (30 μg; α7^agonist; n = 7) significantly reduce Evans Blue dye extravasation compared with injured animals injected intrasplenically with vehicle (n = 8). *p < 0.05 by t test between vehicle- and α-bungarotoxin-treated (B) or PNU-282987-treated (C) animals. D, Evans Blue dye extravasation in splenectomized brain-injured rats treated with vehicle, α-bungarotoxin (500 ng, s.c.), or PNU-282987 (3 mg/kg, i.p.) did not differ between the groups. Data are presented as the percentage vehicle-treated injured group; and data are reported as the mean ± SEM.