Adult bone marrow stromal cells administered intravenously to rats after traumatic brain injury migrate into brain and improve neurological outcome

To measure effect of bone marrow stromal cells (MSCs) administered i.v, on rats subjected to traumatic brain injury (TBI), we injected MSCs labeled by BrdU into the tail vein 24 h after TBI and sacrificed rats 15 days later. The neurological severity score (NSS) and the Rotarod test were used to eva luate neurological function. The distribution of the donor cells in brain, heart, lung. kidney, liver and spleen were analyzed in recipient rats using immunohistochemical staining. MSCs injected i.v. significantly reduced mot or and neurological deficits compared with control groups by day 15 after T BI. The cells preferentially entered and migrated into the parenchyma of th e injured brain and expressed the neuronal marker NeuN and the astrocytic m arker GFAP. MSCs were also found in other organs and primarily localized to the vascular structures, without any obvious adverse effects. Our data sug gest that i.v. administration of MSCs may be useful in the treatment of TBI . NeuroReport 12:559-563 (C) 2001 Lippincott Williams & Wilkins.