Protein expression and brain plasticity after transient middle cerebral artery occlusion in the rat

After a stroke, both animals and humans can regain lost function. The molecular basis of this functional plasticity is unknown. In this manuscript, we describe developmental protein expression in the ischemic brain after stroke. We present data on the expression and localization of select cell-cycle proteins, a cytoskeletal protein [microtubule-associated protein-2 (MAP-2)], a growth-associated protein (GAP-43) and a neurofilament protein (nestin) in ischemic rat brain. These proteins are upregulated and selectively localized to periinfarct regions of brain for at least 4 weeks after middle cerebral artery occlusion in the rat. The expression of these developmentally regulated proteins suggests that the ischemic brain reverts to a fetal stage after stroke, possibly in an attempt to restructure and regain function.