. Cerebral Circulation: Anatomy, Distribution and Physiopathology, pp. 1-45
Authors: A. Popa-Wagner, D. Pirici, A.M. Zagrean, E. Petcu, L. Mogoanta, L. Zagrean, C.L. Rosen, R. Leon , J. Huber, Department of Experimental Neurology, Greifswald Medical School, Germany, and others)
Abstract: Age-related brain injuries are a majorause of physical and mental disabilities for which no satisfactory treatment exists. The most prevalent form of brain injury in the elderly results from stroke, which can be defined as a disruption of cerebral blood flow owing to vascular blockage or hemorrhage. Chronic hypertension and cerebral amyloid angiopathy (CAA) are the main pathologies which can induce the rupture of cerebral vessels and intracerebral hemorrhagies, as a result of degenerative changes in the vascular wall. A lot of progress has been made in this direction since the successful creation of the first mouse model for the study of Alzheimer‘s disease (AD), as the spectrum of AD pathology includes a plethora of changes found in pure cerebrovascular diseases. We describe here some of these mouse models having important vascular changes that parallel human AD pathology, and more importantly, we show how these models have helped us understand more about the mechanisms that lead to CAA formation. An important cellular event associated with reduced structural and functional recovery after stroke in aged animals is the early formation of a scar in the infarcted region that impairs subsequent neural recovery and repair. We review recent evidence showing that the rapid formation of the glial scar following stroke in aged rats is associated with premature cellular proliferation that originates primarily from the walls of capillaries in the corpus callosum adjacent to the infarcted region. After stroke several vascular mechanisms are turned-on immediately to protect the brain from further damage and help subsequent neuroregeration and functional recovery. Although vasculogenesis does occur after stroke, it is is overshadowed in its protective/restorative role by the angiogenesis and arteriogenesis. Understanding the basic mechanisms underlying functional recovery after cerebral stroke in aging subjects is likely to yield new insights into the treatment of brain injury in the clinic.