STRUCTURAL ORGANIZATION OF BLOOD VESSELS IN SUBVENTRICULAR ZONE
OF THE BRAIN AFTER ISCHEMIA.
Federal State Institution "Scientific Research Institute of Experimental Medicine", North-West Branch of the Russian Academy of Medical Sciences, St. Petersburg, Russia; firstname.lastname@example.org
Subventricular zone of the brain is a small area located along the lateral wall of the lateral ventricles. It is this area in mammals where processes of neurogenesis are going throughout the life of the organism. Study of neurogenesis probabilities and mechanisms regulating its intensity using pharmacological agents in ischemic brain lesions can contribute to find new approaches to the treatment of serious diseases such as ischemic stroke and postischemic encephalopathy. One of the unexplored issues in this direction is the study of early reorganization of blood vessels in the area of transient ischemia. The purpose of this study was to examine the structural organization and cytochemical characteristics of blood vessels in the subventricular zone in the early (48 h) postischemic period. Experiments were performed on adult male Wistar rats. Unilateral focal ischemia was performed at the Department of Pathophysiology of Pavlov St. Petersburg State Medical University according to protocol described in details elsewhere [Korzhevsky DE, Kirik OV Baysa AE, Vlasov TD Bull. Exp. Biol. Med., 2009, v.147, № 2, P. 255-256]. Coronal brain sections were stained with immunohistochemical reaction to α-actin (1A4, Dako, Denmark). Brain of intact animals and contralateral hemisphere served as a control. In intact animals, small blood vessels (BV) with a narrow immunopositive rim are located along the SVZ. In some of BV, immunocytochemical reaction does not cover the entire perimeter of the vessel completely. In ischemic animals, in the affected hemisphere in the case of major damage, dilated BV were observed. In the subependymal area of SVZ, ramified immunopositive cells appear, with some of which being located close to the BV. Some of the cells with weak immunocytochemical reaction to actin are found near the border of ventricular cavity. There are some single branched actin-immunopositive cells. Thus, after ischemic brain damage associated with severe damage to neurons in the striatum, there is smooth muscle component reorganization in SVZ, which is expressed as an eviction of individual smooth muscle cells or pericytes differentiated into smooth muscle cells in subependimal area with the penetration of individual cells in the ependymal layer. The functional significance of the observed phenomenon is not clear and needs further exploration.