Methods for evaluating changes in permeability of the blood-brain barrier and liquor-blood barrier in experimental tick-borne encephalitis

Abstract

Studying the interaction of neurotropic viruses with BBB structures is the most interesting and understudied subject. Viruses greatly differ in the nature of this interaction and use various mechanisms to overcome the BBB on the path to the central nervous system (CNS). Viruses affect permeability of the BBB directly or indirectly. Changes in permeability of the blood-cerebrospinal fluid barrier (BCB) have not been studied in viral infection. The aim of this study was to assess the informative value of methods for determination of changes in BBB and BCB permeability. Methods. Using intraperitoneal (i/p) and intraspinal (i/sp) sodium fluorescein injections changes in BBB and BCB permeability were measured by the ratio of cerebral or spinal cord homogenate fluorescence to serum fluorescence in mice infected with two strains of tick-borne encephalitis virus. Results. This study found both increased BBB permeability and decreased dye penetration from blood into the CNS following the i/p dye injection and into the blood following the i/sp dye injection in viral infection. This can be explained by the circulatory collapse and fatal injuries of the CNS typical for tick-borne encephalitis. Conclusion. Using different methods of dye injection provides a comprehensive assessment of cerebral circulatory disorders in viral infection in addition to information about changes in BBB and BCB permeability.