Herpes simplex virus type I (HSV-I) is a latent neuroinfection which can cause focal brain lesion. The role of HSV-infection in nerve regeneration has not been studied so far. The aim of the work was to study sciatic nerve regeneration in the presence of HSV-infection and the influence of an antiviral drug. BALB/c line mice were divided into five groups. Group 1 animals were infected with HSV-I. After resolution of neuroinfection manifestations the sciatic nerve of these animals was crushed. Group 2 mice were administered acyclovir following the same procedures. Groups 3-5 mice served as controls. Thirty days after the operation distal nerve stumps and m.gastrocnemius were studied morphologically and biochemically. Ultrastructural organization of the sciatic nerve in control animals remained intact. Morphometric parameters of the nerves from the experimental groups have not reach control values. However, in the group 1 diameter of nerve fibers was significantly smaller than in the group 2. Both nerve regeneration and m.gastrocnemius reinnervation were confirmed. The muscle hypotrophy was found in groups 1, 2, and 3 (the muscle fibers diameter decreased). Metabolic changes in the muscles of the infected animals (groups 1 and 2) were more pronounced than in control groups 3 and 4. The levels of TBA-active products, conjugated dienes, carbonyl and SH-groups were reduced in m.gastrocnemius of the experimental groups, however no significant difference associated with acyclovir administration was found. HSV-infection is not limited to the local neurodegenerative changes in the CNS but affects regeneration of the injured sciatic nerve. Anat Rec, 301:1734-1744, 2018. © 2018 Wiley Periodicals, Inc.

To investigate reactive changes of GFAP-positive astrocytes as a marker of brain response following hemorrhagic stroke and HSV-I. Methods. The experiments were performed on 110 Balb/c mice weighing 18-20 g. The animals were infected with HSV type I, on 30 day hemorrhagic stroke was simulated and changes in astrocytes were determined by immunohistochemistry. Gliosis was confirmed by changes in density and arborization of GFAP-positive astrocytes. Results. The results of immunohistochemical studies confirmed increased density of GFAP-positive astrocytes in the hippocampus of mice infected with HSV type I as well as the sharp increase in the density and hypertrophy of GFAP-positive astrocytes following stroke simulation in infected animals. Conclusions. The experiment has provided new evidence about the location and level of astrocytic gliosis following a stroke and herpes infection. GFAP can be studied as a marker of HSV type I reactivation against stroke.