Histopathology of Central Nervous System of Mice Inoculated with Poliomyelitis Virus

Abstract

Harmon, Shaughnessy and Gordon 1 reviewed the contradictory results of former authors in inoculating rodents with the virus of poliomyelitis. They reported that after intraperitoneal or intracranial injection of the virus into mice the majority of them died sporadic deaths. The autopsy revealed gross lesions of lung consolidation, “but no microscopic sections were prepared from the tissues of mice”.

The brain and spinal cords of 12 mice which had been injected with poliomyelitis virus by Dr. Nungester 2 together with those of 7 controls were cut serially and longitudinally and stained with cresylviolet. Four of the inoculated mice did not show any inflammation of the central nervous system. In 3 others mild inflammatory reactions in isolated segments of the dorsal and lumbar spinal cord were found in the form of perivascular leucocytic infiltration of one or 2 rows of cells and of a mild meningitis at the posterior surface in one case. In 3 other mice the leucocytic infiltration had spread into the posterior and anterior gray and was combined with hemorrhage into the anterior horns, mild increase in glia nuclei and meningitis along the spinal nerve roots. In 2 mice which had been injected with virus after passage through 3 generations of mice and which had developed weakness of the hind legs a poliomyelitis was found which resembled more closely the histo-pathology found in poliomyelitis of macacus, though the inflammation was localized to a few segments only. There was a marked perivascular infiltration of polymorphonuclear and small mononuclear round cells around the central vessels, spreading diffusely into the gray matter and accompanied by hemorrhage into the anterior horns (Figs. 1 and 2).