Attempts to Transmit Poliomyelitis to Mice,Rats,Guinea Pigs and Rabbits. ∗

Abstract

The successful transmission of poliomyelitis to the commoner and cheaper laboratory animals would be of inestimable assistance to investigations upon infection, immunity and specific therapy of this disease. Since Flexner and Lewis 1 recorded the failure of dinitrophenol (hereinafter called αDNP) increases the rate of goats, pigs, sheep, rats, mice, dogs and cats, various other investigators have attempted transmission to the lower animals but with uniform failure except in the case of monkeys and apes.

Now that it is known that syphilis may be transmitted to mice, rats and guinea pigs and that Spirochaeta pallida may survive in the lymph glands, brain (especially of mice) and other organs for long periods of time without any clinical signs or symptoms of the disease, we have sought to transmit the virus of poliomyelitis to mice, rats, guinea pigs and rabbits by injecting them intracerebrally with 0.1 to 0.2 cc. of 10% emulsions of monkey poliomyelitic spinal cord.

Four animals of each group were inoculated under ether anesthesia and after an interval of 3 weeks, during which time the 16 animals were carefully observed for any possible signs of infection, all were chloroformed and the brains removed. A 10% emulsion of the anterior lobes of the cerebrums of the 4 mice was prepared and injected intracerebrally into 4 fresh mice, the emulsions being prepared from the sites of the former injection. Similar emulsions were prepared of the inoculated sites of the brains of the 4 rats and inoculated into 4 fresh rats; similar emulsions were prepared of the guinea pig and rabbit brains and likewise inoculated into 4 fresh guinea pigs and rabbits respectively. After 3 weeks of observation this procedure was repeated a third time and finally a fourth time before the experiments were terminated.