Lack of histological signs in rats dying during the acute phase of experimental auto-immune encephalomyelitis.

Rats dying acutely of experimental auto-immune encephalomyelitis show very meagre histological signs of the disease in routine histology sections. This cannot be explained by postmortal changes. It is suggested that the infiltrating lymphoid cells seen in the central nervous system for surviving rats are involved in the normally occurring self-limitation of the disease.