Allergic Encephalomyelitis in the Rat Induced by the Intracutaneous Injection of Central Nervous System Tissue and Adjuvants

Abstract

Allergic meningo-encephalomyelitis can be induced in the white rat by the intracutaneous injection of a suspension of brain or spinal cord combined with paraffin oil and killed mycobacteria. Constant symptoms are flaccid paralysis of the hind legs, urinary incontinence and fecal impaction. Remissions are frequent. Constant lesions are mild, focal, mononuclear meningitis, mononuclear cuffing of venules and capillaries of the brain and spinal cord. Glial nodules may occur. Compared on the basis of weight, spinal cord from the rat or guinea pig is about equally effective; rat brain and rabbit spinal cord are less effective. The presence of killed mycobacteria or Nocardia asteroides in the emulsion is essential for the production of the experimental disease. The intracutaneous injection of a suspension of 120 mg rat spinal cord and adjuvants induced encephalitis regularly, whereas the subcutaneous injection of the same material was without effect. Rat spinal cord combined with adjuvants injected intracutaneously causes encephalitis in the guinea pig.