Histological study of the cerebral cortex and spinal cord in a model of experimentally induced autoimmune encephalomyelitis in adult albino rabbits

ABSTRACT

Axonal damage is responsible for the increasing disability seen in patients afflicted with multiple sclerosis [MS]. An animal model of autoimmune encephalomyelitis may help to develop better therapeutic and neuroprotective strategies. The aim of the study was to investigate the histological patterns of axonal injury and the mechanism of demyelination in autoimmune encephalomyelitis in the cerebral cortex and spinal cord of adult albino rabbits. Twenty male adult albino rabbits were divided into two groups the control group - group I [10 animals] - and the experimental group - group II [10 animals]. Autoimmune encephalomyelitis was induced by the injection of 0.3 ml/kg of 0.01% ethidium bromide solution. The animals were sacrificed and their cerebral cortex and spinal cord were processed for light microscopic examination, whereas electron microscopy was used to study the lumbar segment of spinal cord. Light microscopic examination of the cerebral cortex and spinal cord showed some cellular infiltration, together with degeneration and necrosis of nerve cells. Electron microscopic examination of the white matter of the spinal cord showed areas of destruction of nerve fibers, together with defective myelination. The extent of motor neuron inflammation and demyelination, axonal damage, and white matter pathology are reflective of the severity of experimental MS. Our results delineate the experimental autoimmune encephalomyelitis model as a valuable tool for MS research