Vol. 34, N 4

Evaluation of changes in the locomotion and histology of sciatic nerve following experimental autoimmune encephalomyelitis

CHANG, S. M. W.; WAI, S. X.; CHIN, P. Y.; LIM, J. T.; MITRA, N. K.

KEYWORDS: experimental autoimmune encephalomyelitis, footprint analysis, histology, sciatic nerve, spinal cord.

ABSTRACT: Introduction: Involvement of peripheral nerves in the experimental model of multiple sclerosis (MS) is rarely observed. The objective of this study was to investigate the changes in the locomotion in a mouse model of experimental autoimmune encephalomyelitis (EAE) and correlate with histological changes, if any, in the sections of sciatic nerve and lumbar part of spinal cord. Material and Methods: C57BL/6 mice (10 weeks, n = 8) were immunized with single subcutaneous injection of 300 g of MOG35-55 and 200 L of complete Freunds adjuvant (CFA) to produce EAE models. Limp tail with weakness of hindlimb was observed on day 10 and improvement in the weakness was observed on day 20 onwards. Footprint analysis was done to evaluate the impairment in the locomotion on day 0, 5, 10, 15 and 20 of the experiment. Results: One way repeated measure ANOVA found significant reduction in the mean hindlimb stride length on day 10 and 15 (left) and on day 15 and day 20 (right) when compared to mean stride length in day 0 (p<0.05). Histological analysis showed evidence of macrophage infiltration around the dilated blood vessels in the epineurium of sciatic nerve and evidence of damage in the myelinated white matter of lateral funiculus of the lumbar sections of the spinal cord in EAE mice. Conclusion: It is concluded that in mouse model of EAE, the impairment of locomotion due to damage in the lumbar part of spinal cord can be associated with inflammatory changes in the sciatic nerve.