Expression of myelin basic protein (MBP) after colchicine injection into the sciatic nerve

J.B. AQUINO; M.F. CORONEL; J.M. PASQUINI; E.F. SOTO; C.P. SETTON-AVRUJ; M.J. VILLAR

San Diego, USA

Congreso; Society for Neuroscience; 2001

Society for Neuroscience

Peripheral nerve ligation and crush alter the normal pattern of expression of MBP during Wallerian degeneration with the appearance of clusters of the protein distally to the injury. In this study we have further analyzed these changes after blocking the axonal transport in sciatic nerve fibers. Animals were anaesthetized and their right sciatic nerves exposed at the level of the thigh and injected with 1 m l of colchicine (5 and 10 mM). Sham animals with injection of saline into the sciatic nerve were also prepared. Animals were allowed to survive for 3-7 days and perfused. The ipsilateral and contralateral sciatic nerves were dissected out and processed for immunohistochemistry using MBP antibodies. The results showed a normal pattern of MBP-like immunoreactivity (LI) in the sciatic nerve of sham operated animals as well as in the contralateral nerves of colchicine-injected rats. The sciatic nerves injected with colchicine showed a pattern of MBP-LI that resembled that previously observed after peripheral nerve injury. Preliminary experiments where colchicine was injected in parallel with nerve growth factor showed a marked decrease in the number of clusters as compared to colchicine injected rats. These results support the idea that the normal expression of MBP in Schwann cells may be dependent on nerve growth factor.