ALTERATION OF E-CADHERIN AND ALPHA-N-CATENIN IMMUNOREACTIVITY IN THE MOUSE SPINAL-CORD FOLLOWING PERIPHERAL AXOTOMY

We examined the effects of peripheral axotomy on the immunoreactivity of E-cadherin and cadherin-associated protein alpha N-catenin in the s pinal cord. E-cadherin is known to be exclusively expressed in lamina II of Rexed in the spinal cord dorsal horn. This expression disappeare d by day 7 after axotomy and reappeared following nerve ligature (part ial axonal regeneration model) on day 63. In contrast, it remained und etectable following nerve clipping (complete degeneration model). Alph a N-catenin was diffusely stained in the gray matter, and the immunore activity was specifically intense in the central canal and superficial dorsal horn. The expression of alpha N-catenin in the superficial dor sal horn was similarly reduced by day 7 after axotomy, but recovered b y day 63 after nerve ligature. In contrast, it remained at the reduced level after nerve clipping. The alteration of alpha N-catenin immunor eactivity showed a similar pattern consistent with that of E-cadherin. Administration of nerve growth factor (NGF) rescued the immunoreactiv ity of substance P, which is known to disappear after peripheral axoto my, but not influence that of both E-cadherin or alpha N-catenin. Thes e results clearly showed that peripheral axotomy simultaneously alters the immunoreactivity of E-cadherin and alpha N-catenin in the spinal cord, suggesting a correlation in the expression of both E-cadherin an d alpha N-catenin in vivo. E-cadherin-alpha N-catenin complex might be crucial for plasticity of the spinal cord dorsal horn after periphera l axotomy.