ACUTE DISPERSION OF GLIAL-CELLS FOLLOWING TRANSPLANTATION INTO THE MYELIN-DEFICIENT RAT SPINAL-CORD

Evaluation of glial cell migration following transplantation can be di fficult as the force of the injection itself may cause the cells to be come immediately dispersed. In this study we evaluated the extent of s pread of cells after injection of 1 mu l of a dissociated cell suspens ion (50,000 cells/mu l) into the dorsal columns of the thoracolumbar s pinal cord in the neonatal myelin-deficient (md) rat. Spinal cords wer e examined at 0, 4, and 24 h after injection to determine the dispersi on of cells away from the initial site of deposition. Examination of s kip-serial sections collected at 50-mu m intervals rostral and caudal to the site of transplantation showed that the injection could result in a spread of transplanted cells up to 1,600 mu m. Migration should t herefore be defined as the detection of cells beyond the rostral-cauda l boundaries defined by the injection deposition. Cell dispersion shou ld be taken into account when evaluating the results of migration in p revious and future experiments concerning glial cell transplantation. (C) 1995 Wiley-Liss, Inc.