Effects of ensheathing cells transplanted into photochemically damaged spinal cord

Transplantation of olfactory ensheathing cells (OECs) into photochemically damaged rat spinal cord diminished astrocyte reactivity and parenchyma cavi tation. The photochemical lesion performed at T12-L1 resulted in severe dam age to the spinal cord, so that during the first 15 days postoperation all rats dragged their hindlimbs and did not respond to pinprick. The maximal a rea and volume of the cystic cavities were lower in transplanted than in no n-transplanted rats, not significantly at the T12-L1 lesion site, but signi ficantly at T9-T10 and L4-L6 cord levels. The density of astrocytes in the grey matter was similar at T12-L1 and L4-L6 in non-transplanted and trans-p lanted rats, but lower in the latter at T9-T10 level. However, in non-trans planted rats all astrocytes showed a hypertrophied appearance, with long an d robust processes heavily GFAP-positive, and overexpression of proteoglyca n inhibitor of neuritogenesis, whereas in transplanted rats only a few astr ocytes showed hypertrophy and the majority had short, thin processes. These results indicate that OECs transplanted into damaged adult rat spinal cord exert a neuroprotective role by reducing astrocytic gliosis and cystic cav itation. NeuroReport 12:2303-2309 (C) 2001 Lippincott Williams & Wilkins.