Up-regulation of glial cell line-derived neurotrophic factor (GDNF) following traumatic spinal cord injury

We investigated the temporal and spatial expression patterns of the GDNF ge ne after subjecting rats to an acute contusion injury of the spinal cord us ing the weight drop technique. Reverse transcriptase-polymerase chain react ion (RT-PCR) revealed that GDNF transcription in the spinal cord began to i ncrease within 30 min after injury and peaked within 3 h. Immunohistochemic al analysis showed GDNF immunoreactivity to be present mainly in microglia and macrophages 1 day after injury,but not in neurons or astrocytes. This i mmediate upregulation of GDNF gene expression may be a component of an infl ammatory process and probably exerts a protective effect on neurons followi ng spinal cord injury (SCI). NeuroReport 11:3877-3881 (C) 2000 Lippincott W illiams & Wilkins.