Spinal cord injury results in dramatic changes in the neurochemistry of peripheral and central micturition reflex pathways. We studied an animal model of spinal cord contusion injury using Sprague Dawley rats. Recoveries of motor and bladder functions were recorded, along with the changes in brain-derived neurotrophic factor (BDNF) in regions rostral and caudal to the injury site. Results are as follows: 1. Motor functions examined by the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale were fully recovered 28 d after spinal cord injury. 2. Bladder functions, monitored urodynamically, changed from flaccid paralysis at 4 d after spinal cord injury to spastic paralysis at 14, 18, and 28 d. 3. BDNF immunoreactive neurons and glial cells were found in both gray and white matters of the normal spinal cord, and the numbers decreased gradually after spinal cord injury 4. BDNF enzyme linked immunosorbent assay (ELISA) results were almost the same as for immunohistochemistry, but the intensity of decrease was more prominent in the caudal than in the rostral regions. Distinguishing between the beneficial or detrimental effects of neurotrophic factors in the context of micturition reflexes or regenerative responses will be a challenge, but is essential to understanding the effects of therapies directed at blocking the effects of neuroactive compounds or neurotrophic factors.