University of Louisville Research Foundation, Inc.
David S. K. Magnuson, Ph.D.

Spinal cord injury is a devastating occurrence that can have a variety of physiological effects depending on the severity and level of injury. The first few hours and days after the injury are termed the acute phase, and many events are occurring at this time. Severe inflammation develops and the spinal cord enters into a state of shock, termed spinal shock. During the first week after injury, monocytes, macrophages, neutrophils and T-lymphocytes invade the damaged region (Popovich et al.,1997) and begin to remove debris. However, the mere presence of these cells and the inflammatory molecules that they release can cause additional damage to the surrounding tissue. In addition to this occurrence, new blood vessels are forming (angiogenesis), which may be beneficial in supplying the injured cord with nutrients and oxygen (Loy et al., 2002). One of the major challenges in dealing with rehabilitation after spinal cord injury is determining the optimal time for initiating therapy. We originally believed that beginning swimming training as soon as possible after injury would be beneficial to the animals, and would result in improved walking and swimming scores. Surprisingly, we discovered that animals that began training 3 days after injury did poorly compared to animals that began training two weeks after injury. The goal of this project is to determine whether early exercise after moderate spinal cord injury at the thoracic level (T9) exacerbates blood vessel leakiness and alters the levels of inflammatory molecules in the spinal cord. The specific aims for this project are: 1). To assess vessel leakiness after early swim training following a moderate, thoracic spinal cord injury. 2). To determine the changes in microglia, macrophages, and T-lymphocytes for injured animals that begin swim training at either 3, 7 or 14 days after injury.