Figure 1.

Immune response following SCI. Trauma to the spinal cord elicits an immune response, which begins almost immediately after injury. Neutrophils are the first immune cells to respond to the lesion site, arriving within the first few hours after injury, and remaining for up to 3 days after injury. Vascular macrophages are the second class of immune cell to arrive at the lesion, arriving after the initial infiltration of neutrophils. Activation and infiltration of vascular macrophages subsequently activate and recruit microglial cells, which can persist in the lesion site for months after injury [4–7].