Figure 1.

Computer monitor captures of raw data of 2 D scans of the guinea pig spinal cord. A is prior to Injury, and B is the same cord after crush of the tissue with a laboratory fabricated forceps possessing a détente. Vectors (as arrows) reveal inwardly directed current entering at peak magnitude at the locus of the crush injury and declining in magnitude with distance from this site. Measurements were made approximately 15 mins post injury. The current was balanced by extracellular current measured entering the tissue in relatively undamaged regions of white matter bordering the injury zone. Pre-injury current along uninjured spinal cords was no different than background (arrowheads in A). The background current was offset by taking a reference measurement before actual injury currents were measured.