Cryo-jet preservation of calcium in the rat spinal cord.

In order to determine the distribution of diffusible ions, especially calcium, in rat spinal cord axons before and after trauma, sham, 6 hours post 6 gm/cm and 20 gm/cm trauma cords were cryo-jet frozen in situ and cryo-sections were subjected to electron probe X-ray microanalysis. The results confirm part of the Ca hypothesis, i.e., some spinal cord axons accumulate intracellular Ca after traumatic injury. In addition, 6 hours after trauma, Ca is only accumulated by axons that have also lost homeostasis. Thus, it is likely that observations of the continual rise of Ca in the traumatized spinal cord are due to an increase in the number of axons that have lost homeostasis rather than an overall increase in Ca within surviving cells.