Abstract
Measurement of local blood flow by hydrogen clearance is a useful technique and is compatible with simultaneous measurement of oxygen tension over long periods. However, existing methods present serious limitations of spatial resolution due to high diffusion rates and other factors. Improved methods permit local measurements in both gray and white matter of the rat spinal cord that correlate well with data from autoradiographic techniques, and indeed distinguish between individual gray matter laminae. Applications of similar methods should be useful in other systems where high spatial resolution is required.