Abstract
Light-scattering signal, which is sensitive to cellular/subcellular structural integrity, is a potential
indicator of brain tissue viability, because metabolic energy is used in part to maintain the structure of
cells in the brain. First, we examined how light scattering changed during viability loss of the brain
without hemoglobins, for which diffuse reflectance measurements were performed for a rat global
ischemic brain model made by perfusing the whole blood. After oxygen/glucose deprivation, we
observed a unique triphasic scattering change (TSC), which almost coincided with cerebral ATP decrease
in the brain. Secondly, we showed that TSC can be detected even in the presence of blood by using NIR
light in a rat hypoxic brain model. The brain recovered when oxygen was restored during the TSC.
These results suggest the usefulness of light-scattering signals for monitoring brain tissue reversibility
after serious brain diseases and injuries including acute ischemic stroke and traumatic brain injury.
