Time-related ex vivo changes in the optical properties of normal brain tissues

The aim of the study was to observe time-related changes in the optical properties of normal brain tissues as measured using cross-polarization optical coherence tomography (CP OCT). 32 ex vivo tissue samples from 16 animals (rats) were monitored under different external conditions, over a period of 1 hour after excision, to measure time-related optical changes. It was found that the optical properties of white matter were quite stable over the time scales of the experiments, while the optical properties of the gray matter could change significantly. However, these changes could be minimized by using fresh sections from samples that had not been in contact with the air or the saline solution before the CP OCT examination. Such a protocol is suggested to significantly reduce optical changes in the brain tissue samples when ex vivo study is needed.