Laser speckle imaging of the hippocampus.

Research on hippocampal blood flow is essential for gaining insight into its involvement in learning and memory and its role in age-related cognitive impairment and dementia. In this study, we applied laser speckle contrast imaging (LSCI) and dynamic light scattering imaging (DLSI) to monitor perfusion in mouse hippocampus via a chronic, optically transparent window. LSCI scans showed hippocampal blood vessels appear more out of focus than similar caliber vessels in the mouse cortex. We hypothesize that it is caused by the inverse vascular topology and increased contribution of multiply-scattered photons detected from the upper layers of the hippocampus. We support the hypothesis with DLSI, showing a 1300% increased contribution of multiple-scattering unordered dynamics regime in large hippocampal vessels.