Cardiac pulse transfer along the cerebral microvascular network captured by laser speckle contrast imaging

Detecting subtle alterations in cardiac pulse transmission through the cerebral microvascular network could provide a new avenue for characterising cerebral microvascular health and aid in the research and diagnosis of related neurological pathologies. We used laser speckle contrast imaging to quantify the pulse waveform in cerebral microvasculature in awake and anaesthetised mice. Pulse amplitude was attenuated more efficiently in awake mice, with venular pulsatility index 63% lower than arterial, compared to a 9% and 30% reduction under isoflurane and ketamine-xylazine, respectively. Arterial-to-venous delay was similar when awake and under isoflurane (5.3±1.6 and 5.4±1 ms) but longer under ketamine-xylazine (10.3±1.7 ms).