Dehydration and food deprivation exacerbate mouse cerebral microvascular responses to local hyperthermia

1. 1. Effects of 1-day deprivation from water, food or both on responses of mice pial microvessels to local cerebral hyperthermia were compared to fed mice and with access to water. 2. 2. A set of protocol for all groups was followed, which involved microsurgery and utilized intravital videomicroscopy. Core body temperature was kept at 37°C and hyperthermic exposure was applied locally by heating the artificial cerebrospinal fluid irrigating the brain surface, at 45°C for 25 min. 3. 3. Monitored responses included intravascular thrombo-embolic events and changes in microvascular diameter. Dehydration and food deprivation shortened the time for appearance of passing emboli and lowered the thermal threshold at which thrombo-embolic processes occur. 4. 4. Arteriolar constriction was observed in all groups, coupled with full occlusion. 5. 5. Data of this study revealed that dehydration and food deprivation exacerbate pial microcirculatory responses to local hyperthermia.