Heat acclimation prevents neurobehavioral and physiological disorders in mice exposed to chronic aircraft noise

We aimed to test whether heat acclimation (HA) would protect against aircraft noise (AN)-induced neurobehavioral and physiological disorders in mice. A total of 90 adult male mice were equally divided into three groups: control (c) plus non-AN group, c plus AN group, and HA plus AN group. Neurobehavioral performances included passive avoidance tasks (to assess learning and memory function), Y-maze tests (to assess spatial memory ability), and novel object recognition tests. Physiological functions included stress responses, inflammation, and oxidative stress, which were determined biochemically. The severity of endotoxemia was determined by measuring the serum levels of lipopolysaccharide. Both gut barrier and blood-brain barrier permeability were determined by fluorescein isothiocyanate and Evans Blue dye measurement, respectively. Compared to c+non-AN mice, the c+AN mice displayed neurobehavioral disorders along with exacerbated stress reactions, gut barrier disruption, endotoxemia, blood-brain barrier disruption, and hippocampal inflammation and oxidative stress. Compared to c+AN mice, the HA+AN mice had significantly less severity of all the abovementioned behavioral and physiological impairments. These results suggest that HA counteracts neurobehavioral and physiological disorders in mice exposed to aircraft noise.