The effect of earthing mat on stress-induced anxiety-like behavior and neuroendocrine changes in the rat.

Park et al, 2022 [pre-clinical study, Sprague–Dawley rats, male, 6–7 weeks old] aimed to investigate whether grounding in the rats could change stress-related anxiety and depressive behaviors and the production of corticotrophin-releasing factors in the brain region. Immobilization stress model was performed 2 h per day for 21 consecutive days. For 7 days (A7) or 21 days (A21) groups, they received immobilization stress for 21 consecutive days and were placed in cage with earthing mattress. Neither immobilization stress nor earthing mat was applied to the normal group. The earthing mat system consists of cotton sheet, and an electric emission plate connected to a ground port of an electrical outlet. Rats were placed on the earthing mat before behavioral tests. The depressive-and anxiety like behaviors were measured by forced swimming test (FST), tail suspension test (TST) and elevated plus maze (EPM). Using immunohistochemistry, the expression of corticotrophinreleasing factor (CRF) and c-Fos immunoreactivity were analyzed in the brain. Authors concluded that in the EPM, time spent in the open arm of the earthing mat groups was significantly increased compared to the Control group (p < 0.001), even though there were no effects among groups in the FST and TST. The expression of CRF immunoreactive neurons in the earthing mat group was markedly decreased compared to the Control group. Overall, the earthing mat reduced stress-induced behavioral changes and expression of c-Fos and CRF immunoreactivity in the brain. These results suggest that the earthing mat may have the potential to improve stressrelated responses via the regulation of the corticotrophinergic system.