Sustained hyperarousal induced by acute stress in tryptophan-hydroxylase-2 genetic deficient male mice

Abstract

Severe stress stimulation will cause persistent hyperarousal state, which is the core symptom of various stress disorders and pro-motes the occurrence and development of other symptoms. This study focused on the role of 5-hydroxytryptamine in the occurrence and development of stress-induced hyperarousal. By measuring the auditory startle reflex level to reflect the state of hyperarousal, we investigated the changes of hyperarousal in tryptophan hydroxylase-2 gene deficient mice before and after predator exposure or elec-tric footshock stress. Studies have found that male genetically deficient mice showed hyperarousal performance lasting for more than one week after stress, while wild-type mice showed a hyperarousal state that recovered quickly. The results suggest that the decrease of serotonin caused by gene deficiency may be a susceptible factor of persistent hyperarousal induced by severe stress.