Electric shock causes a fear-like persistent behavioral response in the nematode Caenorhabditis elegans

Abstract

ABSTRACTElectricity is utilized as an environmental stimulus by many animal species. Despite its importance, however, molecular and physiological mechanisms for responding to electric stimuli are poorly understood compared to other sensory stimuli. Here we report novel behavioral responses to electric stimuli in the Caenorhabditis elegans. When the animals on food are stimulated by alternating current, their movement speed suddenly increases more than 2-fold, which persists for minutes even after the electric stimulation is terminated. Genetic analyses reveal that multiple types of voltage-gated channels are required for the response, possibly as the sensors, and neuropeptide signaling regulates the duration of persistent response. Additional behavioral analyses indicate that the animal’s response to electric shock is scalable and has a negative valence. These properties, along with persistence, have been recently regarded as essential features of emotion, suggesting that the animal’s response to electric shock may express a form of emotion, such as fear.