Chinese medicine thinks kidney stores essence and the emotion related to the kidney is fear. Kidney essence is the material foundation and fundamental guarantee of kidney regulating emotions. When the body is under panic stress

lack of kidney essence could facilitate fear memory formation and consolidate fear memory which is made difficult to fade. Consolidation of fear memory could make patients under the state of being chronically fearful or extremely fearful

which could consume kidney essence further. Prefrontal cortex-amygdala-hippocampus is a neural circuit that is closely related to the formation and extinction of fear memory. Prescription and herbs of invigorating the kidney have significant regulating effect on the formation and extinction of fear memory. Based on these

the authors put forward a scientific hypothesis that " Taking prefrontal cortex-amygdala-hippocampus as the action pathway

the kidney essence may show the overall regulation of the interaction between hormone and transmitter systems to play its effect of tranquilizing the mind and promoting fear extinction by influencing synthesis

release and expression of stress hormones（ neuropeptides） and neurotransmitters and their receptors closely related to fear memory ". The authors make preliminary discussion about future research ideas from the aspects of animal model

hormones-neurotransmitters and epigenetics mechanism.