The Mechanism of Fear at Behavior, Brain Circuits and Molecular Level

The study of “fear” can be traced back to the differences between “behaviorism” and “psychoanalysis” on cognition, while recent research on the learning and memory of fear by using modern cell and molecular biology experimental techniques has made our understanding of “fear” gradually multi-level and in-depth. At present, our research on fear can be divided into three levels, namely behavior, brain circuits and molecular. At the level of behavior, Pavlovian conditioning experiments have become the core method for studying fear, and behavioral approaches have been used for fear-related mental illnesses, such as the treatment of Post-Traumatic Stress Disorder (PTSD). At the level of brain circuits, the brain circuits with the amygdala as the core have gradually become clear, and there is also a two-system or one-system debate on how to recognize the fear process. At the molecular level, the Hebbian synaptic plasticity mechanism and neuromodulatory-dependent mechanism are used to explain the process of fear memory acquisition. Based on the current three levels of research, revealing how feelings of fear may generate is likely to play a guiding role in the further understanding of “fear” and treatment of related diseases