Neural Circuits Mediating Fear Learning and Extinction.

The activity of neural circuits that underpin particular behaviours are one of the most interesting questions in neurobiology today. This understanding will not only lead to a detailed understanding of learning and memory formation, but also provides a platform for the development of novel therapeutic approaches to a range of neurological disorders that afflict humans. Among the different behavioural paradigms, Pavlovian fear conditioning and its extinction are two of the most extensively used to study acquisition, consolidation and retrieval of fear-related memories. The amygdala, medial prefrontal cortex (mPFC) and hippocampus are three regions with extensive bidirectional connections, and play key roles in fear processing. In this chapter, we summarise our current understanding of the structure and physiological role of these three regions in fear learning and extinction.