Regulating fear memory

Abstract

Neuroscience Treatment for anxiety and fear is often based on extinction training, but fear can spontaneously reappear even after successful initial treatment. Neuroscientists have discovered two different neuronal ensembles operating within the brain's hippocampal dentate gyrus: extinction neurons and fear engram neurons. Lacagnina et al. used optogenetics and neural tagging to identify, stimulate, and inhibit these different neuronal populations. They found that silencing fear engram neurons prevented spontaneous fear recovery, whereas silencing extinction neurons impaired the trained memory that suppresses fear (extinction retrieval). By contrast, stimulating fear engram neurons potentiated fear, whereas stimulating extinction neurons suppressed it. Nat. Neurosci. 22 , 753 (2019).