title: The neural circuits of innate fear: detection, integration, action, and memorization.
abstract: How fear is represented in the brain has generated a lot of research attention, not only because fear increases the chances for survival when appropriately expressed but also because it can lead to anxiety and stress-related disorders when inadequately processed. In this review, we summarize recent progress in the understanding of the neural circuits processing innate fear in rodents. We propose that these circuits are contained within three main functional units in the brain: a detection unit, responsible for gathering sensory information signaling the presence of a threat; an integration unit, responsible for incorporating the various sensory information and recruiting downstream effectors; and an output unit, in charge of initiating appropriate bodily and behavioral responses to the threatful stimulus. In parallel, the experience of innate fear also instructs a learning process leading to the memorization of the fearful event. Interestingly, while the detection, integration, and output units processing acute fear responses to different threats tend to be harbored in distinct brain circuits, memory encoding of these threats seems to rely on a shared learning system.
authors.affiliation: Laboratory of Neuroepigenetics, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Bianca A
authors.initials: BA
authors.lastname: Silva
authors.affiliation: Mouse Biology Unit, European Molecular Biology Laboratory (EMBL), 00015 Monterotondo, Italy.
authors.forename: Cornelius T
authors.initials: CT
authors.lastname: Gross
authors.affiliation: Laboratory of Neuroepigenetics, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale Lausanne, CH-1015 Lausanne, Switzerland johannes.graeff@epfl.ch.
authors.forename: Johannes
authors.initials: J
authors.lastname: Gräff
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D006801:Humans; D008568:Memory / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D012377:Rodentia