An update on contextual fear memory mechanisms: Transition between Amygdala and Hippocampus. (September 2018)

• Record Type: Journal Article
• Authors: Chaaya, Nicholas; Battle, Andrew R.; Johnson, Luke R.
• Is Part Of: Neuroscience and biobehavioral reviews. Volume 92(2018)
• Page Start: 43
• Page End: 54
• Publication Date: 2018-09
• Subjects: Contextual fear conditioning -- Amygdala -- Hippocampus -- Memory consolidation -- Memory maintenance; Psychophysiology -- Periodicals; Human behavior -- Periodicals; Animal behavior -- Periodicals; Neurology -- Periodicals; Behavior -- Periodicals; Ethology -- Periodicals; Neurology -- Periodicals; Psychophysiologie -- Périodiques; Comportement humain -- Périodiques; Animaux -- Mœurs et comportement -- Périodiques; Neurologie -- Périodiques; Animal behavior; Human behavior; Neurology; Psychophysiology; Periodicals; Electronic journals; 573.8
• DOI: 10.1016/j.neubiorev.2018.05.013
• Languages: English
• ISSNs: 0149-7634

Abstract

Highlights: Contextual fear memories undergo consolidation in both amygdala and hippocampus. The hippocampus maintains contextual fear memories. The amygdala may also maintain contextual fear memories. Abstract: Context is an ever-present combination of discrete environmental elements capable of influencing many psychological processes. When context is associated with an aversive stimulus, a permanent contextual fear memory is formed. Context is hypothesized to greatly influence the treatability of various fear-based pathologies, in particular, post-traumatic stress disorder (PTSD). In order to understand how contextual fear memories are encoded and impact underlying fear pathology, delineation of the underlying neural circuitry of contextual fear memory consolidation and maintenance is essential. Past understandings of contextual fear suggest that the hippocampus only creates a unitary, or single, representation of context. This representation is sent to the amygdala, which creates the associative contextual fear memory. In contrast, here we review new evidence from the literature showing contextual fear memories to be consolidated and maintained by both amygdala and hippocampus. Based on this evidence, we revise the current model of contextual fear memory consolidation, highlighting a larger role for hippocampus. This new model may better explain the role of the hippocampus in PTSD.