Back to Search
Start Over
Differential fear conditioning generates prefrontal neural ensembles of safety signals.
- Source :
-
Behavioural brain research [Behav Brain Res] 2019 Mar 15; Vol. 360, pp. 169-184. Date of Electronic Publication: 2018 Nov 28. - Publication Year :
- 2019
-
Abstract
- Fear discrimination is critical for survival, while fear generalization is effective for avoiding dangerous situations. Overgeneralized fear is a typical symptom of anxiety disorders, including generalized anxiety disorder and posttraumatic stress disorder (PTSD). Previous research demonstrated that fear discrimination learning is mediated by prefrontal mechanisms. While the prelimbic (PL) and infralimbic (IL) subdivisions of the medial prefrontal cortex (mPFC) are recognized for their excitatory and inhibitory effects on the fear circuit, respectively, the mechanisms driving fear discrimination are unidentified. To obtain insight into the mechanisms underlying context-specific fear discrimination, we investigated prefrontal neuronal ensembles representing distinct experiences associated with learning to disambiguate between dangerous and similar, but not identical, harmless stimuli. Here, we show distinct quantitative activation differences in response to conditioned and generalized fear experiences, as well as modulation of the neuronal ensembles associated with successful acquisition of context-safety contingencies. These findings suggest that prefrontal neuronal ensembles patterns code functional context-danger and context-safety relationships. The PL subdivision of the mPFC monitors context-danger associations to conditioned fear, whereas differential conditioning sparks additional ensembles associated with the inhibition of generalized fear in both the PL and IL subdivisions of the mPFC. Our data suggest that fear discrimination learning is associated with the modulation of prefrontal subpopulations in a subregion- and experience-specific fashion, and the learning of appropriate responses to conditioned and initially generalized fear experiences is driven by gradual updating and rebalancing of the prefrontal memory representations.<br /> (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Subjects :
- AIDS-Related Complex genetics
AIDS-Related Complex metabolism
Analysis of Variance
Animals
Doxycycline pharmacology
Freezing Reaction, Cataleptic physiology
Gene Expression drug effects
Green Fluorescent Proteins genetics
Green Fluorescent Proteins metabolism
Histones genetics
Histones metabolism
Mice
Mice, Inbred C57BL
Mice, Transgenic
Phosphopyruvate Hydratase metabolism
Time Factors
Conditioning, Classical physiology
Discrimination, Psychological physiology
Fear physiology
Neurons physiology
Prefrontal Cortex cytology
Subjects
Details
- Language :
- English
- ISSN :
- 1872-7549
- Volume :
- 360
- Database :
- MEDLINE
- Journal :
- Behavioural brain research
- Publication Type :
- Academic Journal
- Accession number :
- 30502356
- Full Text :
- https://doi.org/10.1016/j.bbr.2018.11.042