Mechanisms of fear extinction

refrontal Mechanisms in Extinction f Conditioned Fear

nterest in the medial prefrontal cortex (mPFC) as a source of behavioral inhibition has increased with the mounting evidence for a unctional role of the mPFC in extinction of conditioned fear. In fear extinction, a tone-conditioned stimulus (CS) previously paired ith a footshock is presented repeatedly in the absence of footshock, causing fear responses to diminish. Here, we review converging v...

Amount of fear extinction changes its underlying mechanisms

There has been a longstanding debate on whether original fear memory is inhibited or erased after extinction. One possibility that reconciles this uncertainty is that the inhibition and erasure mechanisms are engaged in different phases (early or late) of extinction. In this study, using single-session extinction training and its repetition (multiple-session extinction training), we investigate...

Extinction of Recent Fear: Behavioral and Neural Mechanisms

Different mechanisms of fear extinction dependent on length of time since fear acquisition.

Fear extinction is defined as a decline in conditioned fear responses (CRs) following nonreinforced exposure to a feared conditioned stimulus (CS). Behavioral evidence indicates that extinction is a form of inhibitory learning: Extinguished fear responses reappear with the passage of time (spontaneous recovery), a shift of context (renewal), and unsignaled presentations of the unconditioned sti...

Fear extinction in rodents.

Pavlovian conditioning paradigms have become important model systems for understanding the neuroscience of behavior. In particular, studies of the extinction of Pavlovian fear responses are yielding important information about the neural substrates of anxiety disorders, such as phobias and post-traumatic stress disorder (PTSD) in humans. These studies are germane to understanding the neural mec...