The extinction of delay fear conditioning relies on a neural circuit that has received much attention and is relatively well defined. Whether this established circuit also supports the extinction of more complex associations, however, is unclear. Trace fear conditioning is a better model of complex relational learning, yet the circuit that supports extinction of this memory has received very li...

In rodents, the infralimbic (IL) region of the medial prefrontal cortex plays a key role in the recall of fear extinction. Previously we showed that fear conditioning decreases the intrinsic excitability of IL neurons, and that fear extinction reverses the depressed excitability. In the current study, we examined the time course of the extinction-induced changes in adolescent rats. Immediately ...

Uncertainty of fear conditioning is crucial for the acquisition and extinction of fear memory. Fear memory acquired through partial pairings of a conditioned stimulus (CS) and an unconditioned stimulus (US) is more resistant to extinction than that acquired through full pairings; this effect is known as the partial reinforcement extinction effect (PREE). Although the PREE has been explained by ...

Growing evidence indicates that the activity of infralimbic prefrontal cortex (IL) is critical for inhibiting inappropriate fear responses following extinction learning. Recently, we showed that fear conditioning and extinction alter the intrinsic excitability and bursting of IL pyramidal neurons in brain slices. IL neurons from Sprague Dawley rats expressing high fear had lower intrinsic excit...

It has been more than a decade since Ressler et al. published the first demonstration of facilitation of exposure-based therapy with the N-methyl-D-aspartate co-agonist D-cycloserine (1). Since that pivotal study, there has been a surge of research to identify additional targets that enhance fear extinction for adjunctive treatment strategies. Potential pathways include catecholamines, endocann...

Fear extinction is impaired in neuropsychiatric disorders, including posttraumatic stress disorder. Identifying drugs that facilitate fear extinction in animal models provides leads for novel pharmacological treatments for these disorders. Zinc (Zn) is expressed in neurons in a cortico-amygdala circuit mediating fear extinction, and modulates neurotransmitter systems regulating extinction. We p...

The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h after fear conditioning. Upon presentation of unsi...

Extinction-resistant fear is considered to be a central feature of pathological anxiety. Here we sought to determine if individual differences in Intolerance of Uncertainty (IU), a potential risk factor for anxiety disorders, underlies compromised fear extinction. We tested this hypothesis by recording electrodermal activity in 38 healthy participants during fear acquisition and extinction. We ...

BACKGROUND Previous work has implicated noradrenergic beta-receptors in the consolidation and reconsolidation of conditioned fear. Less is known, however, about their role in fear expression and extinction. The beta-receptor blocker propranolol has been used clinically to reduce anxiety. With an auditory fear conditioning task in rats, we assessed the effects of systemic propranolol on the expr...

Attentional control (AC) and fear extinction learning are known to be involved in pathological anxiety. In this study we explored whether individual differences in non-emotional AC were associated with individual differences in the magnitude and gradient of fear extinction (learning and recall). In 50 individuals with fear of spiders, we collected measures of non-emotional AC by means of self-r...