Reconsolidation is a post-retrieval process of restabilization of the memory trace. Previous findings from our group suggest that cortisol, a glucocorticoid hormone secreted in response to stress, enhances the reconsolidation of fear memories in healthy men. Cortisol effect was found to be very specific, enhancing only the fear memory that was reactivated (i.e. retrieved), but not the non-react...

The present study investigated the singular and joint effects of fear of somatic sensations and perceived safety of hypocapnia-induced bodily cues on nonclinical subjects' subjective and psychophysiological response to a hyperventilation challenge. Fear of fear was assessed with the Body Sensations Questionnaire (BSQ; High versus Low), and subjects were randomly assigned to one of two informati...

Cyclic AMP response element binding protein (CREB) plays a critical role in fear memory formation. Here we determined the role of CREB selectively within the amygdala in reconsolidation and extinction of auditory fear. Viral overexpression of the inducible cAMP early repressor (ICER) or the dominant-negative mCREB, specifically within the lateral amygdala disrupted reconsolidation of auditory f...

Fear conditioning, in which a cue is conditioned to elicit a fear response, and extinction, in which a previously conditioned cue no longer elicits a fear response, depend on neural plasticity occurring within the amygdala. Projection neurons in the basolateral amygdala (BLA) learn to respond to the cue during fear conditioning, and they mediate fear responding by transferring cue signals to th...

Learning to fear danger in the environment is essential to survival, but dysregulation of the fear system is at the core of many anxiety disorders. As a consequence, a great interest has emerged in developing strategies for suppressing fear memories in maladaptive cases. Recent research has focused in the process of reconsolidation where memories become labile after being retrieved. In a behavi...

We have demonstrated previously that brain-derived neurotrophic factor (BDNF) signaling in the amygdala is required for the consolidation of fear memory. This study is designed to characterize the signal cascades by which fear conditioning modulates transcriptional and translational expression of BDNF. Real-time reverse transcription-coupled polymerase chain reaction showed a significant increa...

Two-factor theory of avoidance remains one of the most infl uential theories of learning. It addresses a question of what works as a reinforcement of avoidance behavior, and proposes that: 1. an organism associates stimuli in the environment with aversive stimuli, and this allows these stimuli to evoke fear; 2. the avoidance response is reinforced by eliminating these warning stimuli or by esca...

The roles of the dorsal hippocampus and the central nucleus of the amygdala in the expression of contextual fear were assessed using two measures of conditioned fear: freezing and fear-potentiated startle. A discriminable context conditioning paradigm was developed that demonstrated both conditioned freezing and fear-potentiated startle in a context paired previously with foot shock, relative t...

Dental phobic patients with reported traumatic experiences at onset of dental anxiety were compared to subjects with an indirect fear acquisition in their psychophysiological responses to video scenes showing dental procedures. It has been suggested that individuals with conditioned fear would respond with higher levels of physiological arousal in response to threat compared to subjects with in...

Previous studies have demonstrated that rats subjected to single prolonged stress (SPS) exhibit posttraumatic stress disorder (PTSD)-like symptoms, such as enhanced contextual fear in response to trauma-related and trauma-unrelated events. Furthermore, we previously reported that upregulation of hippocampal glycine transporter 1 (GlyT-1) mRNA after context exposure could be the initial mechanis...