Neurotoxicity research
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A conditioned stimulus (CS) associated with a fearsome unconditioned stimulus (US) generates learned fear. Acquired fear is at the root of a variety of mental disorders, among which phobias, generalized anxiety, the posttraumatic stress disorder (PTSD) and some forms of depression. The simplest way to inhibit learned fear is to extinguish it, which is usually done by repeatedly presenting the CS alone, so that a new association, CS-"no US", will eventually overcome the previously acquired CS-US association. ⋯ In fact, our findings indicate that the reconsolidation hypothesis is essentially incorrect, at least for the form of contextual fear most commonly studied in rodents. Therefore, it seems safe to continue using extinction-based forms of therapy for disorders secondary to acquired fear. Further, it is useful and desirable to device procedures by which the "no US" component of the extinction is strengthened in order to alleviate the symptoms of victims of acquired fear.