Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598853 (forgetting)
 3,232 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently, studies from our laboratory have shown that 16-day-old rats, in contrast to 23-day-old rats, fail to show either ABA renewal or recovery of an extinguished fear response following a pre-test injection of FG7142 [Kim, J. H. & Richardson, R. (2007). A developmental dissociation of context and GABA effects on extinguished fear in rats. Behavioral Neuroscience; Yap & Richardson, unpublished data]. The present study, using freezing as a measure of learned fear, extends these findings by examining whether there is a developmental difference in susceptibility to reinstatement following extinction. 16- and 23-day-old rats were trained to fear a white-noise conditioned stimulus (CS) by pairing it with a shock unconditioned stimulus (US). This fear was subsequently extinguished by non-reinforced presentations of the CS. Some rats received a post-extinction Reminder which consisted of a single presentation of a reduced-intensity US. Experiments 1 and 2 demonstrated that this Reminder was effective in reinstating extinguished fear in 23-day-olds, and that this reinstatement effect was context-specific in rats this age. In contrast, 16-day-old rats failed to show the reinstatement effect in either experiment. The failure to observe a post-extinction reinstatement effect in the 16-day-olds was not due to a general ineffectiveness of the Reminder treatment at this age because it did alleviate spontaneous forgetting in rats this age (Experiment 3). Taken together, the results suggest that fundamentally different processes may mediate extinction early in development compared to later in development.
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PMID:A developmental dissociation in reinstatement of an extinguished fear response in rats. 1745 34

Extinction allows organisms to adapt to an ever-changing environment. Despite its theoretical and applied significance, extinction has never been systematically studied with human infants. Using the operant mobile task, we examined whether 3-month-olds would exhibit evidence of original learning following extinction. In a recognition paradigm, infants exhibited renewal when tested in the acquisition context (ABA renewal) or a neutral context (ABC and AAB renewal) 1 day following extinction (Experiment 1a) and spontaneous recovery 3 days following extinction (Experiment 1b). In Experiments 2a-2b, we used a reminder paradigm to examine whether the extinguished response could be reinstated after the operant response had been forgotten. We failed, however, to find reinstatement of extinguished responding after spontaneous forgetting, regardless of the reminder and test contexts. We attributed this retention failure to competing responses at test. Although extinguished responding is recovered during infancy, this effect is elusive after the response has been forgotten.
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PMID:A dissociation between recognition and reactivation: The renewal effect at 3 months of age. 2639 3