Brief isolation during infancy enhances the formation of long-term memories in infant rodents
Sarah E Bae, Rick Richardson
Behavioral tagging, which is well-established in adults, has recently been shown to also occur in infants. Interestingly, while familiarizing the novel experience abolishes behavioral tagging in adults, it appears to be without effect in infants. Familiarization, at least in infants, may act as an experience-dependent switch, closing the hippocampal critical period and thus accelerating the maturation of the hippocampus. In this study, infant (i.e., Postnatal Day 17) rats were placed in a context and shocked. Infants familiarized to an open field arena for 30 min the day before exhibited enhanced retention when tested 1 day later (Experiments 1 and 2). While brief exploration of an open field soon before learning (i.e., the behavioral tagging procedure) resulted in better memory when rats were tested 1, but not 3, days later, familiarized rats had enhanced long-term memory (LTM) at both intervals (Experiment 3). Furthermore, familiarization, but not brief open field exposure, enhanced LTM for a nonhippocampal task (Experiment 4), suggesting that familiarization works through a different mechanism compared with behavioral tagging. Specifically, these results suggest that familiarization results in broader changes to the emotiona...Continue Reading
The neuronal circuits within the cortico-limbic brain regions form networks that mediate emotional behavior. Areas specific to emotional learning include the basal amygdala and sublenticular extended amygdala region along with a supplemental motor area. Discover the latest research on brain circuits in emotional learning here.