Subscribe to thousands of academic journals for just $40/month
Read and share the articles you need for your research, all in one place.

Maternal Separation Results in Early Emergence of Adult-Like Fear and Extinction Learning in Infant Rats

Behavioral Neuroscience , Volume 125 (1): 20 – Feb 1, 2011


American Psychological Association
Copyright © 2011 by American Psychological Association
Publisher site
See Article on Publisher Site

Preview Only

Expand Tray Hide Tray

Maternal Separation Results in Early Emergence of Adult-Like Fear and Extinction Learning in Infant Rats


Recent studies in rats have shown that extinction occurring early in life is resistant to relapse and may represent the erasure of fear memories. In the present study we examined the effects of early life stress on extinction in the developing rat, which could have important implications for the treatment of anxiety disorders in those who have experienced early life stress. In the present study, we used maternal-separation on postnatal days (P) 2–14 as an early life stressor. On P17, maternally separated and standard-reared animals were trained to fear a noise associated with a footshock. The fear of this noise was then extinguished (through repeated nonreinforced noise presentations) on P18. Animals were tested for contextually mediated, stress-mediated, and GABA-mediated fear relapse the day after extinction. We found that young animals exposed to maternal-separation were more likely to exhibit context- and stress-mediated relapse after extinction than standard-reared animals (Experiments 1 and 2). Further, unlike standard-reared animals, maternally separated rats exhibited a return of fear when the inhibitory neurotransmitter GABA was blocked at test (Experiment 3). These effects were not the result of maternal separation increasing rats' sensitivity to footshock (Experiment 5) and may in part be related to superior long-term memory for contexts in P17 maternally separated rats (Experiment 4). Taken together, these results suggest that early life adversity may prepare young animals to respond more cautiously toward fear signals in their environment.
Loading next page...

Preview Only. This article cannot be rented because we do not currently have permission from the publisher.