Figure 4.

Effects of stress on fear extinction in infant and adolescent rodents. (a) At preweaning ages, infant rodents exhibit an erasure-like form of extinction that is less prone to spontaneous recovery and context-renewal than extinction in post-weaning animals (Kim and Richardson, 2007). (b) Exposing infants to stressors leads to the emergence of the adult form of extinction at preweaning (Callaghan et al, 2013). (c) Adolescent rats exposed to chronic stress typically show impaired extinction when tested as adults (Ishikawa et al, 2012; Judo et al, 2010; Toledo-Rodriguez et al, 2012), although there is preliminary evidence that acute stress in adolescence can facilitate extinction (Schayek and Maroun, 2014).