Figure 2From: Stability and change: Stress responses and the shaping of behavioral phenotypes over the life spanMean (+/- se) plasma cortisol concentrations of male guinea pigs of different ages prior to, and 60 and 120 min following, isolation in a novel enclosure. The response of sexually mature males (~120 days) is suppressed relative to those of periadolescent (~55 days) and older, sexually mature males (~300 days). Adapted from [68].Back to article page