Pavlovian conditioning of fear based upon hormonal mediation of prior aversive experience

A series of three experiments was conducted to determine if epinephrine administered to animals given prior shock might support learning to new environmental cues paired with the epinephrine injection. Experiment 1, utilizing nonnaive rats, provided results snowing that such learning is possible. The effect, while dose-dependent, did not appear to be based on either epinephrine-induced place aversion or on sensitization. The results of Experiment 2 confirmed the basic finding when naive animals were utilized. Experiment 3 examined more carefully the potential contribution of generalized fear, impairment of extinction of fear, and nonspecific sensitization to the phenomenon. Since the findings did not support these alternative interpretations, it appears that epinephrine administration to previously stressed rats does indeed support new learning. The epinephrine-cue association may be mediated by either of two mechanisms: (1) higher order conditioning or (2) memory reactivation. The redintegrative function of epinephrine injections, in terms of modulating memory processing, is also discussed.     

Playing Healthy, Staying Healthy: A Prevention Program for Contagious Disease

This article provides guidelines for creating and promoting healthy environments in early childhood education in order to prevent and control the spread of contagious disease. Illness prevention strategies are offered along with practical suggestions for health education curriculum. Resources for children and adults are included for further reading.     

公园里的依稀身影

本文是一篇怀念美国前总统里根的文章,让我们通过普通百姓的眼光来看一下美国民众心目中的伟大形象。