Papini Santiago, R Galatzer-Levy Isaac, Papini Mauricio R
New York State Psychiatric Institute, Columbia University Medical Center, United States; City University of New York, City College, United States.
New York University, United States.
Behav Brain Res. 2014 Dec 15;275:212-8. doi: 10.1016/j.bbr.2014.09.006. Epub 2014 Sep 10.
In humans and other mammals, the unexpected loss of a resource can lead to emotional conflict. Consummatory successive negative contrast (cSNC) is a laboratory model of reward devaluation meant to capture that conflict. In this paradigm, animals are exposed to a sharp reduction in the sucrose concentration of a solution after several days of access. This downshift in sucrose content leads to behavioral responses such as the suppression of consumption and physiologic responses including elevation of corticosterone levels. However, response heterogeneity in cSNC has yet to be explored and may be relevant for increasing the validity of this model, as humans demonstrate clinically meaningful heterogeneity in response to resource loss. The current analysis applied latent growth mixture modeling to test for and characterize heterogeneity in recovery from cSNC among rats (N=262). Although most animals exhibited recovery of consummatory behavior after a sharp drop in consumption in the first postshift trial (Recovery class; 83%), two additional classes were identified including animals that did not change their consumption levels after downshift (No Contrast class; 6%), and animals that exhibited an initial response similar to that of the Recovery class but did not recover to preshift consumption levels (No Recovery class; 11%). These results indicate heterogeneity in recovery from reward loss among rats, which may increase the translatability of this animal model to understand diverse responses to loss among humans.
在人类和其他哺乳动物中，资源的意外丧失会导致情绪冲突。 consummatory successive negative contrast (cSNC) 是一种奖励贬值的实验室模型，旨在捕捉这种冲突。在这个范式中，动物在接触溶液蔗糖浓度几天后，会经历蔗糖浓度的急剧降低。蔗糖含量的这种下降会导致行为反应，如消费抑制，以及生理反应，包括皮质酮水平升高。然而，cSNC中的反应异质性尚未得到探索，可能与提高该模型的有效性相关，因为人类在对资源丧失的反应中表现出具有临床意义的异质性。当前的分析应用了潜在增长混合模型来测试和表征大鼠（N = 262）从cSNC中恢复的异质性。虽然大多数动物在转换后第一次试验中消费量急剧下降后表现出消费行为的恢复（恢复组；83%），但还识别出另外两组，包括转换后消费水平没有变化的动物（无对比组；6%），以及最初反应与恢复组相似但没有恢复到转换前消费水平的动物（无恢复组；11%）。这些结果表明大鼠在奖励丧失恢复方面存在异质性，这可能会增加这个动物模型在理解人类对丧失的不同反应方面的可翻译性。
