Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA 01003,
Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, NJ 07102.
eNeuro. 2020 Jul 13;7(4). doi: 10.1523/ENEURO.0460-19.2020. Print 2020 Jul/Aug.
In the context of drug abuse, converging evidence suggests that cocaine use in new mothers is significantly reduced by the competing motivation related to child rearing. Given the demonstrated importance of the medial prefrontal cortex (mPFC) in decision-making processes, we investigated the contribution of distinct regions of the mPFC [anterior cingulate (Cg1), prelimbic (PrL), infralimbic (IL)] to decision making in new mother rats performing a concurrent pup/cocaine choice conditioned place preference (CPP) task. When given a choice, inactivation of IL cortex significantly biased decision making of mother rats toward cocaine-associated cues, highly contrasting the distribution of preferences by control groups. In contrast, inactivation of PrL cortex had the opposite effect, significantly increasing offspring bias in the decision making, such that none of the mothers chose the cocaine-associated alternative. Cg1 inactivation was without effect. Functional inactivation of these same mPFC subregions had no effect in a non-conflict CPP task in which context-induced cocaine or pup seeking were examined separately. Notably, inactivation of the IL cortex also interfered with maternal behavior. Taken together, we have identified a specific role of the IL cortex in the prioritization of offspring over drug competing alternatives, thus promoting resistance to drug use in new mothers.
在药物滥用的背景下，越来越多的证据表明，与育儿相关的竞争动机显著降低了新妈妈使用可卡因的频率。鉴于内侧前额叶皮层（mPFC）在决策过程中的重要性，我们研究了 mPFC 的不同区域（前扣带皮层（Cg1）、前额叶皮层（PrL）、下边缘皮层（IL））对新母鼠在执行同时进行的幼崽/可卡因选择条件位置偏好（CPP）任务时的决策的贡献。当给予选择时，IL 皮层的失活显著偏向于母鼠对可卡因相关线索的决策，与对照组的偏好分布形成鲜明对比。相比之下，PrL 皮层的失活则产生相反的效果，显著增加了幼崽在决策中的偏向，以至于没有一只母鼠选择可卡因相关的替代物。Cg1 失活则没有效果。在分别检查上下文诱导的可卡因或幼崽寻求的非冲突 CPP 任务中，这些相同的 mPFC 子区域的功能失活没有影响。值得注意的是，IL 皮层的失活也干扰了母性行为。综上所述，我们确定了 IL 皮层在将幼崽置于药物竞争替代物之上的优先级中的特定作用，从而促进了新妈妈对药物使用的抵制。
