Department of Psychology, University of Michigan, 530 Church St., Ann Arbor, MI, USA.
Dev Psychobiol. 2011 Jan;53(1):13-22. doi: 10.1002/dev.20481.
Early life environment and maternal care can have long-lasting effects on behavior and physiology. Previously, we found that compared to mother-reared (MR) female rats, rats reared without mothers, siblings, and nest, through artificially rearing (AR), show reduced levels of maternal behavior when they grow up. These effects can be reversed if AR pups are provided with extra "licking-like" tactile stimulation during the preweaning period [Gonzalez et al. [2001] Developmental Psychobiology, 38(1), 11-42]. We also found that AR rats are more action impulsive and have reduced attentional capacities in comparison to their MR siblings [Lovic, Fletcher, & Fleming, in preparation; Lovic & Fleming [2004] Behavioural Brain Research 148: 209-219]. However, it is unknown whether increased impulsivity contributes to reduced levels of maternal behaviors. The purpose of this study was to assess the relationship between impulsivity and maternal behavior in AR and MR rats. Female rats were reared with (MR) or without mothers (AR) and half of the AR rats received additional stroking stimulation. As adults, AR and MR rats were mated and maternal behavior towards their own pups was assessed. In addition, rats were assessed on impulsive action (differential reinforcement of low-rate schedule; DRL-20s). Consistent with previous findings, AR rats were both less maternal and more action impulsive than MR rats. Partial correlations revealed that impulsivity was inversely related to pup licking-impulsive rats were less maternal.
早期生活环境和母婴护理会对行为和生理产生持久影响。此前，我们发现与由母亲抚养的（MR）雌性大鼠相比，通过人工抚养（AR）、没有母亲、兄弟姐妹和巢穴的大鼠在长大后表现出较低水平的母性行为。如果在断奶前给 AR 幼鼠提供额外的“舔舐样”触觉刺激，这些影响可以逆转[Gonzalez 等人，2001 年，《发展心理生物学》，38（1），11-42]。我们还发现，与 MR 兄弟姐妹相比，AR 大鼠更冲动，注意力能力降低[Lovic、Fletcher 和 Fleming，正在准备中；Lovic 和 Fleming[2004]，《行为脑研究》148:209-219]。然而，尚不清楚冲动是否会导致母性行为水平降低。本研究旨在评估 AR 和 MR 大鼠冲动性与母性行为之间的关系。雌性大鼠与（MR）或没有母亲（AR）一起饲养，一半的 AR 大鼠接受额外的抚摸刺激。成年后，AR 和 MR 大鼠交配，评估它们对自己幼崽的母性行为。此外，还对大鼠进行了冲动性动作（DRL-20s，区分强化低速率方案）评估。与之前的发现一致，AR 大鼠的母性行为和冲动性动作都比 MR 大鼠低。偏相关表明，冲动性与幼鼠舔舐呈负相关，冲动性强的大鼠母性行为较差。
