Addiction Biology, Instituto de Investigação e Inovação em Saúde (i3S) e Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135, Porto, Portugal.
Laboratory of Neuropsychophysiology, Faculty of Psychology and Education Sciences, University of Porto, 4200-135, Porto, Portugal.
Sci Rep. 2020 Aug 7;10(1):13326. doi: 10.1038/s41598-020-70242-4.
The development of substance abuse problems occurs due to a diverse combination of risk factors. Among these risks, studies have reported depression and early-life stress as of importance. These two factors often occur simultaneously, however, there is a lack of understanding of how their combined effect may impact vulnerability to drug abuse in adolescence. The present study used rats with different vulnerability to depression (Wistar and Wistar-Kyoto) to investigate the impact of maternal separation (MS) on emotional state and drug addiction vulnerability during the adolescence period. Mothers and their litters were subjected to MS (180 min/day) from postnatal day 2 to 14. The offspring emotional state was assessed by observing their exploratory behavior. Drug abuse vulnerability was assessed through conditioning to cocaine. MS impacted the emotional state in both strains. Wistar responded with increased exploration, while Wistar-Kyoto increased anxiety-like behaviours. Despite the different coping strategies displayed by the two strains when challenged with the behavioural tests, drug conditioning was equally impacted by MS in both strains. Early-life stress appears to affect drug abuse vulnerability in adolescence independently of a depression background, suggesting emotional state as the main driving risk factor.
物质滥用问题的发展是由于多种风险因素的综合作用。在这些风险因素中，研究报告称抑郁和童年早期压力很重要。这两个因素经常同时发生，然而，人们对于它们的综合影响如何影响青少年时期对药物滥用的易感性知之甚少。本研究使用对抑郁有不同易感性的大鼠（Wistar 和 Wistar-Kyoto），来研究母鼠分离（MS）对青春期情绪状态和药物成瘾易感性的影响。从出生后第 2 天到第 14 天，母鼠及其幼崽每天接受 180 分钟的 MS。通过观察幼崽的探索行为来评估其情绪状态。通过可卡因条件作用来评估药物滥用易感性。MS 影响了两种品系的情绪状态。Wistar 表现出更多的探索行为，而 Wistar-Kyoto 则表现出更多的焦虑样行为。尽管两种品系在应对行为测试时表现出不同的应对策略，但 MS 对两种品系的药物条件作用都有同样的影响。童年早期压力似乎独立于抑郁背景影响青春期的药物滥用易感性，这表明情绪状态是主要的风险因素。
