Early-life environmental conditions affect offspring's development. Maternal deprivation (MD) can induce persistent changes that give rise to neuropsychiatric diseases including substance abuse disorders. However, long-lasting mechanisms that determine vulnerability to drug addiction remain unknown. We hypothesized that MD could induce changes in Opioid system, HPA (hypothalamic-pituitary-adrenal) axis, and BDNF (brain-derived neurotrophic factor), so may be involved in the drug abuse in later life. Male offspring of Wistar rats (n = 8 per group) were subjected to 3 h of daily MD during postnatal days 1–14. In adulthood, morphine-induced CPP (conditioned place preference) was investigated using two doses of morphine (3 and 5 mg/kg). Serum corticosterone level was measured by ELISA method. The expression level of genes in selected brain regions (hippocampus, prefrontal cortex, and nucleus accumbens) was determined by qPCR (quantitative PCR). A greater morphine-induced CPP was observed in MD rats with 3 and 5 mg/kg morphine compared to controls. MD group had a higher corticosterone level. A significant decrease was observed in the expression of BDNF gene (in all of the selected brain regions) and GR (glucocorticoid receptor) gene (in the hippocampus and nucleus accumbens) in MD rats. Also, a significant increase in the expression of μ Opioid receptor (in all of the selected brain regions) and κ Opioid receptor (in the prefrontal cortex and nucleus accumbens) was observed in MD rats. Our results suggest that MD induces alterations in the HPA axis function, BDNF level, and Opioid receptors system that enhance vulnerability to morphine at adulthood.

生命早期的环境条件会影响后代的发育。母亲剥夺 (MD) 会引起持续性变化，从而导致神经精神疾病，包括药物滥用障碍。然而，确定药物成瘾易感性的持久机制仍然未知。我们假设 MD 可以引起阿片系统、HPA（下丘脑-垂体-肾上腺）轴和 BDNF（脑源性神经营养因子）的变化，因此可能参与晚年的药物滥用。Wistar 大鼠的雄性后代（每组 n = 8）在出生后第 1-14 天每天接受 3 小时的 MD。在成年期，使用两种剂量的吗啡（3 和 5 mg/kg）研究吗啡诱导的 CPP（条件性位置偏爱）。血清皮质酮水平采用ELISA法测定。通过 qPCR（定量 PCR）确定选定大脑区域（海马、前额叶皮层和伏隔核）中基因的表达水平。与对照组相比，在 3 和 5 mg/kg 吗啡的 MD 大鼠中观察到更大的吗啡诱导的 CPP。MD 组皮质酮水平较高。在 MD 大鼠中观察到 BDNF 基因（在所有选定的大脑区域）和 GR（糖皮质激素受体）基因（在海马体和伏隔核中）的表达显着降低。此外，在 MD 大鼠中观察到 μ 阿片受体（在所有选定的大脑区域）和 κ 阿片受体（在前额叶皮层和伏核中）的表达显着增加。我们的结果表明，MD 诱导 HPA 轴功能、BDNF 水平、