PDF(Pubmed)
Abstract：
The impact of environmental enrichment (EE) on natural rewards, including social and appetitive rewards, was investigated in male Swiss mice. EE, known for providing animals with various stimuli, was assessed for its effects on conditioned place preference (CPP) associated with ethanol and social stimuli. We previously demonstrated that EE increased the levels of the prosocial neuropeptide oxytocin (OT) in the hypothalamus and enhanced ethanol rewarding effects via an oxytocinergic mechanism. This study also investigated the impact of EE on social dominance and motivation for rewards, measured OT-mediated phospholipase C (PLC) activity in striatal membranes, and assessed OT expression in the hypothalamus. The role of dopamine in motivating rewards was considered, along with the interaction between OT and D1 receptors (DR) in the nucleus accumbens (NAc). Results showed that EE mice exhibited a preference for ethanol reward over social reward, a pattern replicated by the OT analogue Carbetocin. EE mice demonstrated increased social dominance and reduced motivation for appetitive taste stimuli. Higher OT mRNA levels in the hypothalamus were followed by diminished OT receptor (OTR) signaling activity in the striatum of EE mice. Additionally, EE mice displayed elevated D1R expression, which was attenuated by the OTR antagonist (L-368-889). The findings underscore the reinforcing effect of EE on ethanol and social rewards through an oxytocinergic mechanism. Nonetheless, they suggest that mechanisms other than the prosocial effect of EE may contribute to the ethanol pro-rewarding effect of EE and Carbetocin. They also point towards an OT-dopamine interaction potentially underlying some of these effects.
摘要：
环境富集（EE）对自然奖励的影响，包括社会和食欲奖励，在雄性瑞士小鼠中进行了研究。EE,以给动物提供各种刺激而闻名，评估了其对与乙醇和社会刺激相关的条件性位置偏好（CPP）的影响。我们先前证明，EE增加了下丘脑中亲社会神经肽催产素（OT）的水平，并通过催产素能机制增强了乙醇的奖励作用。这项研究还调查了EE对社会支配地位和奖励动机的影响，在纹状体膜中测量OT介导的磷脂酶C（PLC）活性，并评估下丘脑中的OT表达。考虑了多巴胺在激励奖励中的作用，随着伏隔核（NAc）中OT和D1受体（DR）之间的相互作用。结果表明，EE小鼠表现出对乙醇奖励的偏好，而不是社会奖励，由OT类似物卡贝缩宫素复制的模式。EE小鼠表现出增强的社交优势和降低的食欲刺激动机。下丘脑中的OTmRNA水平较高，随后EE小鼠纹状体中的OT受体（OTR）信号活性降低。此外,EE小鼠表现出升高的D1R表达，其被OTR拮抗剂(L-368-889)减毒。研究结果强调了EE通过催氧作用机制对乙醇和社会奖励的增强作用。尽管如此，他们认为，EE的亲社会效应以外的机制可能有助于EE和Carbetocin的乙醇促进奖励效应。他们还指出了OT-多巴胺相互作用可能是其中一些影响的潜在基础。
