Responding for a conditioned reinforcer or unconditioned sensory reinforcer in mice: interactions with environmental enrichment, social isolation, and monoamine reuptake inhibitors
Responding for a conditioned reinforcer or unconditioned sensory reinforcer in mice: interactions with environmental enrichment, social isolation, and monoamine reuptake inhibitors
复制标题
DOI：
10.1007/s00213-015-4178-5
复制
发表时间：
2016-03-01
影响因子：
3.4
通讯作者：
Zeeb, Fiona D.
中科院分区：
文献类型：
--
作者：
Browne, Caleb J.;Fletcher, Paul J.;Zeeb, Fiona D.
环境因素影响许多精神疾病的病因。同样，环境因素可以改变动机的核心过程。因此，许多障碍中存在的动机缺陷可能受到早期生活环境条件的影响。我们研究了不同环境条件下饲养的动物是否会影响感官刺激获得激励价值的能力，以及单胺活性升高是否会改变对这些刺激的反应。研究了隔离饲养（IH）、成对饲养（PH）和环境富集（EE）雄性C57BL/6N小鼠对条件强化物（CRf）或非条件感觉强化物（USRf）的反应。CRf先前通过巴甫洛夫条件反射与糖精传递配对，而USRf不受奖励的限制。在对CRf或USRf反应的基线测试之后，研究了单胺活性升高的影响。在基线时，PH和EE小鼠对CRf或USRf的反应相似。IH小鼠对CRf的反应更多，但对USRf的反应获得较慢。西酞普兰（一种血清素转运体阻滞剂）或去甲肾上腺素转运体阻滞剂托莫西汀（一种去甲肾上腺素转运体阻滞剂）在所有组中均降低了对CRf和USRf的反应。多巴胺转运体阻滞剂GBR 12909普遍增加了对CRf和USRf的反应，但进一步的分析显示，只有在EE小鼠中，这两种强化物的反应都增强了。基准激励动机受住房条件的社会成分的强烈影响。此外，环境富集增加了对多巴胺活性升高的敏感性，而血清素和去甲肾上腺素的急性升高抑制了激励动机，而与住房条件无关。
Environmental factors influence the etiology of many psychiatric disorders. Likewise, environmental factors can alter processes central to motivation. Therefore, motivational deficits present in many disorders may be influenced by early life environmental conditions.We examined whether housing animals in different environmental conditions influenced the ability of sensory stimuli to acquire incentive value and whether elevated monoamine activity altered responsing for these stimuli.Isolation-housed (IH), pair-housed (PH), and environmentally enriched (EE) male C57BL/6N mice were examined in tests of responding for a conditioned reinforcer (CRf) or an unconditioned sensory reinforcer (USRf). The CRf was previously paired with saccharin delivery through Pavlovian conditioning, while the USRf was not conditioned with a reward. Following baseline tests of responding for the CRf or USRf, the effects of elevated monoamine activity were examined.At baseline, PH and EE mice responded similarly for the CRf or USRf. IH mice responded more for the CRf but exhibited slower acquisition of responding for the USRf. Administration of citalopram, a serotonin transporter blocker, or atomoxetine, a norepinephrine transporter blocker, decreased responding for the CRf and USRf in all groups. The dopamine transporter blocker GBR 12909 generally increased responding for the CRf and USRf, but further analysis revealed enhanced responding for both reinforcers only in EE mice.Baseline incentive motivation is strongly influenced by the social component of housing conditions. Furthermore, environmental enrichment increased the sensitivity to elevated dopamine activity, while acute elevations in serotonin and norepinephrine inhibit incentive motivation irrespective of housing condition.