Tran Steven, Nowicki Magda, Muraleetharan Arrujyan, Chatterjee Diptendu, Gerlai Robert
Department of Cell and Systems Biology, University of Toronto, Canada.
Department of Psychology, University of Toronto Mississauga, Canada.
Prog Neuropsychopharmacol Biol Psychiatry. 2016 Feb 4;65:25-33. doi: 10.1016/j.pnpbp.2015.08.009. Epub 2015 Aug 24.
Variation among individuals may arise for several reasons, and may have diverse underlying mechanisms. Individual differences have been studied in a variety of species, but recently a new model organism has emerged in this field that offers both sophistication in phenotypical characterization and powerful mechanistic analysis. Recently, zebrafish, one of the favorites of geneticists, have been shown to exhibit consistent individual differences in baseline locomotor activity. In the current study, we further explore this finding and examine whether individual differences in locomotor activity correlate with anxiety-like behavioral measures and with levels of dopamine, serotonin and the metabolites of these neurotransmitters. In addition, we examine whether individual differences in locomotor activity are also associated with reactivity to the locomotor stimulant effects of and neurochemical responses to acute ethanol exposure (30min long, 1% v/v ethanol bath application). Principal component analyses revealed a strong association among anxiety-like responses, locomotor activity, serotonin and dopamine levels. Furthermore, ethanol exposure was found to abolish the locomotion-dependent anxiety-like behavioral and serotonergic responses suggesting that this drug also engages a common underlying pathway. Overall, our results provide support for an important role of the serotonergic system in mediating individual differences in anxiety-like responses and locomotor activity in zebrafish and for a minor modulatory role of the dopaminergic system.
个体间的差异可能由多种原因引起，并且可能有不同的潜在机制。个体差异已在多种物种中得到研究，但最近在这个领域出现了一种新的模式生物，它在表型特征描述方面既复杂又具有强大的机制分析能力。最近，斑马鱼，遗传学家们的最爱之一，已被证明在基线运动活动中表现出一致的个体差异。在当前的研究中，我们进一步探讨这一发现，并研究运动活动中的个体差异是否与焦虑样行为指标以及多巴胺、血清素和这些神经递质的代谢产物水平相关。此外，我们研究运动活动中的个体差异是否也与对急性乙醇暴露（30分钟长，1% v/v乙醇浴应用）的运动刺激效应的反应性和神经化学反应相关。主成分分析揭示了焦虑样反应、运动活动、血清素和多巴胺水平之间的强烈关联。此外，发现乙醇暴露消除了依赖运动的焦虑样行为和血清素能反应，表明这种药物也涉及一个共同的潜在途径。总体而言，我们的结果支持血清素能系统在介导斑马鱼焦虑样反应和运动活动中的个体差异方面的重要作用，以及多巴胺能系统的次要调节作用。
