Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America.
PLoS One. 2010 Feb 10;5(2):e9141. doi: 10.1371/journal.pone.0009141.
All organisms are confronted with dynamic environmental changes that challenge homeostasis, which is the operational definition of stress. Stress produces adaptive behavioral and physiological responses, which, in the Metazoa, are mediated through the actions of various hormones. Based on its associated phenotypes and its expression profiles, a candidate stress hormone in Drosophila is the corazonin neuropeptide. We evaluated the potential roles of corazonin in mediating stress-related changes in target behaviors and physiologies through genetic alteration of corazonin neuronal excitability. Ablation of corazonin neurons confers resistance to metabolic, osmotic, and oxidative stress, as measured by survival. Silencing and activation of corazonin neurons lead to differential lifespan under stress, and these effects showed a strong dependence on sex. Additionally, altered corazonin neuron physiology leads to fundamental differences in locomotor activity, and these effects were also sex-dependent. The dynamics of altered locomotor behavior accompanying stress was likewise altered in flies with altered corazonin neuronal function. We report that corazonin transcript expression is altered under starvation and osmotic stress, and that triglyceride and dopamine levels are equally impacted in corazonin neuronal alterations and these phenotypes similarly show significant sexual dimorphisms. Notably, these sexual dimorphisms map to corazonin neurons. These results underscore the importance of central peptidergic processing within the context of stress and place corazonin signaling as a critical feature of neuroendocrine events that shape stress responses and may underlie the inherent sexual dimorphic differences in stress responses.
所有生物体都面临着动态的环境变化，这些变化挑战着体内平衡，这是应激的操作定义。应激会产生适应性的行为和生理反应，在后生动物中，这些反应是通过各种激素的作用来介导的。根据其相关表型和表达谱，候选应激激素在果蝇中是心激素神经肽。我们通过改变心激素神经元的兴奋性来评估心激素在介导与应激相关的靶行为和生理变化中的潜在作用。心激素神经元的缺失赋予了对代谢、渗透和氧化应激的抗性，这可以通过生存来衡量。心激素神经元的沉默和激活导致应激下的寿命差异，这些效应强烈依赖于性别。此外，改变的心激素神经元生理学导致运动活性的根本差异，这些效应也依赖于性别。伴随应激改变的运动行为的动态同样也在改变心激素神经元功能的果蝇中发生了改变。我们报告说，在心激素神经元改变的情况下，饥饿和渗透应激会改变心激素转录本的表达，并且三酰甘油和多巴胺水平同样受到心激素神经元改变的影响，这些表型同样表现出显著的性别二态性。值得注意的是，这些性别二态性映射到心激素神经元上。这些结果强调了中枢肽能处理在应激背景下的重要性，并将心激素信号作为塑造应激反应的神经内分泌事件的关键特征，可能是应激反应中固有的性别二态性差异的基础。
