Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109.
Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA 98195.
Proc Natl Acad Sci U S A. 2023 Dec 19;120(51):e2308305120. doi: 10.1073/pnas.2308305120. Epub 2023 Dec 11.
The motivation to reproduce is a potent natural drive, and the social behaviors that induce it can severely impact animal health and lifespan. Indeed, in males, accelerated aging associated with reproduction arises not from the physical act of courtship or copulation but instead from the motivational drive to court and mate. To better understand the mechanisms underlying social effects on aging, we studied male choosiness for mates. We found that increased activity of insulin-producing cells (IPCs) of the fly brain potentiated choosiness without consistently affecting courtship activity. Surprisingly, this effect was not caused by insulins themselves, but instead by drosulfakinin (DSK), another neuropeptide produced in a subset of the IPCs, acting through one of the two DSK receptors, CCKLR-17D1. Activation of IPC neurons also decreased food consumption, while activation of neurons outside of IPCs affected neither choosiness nor feeding, suggesting an overlap between neurons modulating choosiness and those influencing satiety. Broader activation of neurons (both within and outside of the IPCs) was required to rescue the detrimental effect of female pheromone exposure on male lifespan, as was the function of both DSK receptors. The same broad set of neurons was found to reinforce normally aversive feeding interactions, but only after exposure to female pheromones, suggesting that perception of the opposite sex gates rewarding properties of these neurons. We speculate that broad neuron activation is associated with states of satiety and social experience, which under stressful conditions is rewarding and beneficial for lifespan.
繁殖的动机是一种强烈的自然驱动力,而诱导这种动机的社会行为会严重影响动物的健康和寿命。事实上,在雄性动物中,与繁殖相关的加速衰老不是来自求偶或交配的身体行为,而是来自求偶和交配的动机驱动。为了更好地理解社会行为对衰老的影响机制,我们研究了雄性对配偶的选择性。我们发现,苍蝇大脑中产生胰岛素的细胞(IPCs)的活性增加增强了选择性,而不会一致影响求偶活动。令人惊讶的是,这种效果不是由胰岛素本身引起的,而是由另一种神经肽 drosulfakinin(DSK)引起的,DSK 是在 IPC 的一部分细胞中产生的,通过两种 DSK 受体之一 CCKLR-17D1 起作用。IPC 神经元的激活还会减少食物摄入,而 IPC 之外的神经元的激活既不会影响选择性也不会影响进食,这表明调节选择性和影响饱腹感的神经元之间存在重叠。IPC 神经元(包括 IPC 内和 IPC 外的神经元)的广泛激活被认为可以挽救雌性信息素暴露对雄性寿命的不利影响,而 DSK 受体的功能也是必需的。同样广泛的神经元被发现可以强化正常情况下令人厌恶的进食相互作用,但只有在暴露于雌性信息素后才会发生,这表明对异性的感知可以控制这些神经元的奖励属性。我们推测,广泛的神经元激活与饱腹感和社交体验状态有关,在压力条件下,这种状态是有益的,可以延长寿命。