Honarmand Mariam, Thompson Christopher K, Schatton Adriana, Kipper Silke, Scharff Constance
Department of Animal Behavior, Freie Universität, Berlin, Germany.
Department of Molecular and Cellular Neuroscience, the Scripps Research Institute, La Jolla, California.
Dev Neurobiol. 2016 Jan;76(1):107-18. doi: 10.1002/dneu.22302. Epub 2015 Jun 1.
Adverse environmental conditions can impact the life history trajectory of animals. Adaptive responses enable individuals to cope with unfavorable conditions, but altered metabolism and resource allocation can bear long-term costs. In songbirds, early developmental stress can cause lifelong changes in learned song, a culturally transmitted trait, and nestlings experiencing developmental stress develop smaller song control nucleus HVCs. We investigated whether nutrition-related developmental stress impacts neurogenesis in HVC, which may explain how poor nutrition leads to smaller HVC volume. We provided different quality diets (LOW and HIGH) by varying the husks-to-seeds ratio to zebra finch families for the first 35 days after the young hatched (PHD). At PHD14-18 and again at nutritional independence (PHD35), juveniles were injected with different cell division markers. To monitor growth, we took body measures at PHD10, 17, and 35. At PHD35 the number of newly recruited neurons in HVC and the rate of proliferation in the adjacent ventricular zone (VZ) were counted. Males raised on the LOW diet for their first weeks of life had significantly fewer new neurons in HVC than males raised on the HIGH diet. At the time when these new HVC neurons were born and labeled in the VZ (PHD17) the birds exposed to the LOW diet had significantly lower body mass. At PHD35 body mass or neuronal proliferation no longer differed. Our study shows that even transitory developmental stress can have negative consequences on the cellular processes underlying the development of neural circuits.
不利的环境条件会影响动物的生活史轨迹。适应性反应使个体能够应对不利条件，但新陈代谢和资源分配的改变可能会带来长期代价。在鸣禽中，早期发育应激会导致习得性鸣叫这种文化传递特征发生终身变化，经历发育应激的雏鸟会发育出较小的鸣叫控制核团HVC。我们研究了与营养相关的发育应激是否会影响HVC中的神经发生，这可能解释营养不良如何导致HVC体积变小。在雏鸟孵化后的前35天（孵化后天数，PHD），我们通过改变雀科鸟类家庭的谷壳与种子比例，为它们提供不同质量的饮食（低质量和高质量）。在PHD14 - 18以及营养独立时（PHD35），对幼鸟注射不同的细胞分裂标记物。为了监测生长情况，我们在PHD10、17和35时对雏鸟进行身体测量。在PHD35时，统计HVC中新招募神经元的数量以及相邻脑室区（VZ）的增殖率。在生命的第一周以低质量饮食饲养的雄性雏鸟，其HVC中的新神经元数量显著少于以高质量饮食饲养的雄性雏鸟。在这些新的HVC神经元在VZ中产生并被标记时（PHD17），接受低质量饮食的鸟类体重显著较低。在PHD35时，体重或神经元增殖不再有差异。我们的研究表明，即使是短暂的发育应激也会对神经回路发育的细胞过程产生负面影响。
