Wood William E, Olson Christopher R, Lovell Peter V, Mello Claudio V
Neurological Sciences Institute, Oregon Health and Science University, Beaverton, Oregon 97006, USA.
Dev Neurobiol. 2008 Sep 1;68(10):1213-24. doi: 10.1002/dneu.20642.
Vitamin A, an essential nutrient, is required in its acidic form (retinoic acid) for normal embryogenesis and neuronal development, typically within well-defined concentration ranges. In zebra finches, a songbird species, localized retinoic acid synthesis in the brain is important for the development of song, a learned behavior sharing significant commonalities with speech acquisition in humans. We tested how dietary retinoic acid affects the development of song behavior and the brain's system for song control. Supplemental doses of retinoic acid given to juveniles during the critical period for song learning resulted in more variable or plastic-like songs when the birds reached adulthood, compared to the normal songs of vehicle-fed controls. We also observed that several genes (brinp1, nrgn, rxr-alpha, and sdr2/scdr9) had altered levels of expression in specific nuclei of the song system when comparing the experimental and control diet groups. Interestingly, we found significant correlations between gene expression levels in nuclei of the anterior forebrain pathway (lMAN and area X) and the degree of variability in the recorded songs. We observed, however, no major morphological effects such as changes in the volumes of song nuclei. Overall, our results lend further support to a fundamental role of retinoic acid in song maturation and point to possible molecular pathways associated with this action. The data also demonstrate that dietary content of Vitamin A can affect the maturation of a naturally learned complex behavior.
维生素A是一种必需营养素，其酸性形式（视黄酸）在正常胚胎发育和神经元发育中是必需的，通常在明确的浓度范围内。在斑胸草雀（一种鸣禽）中，大脑中局部视黄酸的合成对于鸣叫的发育很重要，鸣叫是一种习得行为，与人类语言习得有许多显著的共同之处。我们测试了饮食中的视黄酸如何影响鸣叫行为的发育以及大脑的鸣叫控制系统。与喂食载体的对照组的正常鸣叫相比，在鸣叫学习的关键时期给幼鸟补充视黄酸剂量，当这些鸟成年后会导致更具变异性或类似可塑性的鸣叫。当比较实验饮食组和对照饮食组时，我们还观察到几个基因（brinp1、nrgn、rxr-α和sdr2/scdr9）在鸣叫系统的特定核团中的表达水平发生了改变。有趣的是，我们发现前脑通路核团（lMAN和X区）中的基因表达水平与所记录鸣叫的变异程度之间存在显著相关性。然而，我们没有观察到诸如鸣叫核团体积变化等主要形态学影响。总体而言，我们的结果进一步支持了视黄酸在鸣叫成熟中的基本作用，并指出了与这种作用相关的可能分子途径。数据还表明，维生素A的饮食含量会影响一种自然习得的复杂行为的成熟。
