Woolley S C, Kao M H
Department of Biology, McGill University, 1205 Avenue Dr. Penfield, Montreal, QC H3A 1B1, Canada.
Department of Physiology, University of California, San Francisco, 675 Nelson Rising Lane, Room 518, San Francisco, CA 94158, USA.
Neuroscience. 2015 Jun 18;296:39-47. doi: 10.1016/j.neuroscience.2014.10.010. Epub 2014 Oct 18.
Many motor behaviors, from walking to speaking, are acquired through experience, in particular, through trial-and-error learning. The acquisition and maintenance of such motor behaviors in a wide range of species, including humans, appear to depend on cortical-basal ganglia circuits. In this review, we discuss recent studies in songbirds that have been pivotal in informing our current understanding of motor learning and cortical-basal ganglia function. Songbirds are important ethological model systems for the study of motor learning because young songbirds naturally develop and refine their songs through trial-and-error learning. In addition, reinforcement mechanisms are hypothesized to be important for the maintenance and plasticity of structured adult song. Computational and experimental studies highlight the importance of vocal motor variability as the substrate upon which reinforcement mechanisms could operate to shape developing song and to maintain adult song. Recent studies in songbirds indicate that this vocal motor variability is actively generated and modulated by a highly specialized cortical-basal ganglia circuit evolved for a single behavior, song. We argue that these and other recent findings illustrate how the tight association between a specialized neural circuit and a natural behavior make songbirds a unique and powerful model in which to investigate the neural substrates of motor learning and plasticity.
许多运动行为，从行走至说话，都是通过经验习得的，尤其是通过试错学习。包括人类在内的众多物种中，此类运动行为的习得与维持似乎都依赖于皮质-基底神经节回路。在这篇综述中，我们讨论了近期在鸣禽身上开展的研究，这些研究对于我们当前理解运动学习和皮质-基底神经节功能起到了关键作用。鸣禽是研究运动学习的重要行为学模型系统，因为幼龄鸣禽会通过试错学习自然地发展并完善它们的歌声。此外，强化机制被认为对于结构化成年歌声的维持和可塑性很重要。计算和实验研究强调了发声运动变异性的重要性，它是强化机制赖以塑造发育中的歌声并维持成年歌声的基础。近期对鸣禽的研究表明，这种发声运动变异性是由一个为单一行为——歌声——进化而来的高度特化的皮质-基底神经节回路主动产生并调节的。我们认为，这些以及其他近期的发现说明了一个特化神经回路与一种自然行为之间的紧密联系是如何使鸣禽成为研究运动学习和可塑性神经基础的独特且强大的模型的。
