Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biology, McGill University, Montreal, QC H3A 1B1, Canada.
Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Indian Institute of Science Education and Research, Pashan Road, Pune 411008, Maharashra, India.
Neuron. 2014 Apr 2;82(1):208-23. doi: 10.1016/j.neuron.2014.01.039.
Context dependence is a key feature of cortical-basal ganglia circuit activity, and in songbirds the cortical outflow of a basal ganglia circuit specialized for song, LMAN, shows striking increases in trial-by-trial variability and bursting when birds sing alone rather than to females. To reveal where this variability and its social regulation emerge, we recorded stepwise from corticostriatal (HVC) neurons and their target spiny and pallidal neurons in Area X. We find that corticostriatal and spiny neurons both show precise singing-related firing across both social settings. Pallidal neurons, in contrast, exhibit markedly increased trial-by-trial variation when birds sing alone, created by highly variable pauses in firing. This variability persists even when recurrent inputs from LMAN are ablated. These data indicate that variability and its context sensitivity emerge within the basal ganglia network, suggest a network mechanism for this emergence, and highlight variability generation and regulation as basal ganglia functions.
语境依赖性是皮质-基底神经节回路活动的一个关键特征，在鸣禽中，专门用于歌唱的基底神经节回路的皮质输出，当鸟类独自歌唱而不是对雌性歌唱时，其在试验间的可变性和爆发性显著增加。为了揭示这种可变性及其社会调节出现的位置，我们在 Area X 中从皮质纹状体（HVC）神经元及其靶棘状和苍白球神经元逐步记录。我们发现，皮质纹状体和棘状神经元在两种社会环境下都表现出精确的与歌唱相关的放电。相比之下，当鸟类独自歌唱时，苍白球神经元的放电表现出明显的试验间可变性，这是由放电中高度可变的停顿造成的。即使消除了来自 LMAN 的复发性输入，这种可变性仍然存在。这些数据表明，可变性及其对上下文的敏感性是在基底神经节网络中产生的，为这种出现提供了一种网络机制，并强调了作为基底神经节功能的可变性产生和调节。
