Long Michael A, Fee Michale S
McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nature. 2008 Nov 13;456(7219):189-94. doi: 10.1038/nature07448.
Many complex behaviours, like speech or music, have a hierarchical organization with structure on many timescales, but it is not known how the brain controls the timing of behavioural sequences, or whether different circuits control different timescales of the behaviour. Here we address these issues by using temperature to manipulate the biophysical dynamics in different regions of the songbird forebrain involved in song production. We find that cooling the premotor nucleus HVC (formerly known as the high vocal centre) slows song speed across all timescales by up to 45 per cent but only slightly alters the acoustic structure, whereas cooling the downstream motor nucleus RA (robust nucleus of the arcopallium) has no observable effect on song timing. Our observations suggest that dynamics within HVC are involved in the control of song timing, perhaps through a chain-like organization. Local manipulation of brain temperature should be broadly applicable to the identification of neural circuitry that controls the timing of behavioural sequences and, more generally, to the study of the origin and role of oscillatory and other forms of brain dynamics in neural systems.
许多复杂行为，如言语或音乐，具有层次组织，在多个时间尺度上都有结构，但目前尚不清楚大脑如何控制行为序列的时间安排，也不清楚不同的神经回路是否控制行为的不同时间尺度。在这里，我们通过利用温度来操纵参与鸣禽鸣叫产生的前脑不同区域的生物物理动力学，来解决这些问题。我们发现，冷却运动前核HVC（以前称为高级发声中枢）会使所有时间尺度上的鸣叫速度减慢多达45%，但只会轻微改变声学结构，而冷却下游运动核RA（弓状皮质的粗壮核）对鸣叫时间没有可观察到的影响。我们的观察结果表明，HVC内的动力学可能通过类似链条的组织参与鸣叫时间的控制。局部操纵脑温应该广泛适用于识别控制行为序列时间的神经回路，更普遍地说，适用于研究振荡和其他形式的脑动力学在神经系统中的起源和作用。
