人说话和鸟唱歌等复杂行为要求在多种时间尺度上、在正确的时刻完成一组有序的运动。控制这种类型行为的“时钟”的性质仍然不是很清楚。
现在，一项具有广泛用途的方法被用来确定决定鸟鸣时程的时钟回路。该方法所利用的是脑过程的速度强烈依赖于温度这样一个事实。当斑胸草雀运动前区高级发声中枢（HVC）的活动因温度降低而减慢时，其叫声的总体速度也降低，但叫声内的声学元素结构保持不变。这说明HVC是脑中控制决定鸟鸣时程的复杂行为序列的区域。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 456, 189-194 (13 November 2008) | doi:10.1038/nature07448
Using temperature to analyse temporal dynamics in the songbird motor pathway
Michael A. Long1 & Michale S. Fee1
1 McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2 Correspondence to: Michale S. Fee1 Correspondence and requests for materials should be addressed to M.S.F. (Email: fee@mit.edu).
Abstract
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.
