Singing-related activity of identified HVC neurons in the zebra finch
Singing-related activity of identified HVC neurons in the zebra finch
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DOI：
10.1152/jn.00952.2006
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发表时间：
2007-06-01
影响因子：
2.5
通讯作者：
Fee, Michale S.
中科院分区：
文献类型：
--
作者：
Kozhevnikov, Alexay A.;Fee, Michale S.
高级发声中枢（High vocal center，HVC）是发声所必需的前运动通路的一部分，也是前前脑通路（anterior forebrain pathway，AFP）的主要输入来源，AFP是发声学习所必需的基底神经节相关回路。我们已经研究了活动的识别HVC神经元的斑胸草雀在唱歌。逆向激活被用来确定三类HVC细胞：神经元投射到前运动核RA，神经元投射到X区的AFP，和推定的HVC中间神经元。HVC中间神经元在整个歌曲中都是活跃的，并显示出紧张的活动模式。投射神经元表现出高度阶段性的定型放电模式。X投射（HVC（X））神经元每个基序爆发零到四次，而RA投射神经元的爆发极其稀疏--每个基序最多一次。HVC投射神经元的爆发被紧紧地锁定在歌曲中，并且通常具有< 1 ms的抖动。中间神经元的群体活动，而不是投射神经元，与音节模式显著相关。与HVC编码歌曲中的时间顺序而不是声音的想法一致，HVC中的声乐动力学和神经动力学发生在不同且不相关的时间尺度上。我们测试HVC（X）神经元是否在歌唱过程中对听觉敏感。我们记录了幼鸟在唱歌时这些神经元的活动，发现这些神经元的放电模式不会被扭曲的听觉反馈改变，这会破坏学习或导致已经学会的歌曲退化。
High vocal center (HVC) is part of the premotor pathway necessary for song production and is also a primary source of input to the anterior forebrain pathway (AFP), a basal ganglia-related circuit essential for vocal learning. We have examined the activity of identified HVC neurons of zebra finches during singing. Antidromic activation was used to identify three classes of HVC cells: neurons projecting to the premotor nucleus RA, neurons projecting to area X in the AFP, and putative HVC interneurons. HVC interneurons are active throughout the song and display tonic patterns of activity. Projection neurons exhibit highly phasic stereotyped firing patterns. X-projecting (HVC( X)) neurons burst zero to four times per motif, whereas RA-projecting neurons burst extremely sparsely-at most once per motif. The bursts of HVC projection neurons are tightly locked to the song and typically have a jitter of < 1 ms. Population activity of interneurons, but not projection neurons, was significantly correlated with syllable patterns. Consistent with the idea that HVC codes for the temporal order in the song rather than for sound, the vocal dynamics and neural dynamics in HVC occur on different and uncorrelated time scales. We test whether HVC(X) neurons are auditory sensitive during singing. We recorded the activity of these neurons in juvenile birds during singing and found that firing patterns of these neurons are not altered by distorted auditory feedback, which is known to disrupt learning or to cause degradation of song already learned.