Long-range inhibition within the zebra finch song nucleus RA can coordinate the firing of multiple projection neurons
Long-range inhibition within the zebra finch song nucleus RA can coordinate the firing of multiple projection neurons
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DOI：
10.1152/jn.1999.81.6.3007
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发表时间：
1999-06-01
影响因子：
2.5
通讯作者：
Mooney, R
中科院分区：
文献类型：
--
作者：
Spiro, JE;Dalva, MB;Mooney, R
斑胸草雀前脑歌曲控制核RA（原始纹状体的鲁棒核）产生一个相位和时间精确的神经信号，驱动发声和呼吸运动神经元在唱歌。RA的输出在唱歌预测个别注意到，即使传入驱动RA从歌曲核HVC是更紧张，并预测歌曲音节，独立的特定注意到，包括音节。因此，RA的内在电路将HVc的神经活动转化为高度精确的前运动输出。为了了解RA的内在电路如何影响这种转变，我们使用脑切片中的细胞内记录来表征RA中间神经元和投射神经元。RA interneurons发射快速动作电位与陡峭的电流频率关系，并有小的胞体与薄的棘突，延伸到整个大部分的核;其精细的过程与谷氨酸脱羧酶（GAD）抗体标记的那些的相似性强烈表明，这些interneurons是GABA能的。电刺激显示，RA中间神经元接受兴奋性输入RA的传入，外侧大细胞核的前新纹状体（LMAN）和HVc，并从当地的轴突侧支RA投射神经元。为了映射RA中间神经元到RA投射神经元的功能连接，我们集中释放谷氨酸，揭示RA中的长距离抑制连接。因此，这些interneurons提供快速前馈和反馈抑制RA投射神经元，并可能有助于创建的爆发和停顿，RA输出的特点在唱歌的相位模式。此外，选择性地激活抑制性网络相位锁定发射，否则不连接的投射神经元对：这表明，局部抑制可以协调RA输出在唱歌。
The zebra finch forebrain song control nucleus RA (robust nucleus of the archistriatum) generates a phasic and temporally precise neural signal that drives vocal and respiratory motoneurons during singing. RA's output during singing predicts individual notes, even though afferent drive to RA from the song nucleus HVc is more tonic, and predicts song syllables, independent of the particular notes that comprise the syllable. Therefore RA's intrinsic circuitry transforms neural activity from HVc into a highly precise premotor output. To understand how RA's intrinsic circuitry effects this transformation, we characterized RA interneurons and projection neurons using intracellular recordings in brain slices. RA interneurons fired fast action potentials with steep current-frequency relationships and had small somata with thin aspinous processes that extended throughout large portions of the nucleus; the similarity of their fine processes to those labeled with a glutamic acid decarboxylase (GAD) antibody strongly suggests that these interneurons are GABAergic. Electrical stimulation revealed that RA interneurons receive excitatory inputs from RA's afferents, the lateral magnocellular nucleus of the anterior neostriatum (LMAN) and HVc, and from local axon collaterals of RA projection neurons. To map the functional connections that RA interneurons make onto RA projection neurons, we focally uncaged glutamate, revealing long-range inhibitory connections in RA. Thus these interneurons provide fast feed-forward and feedback inhibition to RA projection neurons and could help create the phasic pattern of bursts and pauses that characterizes RA output during singing. Furthermore, selectively activating the inhibitory network phase locks the firing of otherwise unconnected pairs of projection neurons: suggesting that local inhibition could coordinate RA output during singing.