Subthreshold membrane responses underlying sparse spiking to natural vocal signals in auditory cortex.
Subthreshold membrane responses underlying sparse spiking to natural vocal signals in auditory cortex.
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DOI：
10.1111/ejn.12831
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发表时间：
2015-03
期刊：
影响因子：
--
通讯作者：
Gentner TQ
中科院分区：
文献类型：
--
作者：
Perks KE;Gentner TQ
自然声通信信号，如语音，通常是高维的，在多个时间尺度上具有广泛的共变光谱-时间特征。编码这些复杂信号的突触和网络机制在很大程度上是未知的。我们正在研究鸣禽听觉前脑的高级感觉区域的这些机制，在那里单个神经元对相同的歌曲表现出稀疏的、对象选择性的尖峰反应。利用全细胞体内膜片钳技术，研究了椋鸟尾侧中膜和尾侧内膜的阈下和峰值活动。我们发现亚阈值和峰值活动都是可靠的（即，同一首歌每次出现时都会引起相似的反应）和特定的（即对不同歌曲的反应是不同的）。然而，令人惊讶的是，亚阈值反应的可靠性和特异性都是一致的高，无论细胞何时出现尖峰，即使对于没有尖峰的歌曲刺激也是如此。我们得出的结论是，尽管有选择性和稀疏的尖峰反应，高级听觉皮层神经元处于连续的、非选择性的、刺激特异性的突触控制之下。为了研究局部网络抑制在突触控制中的作用，我们在药物阻断局部gaba -能传递的同时记录细胞外。这种操作调节了刺激驱动的尖峰的强度和可靠性，与局部抑制在调节网络活动的可靠性和单细胞阈下反应的刺激特异性中的作用一致。我们在基础计算的背景下讨论这些结果，这些计算可以产生稀疏的、刺激选择性的尖峰响应，以及分层池模型。
Natural acoustic communication signals, such as speech, are typically high-dimensional with a wide range of co-varying spectro-temporal features at multiple timescales. The synaptic and network mechanisms for encoding these complex signals are largely unknown. We are investigating these mechanisms in high-level sensory regions of the songbird auditory forebrain, where single neurons show sparse, object-selective spiking responses to conspecific songs. Using whole-cell in-vivo patch clamp techniques in the caudal mesopallium and the caudal nidopallium of starlings, we examine song-driven subthreshold and spiking activity. We find that both the subthreshold and the spiking activity are reliable (i.e., the same song drives a similar response each time it is presented) and specific (i.e. responses to different songs are distinct). Surprisingly, however, the reliability and specificity of the sub-threshold response was uniformly high regardless of when the cell spiked, even for song stimuli that drove no spikes. We conclude that despite a selective and sparse spiking response, high-level auditory cortical neurons are under continuous, non-selective, stimulus-specific synaptic control. To investigate the role of local network inhibition in this synaptic control, we then recorded extracellularly while pharmacologically blocking local GABA-ergic transmission. This manipulation modulated the strength and the reliability of stimulus-driven spiking, consistent with a role for local inhibition in regulating the reliability of network activity and the stimulus specificity of the subthreshold response in single cells. We discuss these results in the context of underlying computations that could generate sparse, stimulus-selective spiking responses, and models for hierarchical pooling.
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影响因子：
2.5
作者：
Kozlov, Andrei S.;Gentner, Timothy Q.
通讯作者：
Gentner, Timothy Q.
影响因子：
9.8
作者：
Hromádka T;Deweese MR;Zador AM
通讯作者：
Zador AM
DOI：
10.1073/pnas.092278099
发表时间：
2002-07-23
影响因子：
11.1
作者：
Blake, DT;Strata, F;Merzenich, MM
通讯作者：
Merzenich, MM
影响因子：
4.3
作者：
Helias M;Tetzlaff T;Diesmann M
通讯作者：
Diesmann M
影响因子：
5.3
作者：
Hsu, A;Woolley, SMN;Theunissen, FE
通讯作者：
Theunissen, FE