NEURAL HETEROGENEITIES AND STIMULUS PROPERTIES AFFECT BURST CODING IN VIVO
NEURAL HETEROGENEITIES AND STIMULUS PROPERTIES AFFECT BURST CODING IN VIVO
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DOI：
10.1016/j.neuroscience.2010.03.012
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发表时间：
2010-06-16
期刊：
影响因子：
3.3
通讯作者：
Chacron, M. J.
中科院分区：
文献类型：
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作者：
Avila-Akerberg, O.;Krahe, R.;Chacron, M. J.
许多神经元倾向于发射称为脉冲的动作电位簇，随后是对感觉输入的静止反应。虽然在体外，爆发放电的机制通常被很好地理解，但这些爆发在体内产生对感觉输入的行为反应中的功能作用却不太清楚。弱电鱼电感觉侧线叶（ELL）内的锥体细胞为研究突发放电的编码特性提供了一个有吸引力的模型系统，因为电感觉回路的解剖和生理学已经得到了很好的理解，ELL锥体细胞的突发机制已经在体外得到了彻底的表征。我们研究了这些细胞在体内响应与行为相关的感觉输入的模拟而产生的脉冲的编码特性。我们发现锥体细胞群的异质性对宽带时变输入低频分量的突发编码有定量而非定性的影响。此外，空间局部刺激（例如，模仿猎物）比空间全局刺激（模仿特定相关刺激）更容易引发更多的爆发。我们还发现，突发属性（如每次突发的尖峰数量或突发期间的尖峰间隔）与刺激属性（如刺激幅度或斜率）之间存在微小但显著的相关性。这些相关性在量级上比在体外观察到的要弱得多。更令人惊讶的是，我们的结果表明，当我们使用预期会促进突发放电的低频刺激时，突发和刺激属性之间的相关性实际上在幅度上有所下降。我们认为这种差异是由于体内和体外条件下ELL锥体细胞爆发放电的差异。(c) 2010 ibro。Elsevier Ltd.出版。版权所有。
Many neurons tend to fire clusters of action potentials called bursts followed by quiescence in response to sensory input. While the mechanisms that underlie burst firing are generally well understood in vitro, the functional role of these bursts in generating behavioral responses to sensory input in vivo are less clear. Pyramidal cells within the electrosensory lateral line lobe (ELL) of weakly electric fish offer an attractive model system for studying the coding properties of burst firing, because the anatomy and physiology of the electrosensory circuitry are well understood, and the burst mechanism of ELL pyramidal cells has been thoroughly characterized in vitro. We investigated the coding properties of bursts generated by these cells in vivo in response to mimics of behaviorally relevant sensory input. We found that heterogeneities within the pyramidal cell population had quantitative but not qualitative effects on burst coding for the low frequency components of broadband time varying input. Moreover, spatially localized stimuli mimicking, for example, prey tended to elicit more bursts than spatially global stimuli mimicking conspecific-related stimuli. We also found small but significant correlations between burst attributes such as the number of spikes per burst or the interspike interval during the burst and stimulus attributes such as stimulus amplitude or slope. These correlations were much weaker in magnitude than those observed in vitro. More surprisingly, our results show that correlations between burst and stimulus attributes actually decreased in magnitude when we used low frequency stimuli that are expected to promote burst firing. We propose that this discrepancy is attributable to differences between ELL pyramidal cell burst firing under in vivo and in vitro conditions. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.