Detailed Characterization of Local Field Potential Oscillations and Their Relationship to Spike Timing in the Antennal Lobe of the Moth Manduca sexta.
Detailed Characterization of Local Field Potential Oscillations and Their Relationship to Spike Timing in the Antennal Lobe of the Moth Manduca sexta.
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DOI：
10.3389/fneng.2011.00012
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Staudacher EM
中科院分区：
文献类型：
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作者：
Daly KC;Galán RF;Peters OJ;Staudacher EM
气味识别编码的瞬时振荡模型试图解释如何区分输入初级嗅觉网络的空间重叠模式的气味。该模型提供了几个关于网络振荡的分布式性质以及它们如何控制尖峰时间的可测试预测。为了验证这些预测，在六色蛾触角叶(AL)内放置了16个通道电极阵列。在自发活动期间和在气味面板的重复呈现时，进行单一的尖峰和多部位局部场电位(LFP)记录。我们量化了振荡频率、LFP记录位置之间的交叉相关性以及尖峰-LFP相位关系。我们发现，在Manduca中，气味驱动的AL振荡是从∼100到30 Hz的频率调制(FM)；这与气味和刺激持续时间有关。FM振荡反应局限于一个或两个记录点，提示有局部的(可能是肾小球的)非分布性来源。LFP互相关进一步表明，只存在一个很小的(r <； 0.05)分布和振荡分量。交叉谱密度分析表明，这些弱分布振荡的频率与状态有关(自发活动 = 为25-55 Hz；气味驱动 = 为55-85 Hz)。令人惊讶的是，向量强度分析表明，自发活动中对LFP的单位相位锁定最强，而在反应中显著下降。应用GABAA受体拮抗剂荷包牡丹碱显著降低气味驱动的分布式振荡活动的频率含量。荷包牡丹碱在总体上显著减少了峰时相锁定，但在自发活动中普遍存在的增加时相锁定的模式仍然存在。总之，这些结果表明，对于Manduca来说，振荡作为一种刺激中介的棘波同步机制表现不佳，因此与瞬时振荡模型不一致。
The transient oscillatory model of odor identity encoding seeks to explain how odorants with spatially overlapped patterns of input into primary olfactory networks can be discriminated. This model provides several testable predictions about the distributed nature of network oscillations and how they control spike timing. To test these predictions, 16 channel electrode arrays were placed within the antennal lobe (AL) of the moth Manduca sexta. Unitary spiking and multi site local field potential (LFP) recordings were made during spontaneous activity and in response to repeated presentations of an odor panel. We quantified oscillatory frequency, cross correlations between LFP recording sites, and spike–LFP phase relationships. We show that odor-driven AL oscillations in Manduca are frequency modulating (FM) from ∼100 to 30 Hz; this was odorant and stimulus duration dependent. FM oscillatory responses were localized to one or two recording sites suggesting a localized (perhaps glomerular) not distributed source. LFP cross correlations further demonstrated that only a small (r < 0.05) distributed and oscillatory component was present. Cross spectral density analysis demonstrated the frequency of these weakly distributed oscillations was state dependent (spontaneous activity = 25–55 Hz; odor-driven = 55–85 Hz). Surprisingly, vector strength analysis indicated that unitary phase locking of spikes to the LFP was strongest during spontaneous activity and dropped significantly during responses. Application of bicuculline, a GABAA receptor antagonist, significantly lowered the frequency content of odor-driven distributed oscillatory activity. Bicuculline significantly reduced spike phase locking generally, but the ubiquitous pattern of increased phase locking during spontaneous activity persisted. Collectively, these results indicate that oscillations perform poorly as a stimulus-mediated spike synchronizing mechanism for Manduca and hence are incongruent with the transient oscillatory model.