Excitatory local circuits and their implications for olfactory processing in the fly antennal lobe
Excitatory local circuits and their implications for olfactory processing in the fly antennal lobe
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DOI：
10.1016/j.cell.2006.12.034
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发表时间：
2007-02-09
期刊：
影响因子：
64.5
通讯作者：
Miesenbock, Gero
中科院分区：
文献类型：
--
作者：
Shang, Yuhua;Claridge-Chang, Adam;Miesenbock, Gero
关于触角叶（相当于昆虫的嗅球）的回路如何将嗅觉受体神经元（ORN）的输入转化为投射神经元（PN）的输出，存在不同的观点。ORN和PN之间的突触连接是一对一的，然而PN比ORN更广泛地适应气味。这种感受范围差异的基础仍然未知。分析缺乏ORN输入一个肾小球的果蝇突变体，我们发现，一些明显的复杂性，在触角叶的输出产生横向，肾小球间的PN的兴奋。我们描述了一个以前身份不明的人口胆碱能神经元（LN）与多肾小球过程。这些兴奋性LN广泛地响应气味，但在其突触输出中表现出很少的肾小球特异性，这表明PN是由肾小球特异性ORN传入和弥漫性LN兴奋的组合驱动的。横向激励可以增强PN信号，并以类似于随机共振的机制增强它们向三阶神经元的传输。
Conflicting views exist of how circuits of the antennal lobe, the insect equivalent of the olfactory bulb, translate input from olfactory receptor neurons (ORNs) into projection-neuron (PN) output. Synaptic connections between ORNs and PNs are one-to-one, yet PNs are more broadly tuned to odors than ORNs. The basis for this difference in receptive range remains unknown. Analyzing a Drosophila mutant lacking ORN input to one glomerulus, we show that some of the apparent complexity in the antennal lobe's output arises from lateral, inter-glomerular excitation of PNs. We describe a previously unidentified population of cholinergic local neurons (LNs) with multiglomerular processes. These excitatory LNs respond broadly to odors but exhibit little glomerular specificity in their synaptic output, suggesting that PNs are driven by a combination of glomerulus-specific ORN afferents and diffuse LN excitation. Lateral excitation may boost PN signals and enhance their transmission to third-order neurons in a mechanism akin to stochastic resonance.