Odorant-evoked nitric oxide signals in the antennal lobe of Manduca sexta
Odorant-evoked nitric oxide signals in the antennal lobe of Manduca sexta
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DOI：
10.1523/jneurosci.0710-04.2004
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发表时间：
2004-07-07
影响因子：
5.3
通讯作者：
Nighorn, A
中科院分区：
文献类型：
--
作者：
Collmann, C;Carlsson, MA;Nighorn, A
气体信号分子一氧化氮(NO)可以影响许多不同系统中神经元和神经网络的活动。在大多数生物的嗅觉系统的初级突触神经束(昆虫的触角叶和脊椎动物的嗅球)中，一氧化氮合酶(NOS)的强烈表达，以及这些神经髓中嗅球独特的球形几何形状，导致了NO信号在处理嗅觉信息中的重要作用。然而，没有直接证据表明嗅觉小球中没有信号产生。我们用免疫细胞化学和实时光学成像技术，用不敏感的荧光标记物二氨基荧光素二乙酸酯，研究了六纹夜蛾触角小叶中NO的产生。我们证实一氧化氮合酶在嗅觉感受器神经元投射到所有肾小球的轴突中表达。突触后触角叶神经元包括投射神经元、少量GABA免疫反应神经元和5-羟色胺免疫反应神经元，在突触后触角叶神经元中发现了可溶鸟酰环化酶。我们发现气味刺激没有唤起可重现的、空间聚焦的信号。不同的气味会在空间上引发不同的NO生成模式。信息素和植物气味浓度的增加导致了峰值信号强度的增加。植物气味浓度的增加也引起了信号区的急剧增加。这些实验结果清楚地表明，气味刺激可以在嗅觉系统中引起NO的产生。产生的NO信号可能在处理嗅觉信息方面发挥重要作用。
The gaseous signaling molecule nitric oxide ( NO) can affect the activities of neurons and neural networks in many different systems. The strong expression of NO synthase ( NOS) in the primary synaptic neuropil ( the antennal lobe in insects and the olfactory bulb in vertebrates) of the olfactory system of most organisms, and the unique spheroidal geometry of olfactory glomeruli in those neuropils, have led to suggestions that NO signaling is important for processing olfactory information. No direct evidence exists, however, that NO signals are produced in olfactory glomeruli. We investigated the production of NO in the antennal lobe of the moth, Manduca sexta, by using immunocytochemistry and real-time optical imaging with a NO-sensitive fluorescent marker, diaminofluorescein diacetate. We confirmed that NOS was expressed in the axons of olfactory receptor neurons projecting to all glomeruli. Soluble guanylyl cyclase, the best characterized target of NO, was found in a subset of postsynaptic antennal lobe neurons that included projection neurons, a small number of GABA-immunoreactive neurons, and a serotonin-immunoreactive neuron. We found that odorant stimulation evoked NO signals that were reproducible and spatially focused. Different odorants evoked spatially distinct patterns of NO production. Increased concentrations of pheromone and plant odorants caused increases in peak signal intensity. Increased concentrations of plant odorants also evoked a dramatic increase in signal area. The results of these experiments show clearly that odorant stimulation can evoke NO production in the olfactory system. The NO signals produced are likely to play an important role in processing olfactory information.