Inhibitory interactions among olfactory glomeruli do not necessarily reflect spatial proximity.
Inhibitory interactions among olfactory glomeruli do not necessarily reflect spatial proximity.
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嗅觉肾小球之间的抑制性相互作用并不一定反映空间邻近性。
DOI：
10.1152/jn.90231.2008
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发表时间：
2008
影响因子：
2.5
通讯作者：
Hildebrand,JohnG
中科院分区：
文献类型：
--
作者：
Reisenman,CarolinaE;Heinbockel,Thomas;Hildebrand,JohnG
抑制性相互作用塑造了初级嗅觉中心输出神经元的活动，并促进了气味表征的对比度增强。然而，肾小球间连接的模式在很大程度上是未知的。为了测试是否接近的肾小球彼此之间的肾小球抑制相互作用相关，我们使用细胞内记录和染色的方法来记录与已知的嗅觉调谐在蛾Manducasexta的初级嗅觉中心的肾小球相关的投射（输出）神经元（PN）的反应。我们专注于Toroid I，雄性特异性大肾小球复合体（MGC）中的肾小球，专门用于同种雌性性信息素的两个关键成分之一，以及相邻的性同构肾小球35，对Z-3-己烯基乙酸酯（Z3-6：OAc）高度敏感。我们使用这两种气味剂来激活这些参考肾小球，并在其他肾小球中测试嗅觉激活的效果。我们发现Toroid-I PN不被G35的输入抑制，而G35 PN被Toroid-I PN的输入抑制。我们还记录了PNs arborizing在其他性同构的肾小球刺激性信息素和Z3-6：乙酸乙酯的反应。我们发现，抑制反应是不相关的接近MGC和G35：无论是遥远的和相邻的PN被抑制性信息素的刺激，其他一些人只受一种气味剂，而另一些既不。在女性特定肾小球附近记录的女性PN中获得了类似的结果。我们的研究结果表明，肾小球之间的抑制相互作用是广泛的，独立的空间接近。
Inhibitory interactions shape the activity of output neurons in primary olfactory centers and promote contrast enhancement of odor representations. Patterns of interglomerular connectivity, however, are largely unknown. To test whether the proximity of glomeruli to one another is correlated with interglomerular inhibitory interactions, we used intracellular recording and staining methods to record the responses of projection (output) neurons (PNs) associated with glomeruli of known olfactory tuning in the primary olfactory center of the mothManduca sexta. We focused on Toroid I, a glomerulus in the male-specific macroglomerular complex (MGC) specialized to one of the two key components of the conspecific females' sex pheromone, and the adjacent, sexually isomorphic glomerulus 35, which is highly sensitive to Z-3-hexenyl acetate (Z3-6:OAc). We used the two odorants to activate these reference glomeruli and tested the effects of olfactory activation in other glomeruli. We found that Toroid-I PNs were not inhibited by input to G35, whereas G35 PNs were inhibited by input to Toroid-I PNs. We also recorded the responses of PNs arborizing in other sexually isomorphic glomeruli to stimulation with the sex pheromone and Z3-6:OAc. We found that inhibitory responses were not related to proximity to the MGC and G35: both distant and adjacent PNs were inhibited by stimulation with the sex pheromone, some others were affected by only one odorant, and yet others by neither. Similar results were obtained in female PNs recorded in proximity to female-specific glomeruli. Our findings indicate that inhibitory interactions among glomeruli are widespread and independent of their spatial proximity.