Response profiles to amino acid odorants of olfactory glomeruli in larval Xenopus laevis
Response profiles to amino acid odorants of olfactory glomeruli in larval Xenopus laevis
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DOI：
10.1113/jphysiol.2007.130518
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发表时间：
2007-06-01
影响因子：
5.5
通讯作者：
Schild, Detlev
中科院分区：
文献类型：
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作者：
Manzini, Ivan;Brase, Christoph;Schild, Detlev
脊椎动物嗅球 (OB) 中的肾小球在解剖学上表现为离散模块，通过嗅觉受体神经元 (ORN) 的轴突接收来自嗅觉上皮 (OE) 的直接输入。最近确定并分析了非洲爪蟾幼虫中大量 ORN 对氨基酸 (AA) 的反应谱。在这里，我们报告了同一物种在同一发育阶段的鼻脑制剂中的 Ca2+ 成像实验。我们记录了 OB 中肾小球对 AA 的反应，并确定了单个肾小球对 AA 的反应概况。我们描述了 AA 反应性肾小球的一般特征，并将其对 AA 的反应概况与我们之前研究中获得的 ORN 的反应概况进行了比较。过去的大量研究要么集中在 OE 中的气味反应，要么集中在 OB 中气味引起的反应。然而，目前还缺乏对同一物种的两个阶段、ORN 和肾小球的气味诱导反应的彻底比较。本文报道的肾小球反应概况与之前获得的 ORN 反应概况显着不同，因为肾小球明显具有比 ORN 更窄的选择性概况。我们在嗅觉图谱发展的背景下讨论了肾小球和 ORN 的不同选择性特征的可能解释。
Glomeruli in the vertebrate olfactory bulb (OB) appear as anatomically discrete modules receiving direct input from the olfactory epithelium (OE) via axons of olfactory receptor neurons (ORNs). The response profiles with respect to amino acids (AAs) of a large number of ORNs in larval Xenopus laevis have been recently determined and analysed. Here we report on Ca2+ imaging experiments in a nose-brain preparation of the same species at the same developmental stages. We recorded responses to AAs of glomeruli in the OB and determined the response profiles to AAs of individual glomeruli. We describe the general features of AA-responsive glomeruli and compare their response profiles to AAs with those of ORNs obtained in our previous study. A large number of past studies have focused either on odorant responses in the OE or on odorant-induced responses in the OB. However, a thorough comparison of odorant-induced responses of both stages, ORNs and glomeruli of the same species is as yet lacking. The glomerular response profiles reported herein markedly differ from the previously obtained response profiles of ORNs in that glomeruli clearly have narrower selectivity profiles than ORNs. We discuss possible explanations for the different selectivity profiles of glomeruli and ORNs in the context of the development of the olfactory map.