Masante-Roca Ingwild, Gadenne Christophe, Anton Sylvia
Institut National de la Recherche Agronomique, Unité Mixte de Recherche en Santé Végétale, Centre de Recherche de Bordeaux, BP81, 33883 Villenave d'Ornon Cedex, France.
J Exp Biol. 2005 Mar;208(Pt 6):1147-59. doi: 10.1242/jeb.01508.
Spatiotemporal odour coding is thought to be linked closely with the specific glomerular anatomy of the primary olfactory centre. In most insects the number of the glomeruli within the antennal lobe is limited to fewer than 100, allowing their individual identification. In the grapevine moth, Lobesia botrana, a map of the antennal lobe glomeruli was reconstructed three-dimensionally, by comparing three different brains in males and females. The map of the antennal lobe of females served then as a basis to identify glomeruli containing dendritic arborisations of 14 physiologically characterised projection neurons. Projection neurons responding to the same plant compound did not always arborise in the same glomerulus and some neurons arborising in the same glomerulus responded to different compounds. Different zones of target glomeruli were, however, identified when pooling all neurons responding to one of two different compounds respectively (alpha-farnesene and nonatriene). All identified glomeruli of specifically responding projection neurons were situated close to the anterior surface of the antennal lobe. One broadly responding projection neuron arborised in a more posteriorly situated glomerulus. A local interneuron responding to only one compound was arborising densely in a neighbouring glomerulus and had sparse branches in all other glomeruli. These results are discussed with respect to plant odour processing and structure-function relations in antennal lobe neurons. The 3D AL atlas will, in the future, also be used to obtain a better understanding of coding mechanisms of grapevine odours in this pest insect.
时空气味编码被认为与初级嗅觉中枢的特定嗅小球解剖结构密切相关。在大多数昆虫中，触角叶内的嗅小球数量限制在100个以内，这使得它们能够被逐个识别。在葡萄小卷蛾（Lobesia botrana）中，通过比较雄性和雌性的三个不同大脑，三维重建了触角叶嗅小球图谱。雌性触角叶图谱随后作为识别包含14个生理特征化投射神经元树突分支的嗅小球的基础。对同一植物化合物做出反应的投射神经元并不总是在同一个嗅小球中形成树突分支，并且一些在同一个嗅小球中形成树突分支的神经元对不同的化合物做出反应。然而，当分别汇总对两种不同化合物（α-法尼烯和壬三烯）之一做出反应的所有神经元时，确定了目标嗅小球的不同区域。所有已识别的对特定化合物做出反应的投射神经元的嗅小球都位于触角叶的前表面附近。一个广泛做出反应的投射神经元在更靠后的嗅小球中形成树突分支。一个仅对一种化合物做出反应的局部中间神经元在相邻的嗅小球中密集地形成树突分支，而在所有其他嗅小球中具有稀疏的分支。结合植物气味处理以及触角叶神经元的结构-功能关系对这些结果进行了讨论。未来，这个三维触角叶图谱还将用于更好地理解这种害虫对葡萄气味的编码机制。
