Sachse Silke, Galizia C Giovanni
Institut für Biologie - Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 28-30, 14195 Berlin, Germany.
Eur J Neurosci. 2003 Oct;18(8):2119-32. doi: 10.1046/j.1460-9568.2003.02931.x.
We investigated strategies involved in odour intensity coding by the primary olfactory centre of insects, the antennal lobe (AL), the structural and functional analogue of the olfactory bulb. Using calcium imaging in the honeybee, we simultaneously measured the projection neuron output responses and a compound signal dominated by receptor neuron input in identified olfactory glomeruli to odours spanning seven log units of concentration. A comparison of the two processing levels indicates that the intercellular computation within the AL modulates and contrast-enhances the primary olfactory signals. As a result the AL network optimizes the olfactory code: odour representation is improved at lower concentrations, the relative activity of olfactory glomeruli allows encoding odour quality over up to four log-unit concentrations, and odour-intensity is reliably represented in the overall excitation across AL.
我们研究了昆虫的主要嗅觉中枢触角叶（AL）（嗅觉球的结构和功能类似物）对气味强度进行编码所涉及的策略。通过对蜜蜂进行钙成像，我们同时测量了投射神经元的输出反应以及在已识别的嗅觉小球中由受体神经元输入主导的复合信号对浓度跨越七个对数单位的气味的反应。对这两个处理水平的比较表明，AL内的细胞间计算对初级嗅觉信号进行调节和对比度增强。结果，AL网络优化了嗅觉编码：在较低浓度下气味表征得到改善，嗅觉小球的相对活性允许在高达四个对数单位浓度范围内编码气味质量，并且气味强度在整个AL的总体兴奋中得到可靠表征。
