Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, USA.
Nat Neurosci. 2010 Apr;13(4):439-49. doi: 10.1038/nn.2489. Epub 2010 Feb 7.
Local interneurons are essential in information processing by neural circuits. Here we present a comprehensive genetic, anatomical and electrophysiological analysis of local interneurons (LNs) in the Drosophila melanogaster antennal lobe, the first olfactory processing center in the brain. We found LNs to be diverse in their neurotransmitter profiles, connectivity and physiological properties. Analysis of >1,500 individual LNs revealed principal morphological classes characterized by coarsely stereotyped glomerular innervation patterns. Some of these morphological classes showed distinct physiological properties. However, the finer-scale connectivity of an individual LN varied considerably across brains, and there was notable physiological variability within each morphological or genetic class. Finally, LN innervation required interaction with olfactory receptor neurons during development, and some individual variability also likely reflected LN-LN interactions. Our results reveal an unexpected degree of complexity and individual variation in an invertebrate neural circuit, a result that creates challenges for solving the Drosophila connectome.
局部神经元在神经回路的信息处理中至关重要。在这里，我们对果蝇触角叶中的局部神经元（LN）进行了全面的遗传、解剖和电生理分析，触角叶是大脑中第一个嗅觉处理中心。我们发现 LN 在其神经递质谱、连接和生理特性方面存在多样性。对>1500 个单个 LN 的分析揭示了主要的形态学类别，其特征是粗略的规则化的肾小球支配模式。其中一些形态学类别表现出明显的生理特性。然而，单个 LN 的更精细的连接在不同的大脑中变化很大，并且在每个形态学或遗传类别中都存在显著的生理可变性。最后，LN 的支配在发育过程中需要与嗅觉受体神经元相互作用，并且一些个体变异性也可能反映了 LN-LN 相互作用。我们的结果揭示了一个意想不到的复杂程度和个体变化在一个无脊椎动物神经回路，这一结果为解决果蝇连接组带来了挑战。
