Bausenwein B, Dittrich A P, Fischbach K F
Institut für Biologie III, Freiburg, Federal Republic of Germany.
Cell Tissue Res. 1992 Jan;267(1):17-28. doi: 10.1007/BF00318687.
We present a quantitative evaluation of Golgi-impregnated columnar neurons in the optic lobe of wild-type Drosophila melanogaster. This analysis reveals the overall connectivity pattern between the 10 neuropil layers of the medulla and demonstrates the existence of at least three major visual pathways. Pathway 1 connects medulla layer M10 to the lobula plate. Input layers of this pathway are M1 and M5. Pathway 2 connects M9 to shallow layers of the lobula, which in turn are tightly linked to the lobula plate. This pathway gets major input via M2. Pathways 1 and 2 receive input from retinula cells R1-6, either via the lamina monopolar cell L1 (terminating in M1 and M5) or via L2 and T1 (terminating in M2). Neurons of these pathways typically have small dendritic fields. We discuss evidence that pathways 1 and 2 may play a major role in motion detection. Pathway 3 connects M8 to deep layers of the lobula. In M8 information converges that is derived either from M3 (pathway 3a) or from M4 and M6 (pathway 3b), layers that get their major input from L3 and R8 or L4 and R7, respectively. Some neurons of pathway 3 have large dendritic fields. We suggest that they may be involved in the computation of form and colour. Possible analogies to the organization of pathways in the visual system of vertebrates are discussed.
我们对野生型黑腹果蝇视叶中经高尔基染色的柱状神经元进行了定量评估。该分析揭示了髓质的10个神经毡层之间的整体连接模式，并证明至少存在三条主要的视觉通路。通路1将髓质层M10连接到小叶板。该通路的输入层是M1和M5。通路2将M9连接到小叶的浅层，而这些浅层又与小叶板紧密相连。该通路主要通过M2接收输入。通路1和通路2通过视杆细胞R1 - 6接收输入，要么通过层单极细胞L1（终止于M1和M5），要么通过L2和T1（终止于M2）。这些通路的神经元通常具有小的树突场。我们讨论了通路1和通路2可能在运动检测中起主要作用的证据。通路3将M8连接到小叶的深层。在M8中，来自M3（通路3a）或来自M4和M6（通路3b）的信息汇聚，M3和M4及M6层分别主要从L3和R8或L4和R7接收输入。通路3的一些神经元具有大的树突场。我们认为它们可能参与形状和颜色的计算。文中还讨论了与脊椎动物视觉系统中通路组织的可能类比。
