Figure 1.

Central projections from sensilla coeloconica. (A) 3D reconstruction of the major neuropils of a brain of Atta vollenweideri (courtesy of C. Kelber). AL, antennal lobe; CC, central complex; MB, mushroom bodies; OL, optic lobes; PB, protocerebrum. (B) Projection view of a confocal image stack. The three receptor neuron axons of a single sensillum coeloconicum (Sc) terminate each in a single glomerulus, and all three glomeruli are located in the dorsal part of the antennal lobe (two lateral glomeruli [Sc-L1 and Sc-L2] and a medial one [Sc-M]). (C) 3D reconstruction of the receptor neurons and the glomeruli innervated by the Sc of the specimen shown in Figure 1B. All three axons (diameter 1–1.4 μm, n = 6) establish extensive arborizations within their target glomeruli (for the green axon only arborizations are shown because a semi-automatic reconstruction was not possible). (D) Double-staining of a single Sc (green) and various hair sensilla (magenta) show no overlap in the three target glomeruli (inset picture illustrates the orientation of the investigated antennal lobe by using the exemplary brain shown in (A). D, dorsal; L, lateral; M, medial; V, ventral; Sc-L, lateral target glomeruli; Sc-M, medial target glomerulus.