Distribution of C1 and C2 sNPF receptor immunolabeled clusters observed in the anterior queen brain. A: The position of cell clusters C1 and C2 in the anterior side of the brain are shown in a schematic. Confocal images obtained with single red channel for receptor signal (D, G, H, J and L) or red merged with cyan (DAPI nuclear stain) (B, C, F, I and K) are shown. B: Single image of cluster C1 (arrow) located in the superior medial protocerebrum (smP). V: vertical lobe of the mushroom body. C and D: Higher magnification images of B show that three cells (arrows) are detected with sNPF receptor antibodies. mCa: median calyces. E-L: Cluster C2 (~25 cells) is located near the lateral calyces (lCa) of the mushroom bodies in the superior protocerebrum. The cluster C7 closer to the posterior side of the brain (F and G, thin arrow), seen faintly through the section, will be described in figure 5. E: A schematic showing the relative position of C2 cells near the lCa. F and G: The cluster C2 cells surround the anterior half-side of the lateral pedunculi (lPed). H: Higher magnification image of G. I-L: Out of 25 cells in cluster C2, seven cells (arrowheads) located closer to the anterior surface of the lCa are likely lateral neurosecretory cells (arrowheads). Confocal stacked images thickness: 21.42 μm for C and D; 33.66 μm for F-H; 9.24 μm for K and L. M-P: Whole mount image obtained with Axioimager A1 microscope.