Dopamine immunoreactivity in the central complex and lateral accessory lobe.

<p>A-L: Frontal sections. M-O: Horizontal sections. Dopamine immunoreactivity shown in magenta (A, D, G, J, M) and synapsin immunoreactivity in green (B, E, H, K, N). Corresponding merged images in C, F, I, L, O. <b>A-C</b>: Frontal sections through the central body (CB) and lateral accessory lobe (LAL). The upper and lower divisions of the central body (CBU and CBL, respectively) display intense dopamine immunoreactivity. Immunoreactive fibers innervate the dorsal and ventral shell of the lateral accessory lobe (DS and VS, respectively) and parts of the pedunculus (PED; arrowheads in A,C). A bundle of fibers connecting the central body to the lateral accessory lobe also exhibits dopamine immunoreactivity (arrows in A,C). <b>D-F</b>: Frontal sections through the anterior lip (ANL) innervated by dense dopamine-immunoreactive fibers. Labeled fibers are also seen in the superior medial protocerebral neuropil (SMP). <b>G-I</b>: Frontal sections through the central body and medial lobe (ML). Immunoreactive fibers are widely distributed in both structures, except for part of the medial lobe indicated by brackets in G. The immuno-negative region is flanked by a dense meshwork of dopamine-immunoreactive fibers. Double arrow in G indicates a plexus of immunoreactive processes in the posterior groove, originating from DP2 neurons. <b>J-L</b>: Frontal sections through the posterior portion of the central body. DP1 cell bodies (arrowheads) extend their axons ventrally, and a part of the noduli (NO) display dopamine immunoreactivity. <b>M-O</b>: Horizontal sections through the protocerebral bridge (PB). DP2 clusters (indicated by triangles) extend their axons anteriorly. Immunoreactive fibers bypass the protocerebral bridge, which lacks dopamine immunolabeling. D, dorsal; ON, ocelluar nerve; P, posterior. Scale bars = 100 μm.