Figure 3.

Optic neuropils and the lateral protocerebrum. (A) Overview of the brain from posterior and dorsal view of the anterior part of the VNC. The dotted line indicates the change of orientation between brain and nerve cord. The optN are supplied by the R by oNv. Two commissures connect the oc; an anterior vC, and the posterior MdC out of which the MdNv emerge. (B) Posterior view of the optN (B′) Magnification of connection between La and Me, the oCh. (B″) Magnification of connection between Me and Lo. The connectivity remains unresolved, thus the presumptive iCh is labeled with “?.” The Lo is accompanied by a small loP neuropil. (C) The lPC in different section planes, center (C) and anterior end (C′). The lPC is innervated by the PNT, giving off a branch innervating the HE (asterisk), the remainder proceeds into the MT (double asterisk). The PT connects optN and MT with the mPC. (C′) The HE is innervated by neurons located in three bulb-like clusters (5) anterodorsal to the neuropil. (D) The HE is heavily innervated by 5HTir neurons located in cluster (5′), giving of fine branches into the deeper layers and MT.