Figure 2. Schematic drawing of the cytoarchitecture of the rostral tract of the adult amphioxus nervous system. (A) Lateral view including the anterior vesicle, the intercalated region (anterior, intermediate, and posterior) and an anterior tract of the spinal cord (redrawn from Castro et al., 2015). (B) Dorsal view (redrawn from Nieuwenhuys, 1998). n1-n7, left (l) and right (r) branches of spinal nerves; ps, pigment spot of the frontal eye; Jc, Joseph cells; Rh1 and Rh2, first and second anterior Rohde cells respectively; nRh, Rohde nucleus; He, Hesse eyecups; Rc (yellow dots), Retzius cells; Ec (green dots), Edinger cells; vm (red dots), ventral motoneuron; v, cerebral ventricle; cc, central canal of the nerve cord; io, infundibular organ; lb, lamellar body; Hp, Hatschek pit.