Mapping of labeled climbing fibers and summarized topographic scheme of the olivocerebellar projection belonging to group IV. This group consisted of projections from the dorsal fold of the DAO (d-DAO), ventral fold of the DAO (v-DAO), and dorsomedial subnucleus of the PO (DM) to 2-//4-, b+//f+, b-//f-, 3+//e+, 3-//e1-, 4-//5-, and 5-//6-, and possibly to 3b+//e2+. A, Plots of labeled climbing fibers in nine injections terminating mainly in compartments 2-//4-, b+//f+, b-//f-, and 3+//e+. Two injections (green and light green) were spread to the d-DAO and v-DAO. B, Plots of labeled climbing fibers in four injections in the intermediate v-DAO, terminating in several compartments, including 3-//e1- (yellow). C, Plots of labeled climbing fibers in five injections in the medial v-DAO, terminating mainly in 4-//5- and also in caudal 5a-. D, Plots of labeled climbing fibers in four injections in the DM, terminating in 5-//6- and in caudal 5-. Labeled climbing fibers in 9 of 22 experiments were virtually aligned in a single narrow band, if a small number of outside climbing fibers can be ignored. E, Putative olivocerebellar topography within group III determined from the results shown in A and B.