Objective. To study the projections of individual subregions of the dorsal raphe nucleus (DRN) to functionally diverse areas of the basal ganglia in the dog brain. Materials and methods. A method based on the retrograde axonal transport of horseradish peroxidase (HRP) was used in 43 mongrel dogs given injections into functionally diverse areas of the basal ganglia to study the spatial organization of the projections from different parts of the DRN to these structures. At 48 h after perfusion of the brain, tetramethylbenzidine was used for the histochemical detection of HRP in DRN neurons in frontal serial sections of the brain and the numbers of labeled neurons in each area, as identified on serial frontal celloidin brain sections stained with toluidine, were counted under the microscope. Results. The spatial organization of projections to functionally diverse areas of the basal ganglia from individual functionally diverse parts of the DRN was studied in dogs using a method based on the retrograde axonal transport of HRP. The topographic characteristics of projection connections were identified, pointing to the possible segregated conduction of information from the dorsal part of the DRN, which has connections with limbic structures, i.e., limbic subareas of the corpus striatum. The overlapping of the terminal fields of neurons from all parts of the DRN receiving and sending functionally diverse information to the basal ganglia and structures connected to them seen in the entopeduncular nucleus, the ventral pallidum, the deep mesencephalic nucleus, and the medial part of the pedunculopontine nucleus of the tegmentum is evidence that this information may be integrated in these nuclei. The structural basis for information processing in the morphofunctional system of the basal ganglia was analyzed. Conclusions. Data are presented on the topographical organization of projections directed to functionally diverse areas of the basal ganglia from different parts of the DRN, providing evidence of the possible influences of different parts of the DRN on a wide spectrum of behavioral and physiological processes involving the basal ganglia. The connection system identified here is involved in conducting information and integrating it in the morphofunctional system of the basal ganglia and provides the structural basis for understanding the mechanisms of their functioning in health and disease.