[The organization of the projections of the rostromedial tegmental nucleus to the striatum in canine brain].

Method of retrograde axonal transport of horseradish peroxidase and fluorochromes was used to study the organization of the projections of the rostromedial tegmental nucleus (RMTN) to the functionally diverse regions of striatal structures of dog brain (n=26). It was found that the projection fibers of the neurons of RMTN limbic medial part were directed only to the ventral limbic segments of the nucleus caudatus, the putamen and the nucleus accumbens. However, the convergence of the projection fibers originating from the neurons of functionally different RMTN parts was observed in the majority of the segments of the striatal structures. Thus, the projection fibers of the motor lateral and the limbic medial RMTN parts were directed to the motor dorso-lateral segment of the caudate nucleus and also to the striatal segments, which were innervated by the fibers from the neurons of functionally diverse structures (ventro-lateral segment of the caudate nucleus and the lateral segment of the nucleus accumbens). Possible pathways conducting functionally different information and its integration in the investigated projection systems are discussed.