A projection from the raphe nuclei to the lateral reticular nucleus in the cat

By means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex afferent fibres to the lateral reticular nucleus from the raphe nuclei were demonstrated in the cat. The projection is bilateral and has its main origin in nucleus raphe pallidus and magnus, but there appear to be contributions also from nucleus raphe obscurus, dorsalis and linearis rostralis.