The cerebellar projection from locus coeruleus as studied with retrograde transport of horseradish peroxidase in the cat

Summary The cerebellar afferent projection from locus coeruleus has been studied in the cat by means of retrograde axonal transport of horseradish peroxidase. Labelled cells are present bilaterally in locus coeruleus only following injections in the cerebellar vermis (especially its anterior and posterior parts), the ventral paraflocculus and the flocculus. The labelled cells are restricted to the caudal half of the nucleus.A few labelled cells are also present in locus coeruleus following injections in the fastigial nucleus, and in nucleus interpositus anterior. The findings are discussed in relation to other studies on the efferent and afferent connections of the locus coeruleus.On leave from the Laboratory of Neurobiology and Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand, under the Fellowship Program of the Norwegian Agency for International Development (NORAD)