Reticulocerebellar projections to the anterior and posterior lobes of the rat cerebellum

By using retrograde double-labeling techniques, we analyzed the topography of projections from the lateral reticular nucleus (LRN) to the anterior and posterior lobes of the cerebellum, with the aim to investigate whether LRN projections to the two lobes come from different neurons or from branching axons of the same cells. We observed that about 4/5 of afferents the cereb ellar cortex come from the ipsilateral LRN and about 1/5 from the contralat eral nucleus. Furthermore, magnocellular division of LRN projects mainly to the anterior lobe, whereas parvicellular part primarily to the posterior l obe. The double-labelled cells were very numerous (about 1/3) and were loca ted throughout the LRN, with the higher incidence in the magnocellular divi sion and the lower in the subtrigeminal part. (C) 2001 Elsevier Science Ire land Ltd. All rights reserved.