The cerebellar nucleo-olivary and olivocerebellar nuclear projections in the cat as studied with anterograde and retrograde transport in the same animal after implantation of crystalline WGA-HRP. III. The interposed nuclei.
The bidirectional connections between the inferior olive and the cerebellar nuclei were investigated by means of anterograde and retrograde transport after implantation of crystalline wheat germ agglutinin-horseradish peroxidase complex in the interposed nuclei. The projections from the interposed nuclei to the inferior olive show a detailed topical arrangement. The main projection from the anterior interposed nucleus reaches the rostral two thirds of the dorsal accessory olive, while the main projection from the posterior interposed nucleus reaches the rostral half of the medial accessory olive. The projections from the inferior olive to the interposed nuclei show a more widespread distribution and appear to be less precisely organized. Both interposed nuclei receive afferents from the medial and dorsal accessory olives, the dorsomedial cell column, nucleus beta and the dorsal cap. Our findings give evidence that the olivo-interposed and interposito-olivary projections are in part reciprocally organized. Our observations are discussed and related to previous investigations on the cerebello-olivary and olivocerebellar pathways. Some methodological comments are made. It appears from our results that anterograde transport in some of our cases has occurred only from a restricted part of the stained area at the implantation site.
D000818:Animals; D002415:Cats; D002529:Cerebellar Nuclei / Q000033:anatomy & histology*; D009434:Neural Pathways / Q000033:anatomy & histology; D009847:Olivary Nucleus / Q000033:anatomy & histology*