Cerebellar nuclei subdivision

The subdivision of Weidenreich-Ogawa received strong support from the localization of the fibers in the superior cerebellar peduncle. A small medial and a large lateral portion can be distinguished in this pathway in most mammals at its exit from the central nuclei (see in Fig. 102). Experiments in cat (Verhaart, 1956 Voogd, 1964) and rat (Haroian et ah, 1981) have shown that the medial part of the superior cerebellar peduncle takes its origin from the nuclei of the caudomedial group, mainly from the ipsilateral posterior interposed nucleus, and the lateral portion from the ipsilateral anterior interposed and lateral cerebellar nucleus. 

The zonal organization of the efferent connections of the caudal vermis in the rabbit is quite complex, with discrete zones in the lobules IX and X projecting to the fastigial, descending, superior and medial vestibular nuclei, and lateral zones connected to the interposed and different subdivisions of the lateral cerebellar nucleus (van Rossum,... 

Fig. 152. Diagrams showing the topographic pattern of the projections from the various mediolateral levels of the tuber vermis (lobule VII) and the paramedian lobule to the cerebellar nuclear complex in the rat. A. Schematic diagram of the posterior surface of the cerebellum and subdivision of the tuber vermis and paramedian lobule, based on the topography of their projections. B. Schematic sagittal diagrams of the nuclear complex showing the terminal fields which receive projections from the individual subdivisions of the tuber vermis and paramedian lobule. AIN = anterior interposed nucleus cm = caudomedial sub-division of the medial nucleus Cop. pyr = copula pyramidis DLH = dorsolateral hump DLP = dorsolateral protuberance of the medial nucleus LN = lateral cerebellar nucleus LVN = lateral vestibular nucleus m = medial nucleus PIN = posterior interposed nucleus Pml = paramedian lobule. Umetani (1989).

Fig. 164. The nucleo-olivary projection in the rat. Data from Ruigrok and Voogd (1990). Upper and lower block diagrams represent the cerebellar and vestibular nuclei, and the subdivisions of the inferior olive respectively. According to Ruigrok and Voogd (1990) the cerebellar nuclei and their olivary target nuclei can be considered as a continuum, stretching from the rostral medial cerebellar nucleus, projecting to caudal MAO, to the lateral vestibular nucleus, projecting to the dorsal fold of the DAO. DL = dorsolateral protuberance of the medial cerebellar nucleus DMC = dorsomedial cell column IntA = anterior interposed nucleus IntDL = dorsolateral hump IntP = posterior interposed nucleus lOD = dorsal accessory olive lODM = dorsomedial cell column lOM = medial accessory olive lOP = principal olive Lat = lateral cerebellar nucleus LVe = lateral vestibular nucleus Med = medial cerebellar nucleus VL = ventrolateral outgrowth.

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