The morphology of the cerebellar nuclei of Galago and Tupaia

The cerebellar nuclei of the lesser bushbaby (Galago senegalensis) and the tree shrew (Tupaia glis) were studied. The cerebellar nuclear grey of Galago is divisible into a medial nucleus, a nucleus interpositus anterior, a nucleus interpositus posterior, and a lateral nucleus. The lateral nucleus is slightly concave medially suggestive of a primitive hilus. The interpositus nucleus is divided into anterior and posterior portions by a delicate lamina of fibers. The medial cerebellar nucleus is an irregular mass of cells located dorsal to the fourth ventricle. The cerebellar nuclear grey of Tupaia is also divisible into a medial nucleus, a nucleus interpositus anterior, a nucleus interpositus posterior, and a lateral cerebellar nucleus. The medial cerebellar nucleus is located dorsal to the fourth ventricle. The nucleus interpositus anterior and nucleus interpositus posterior are joined together and with the lateral nucleus in the caudo-ventral region. The NIA and NIP have an anterior-posterior relationship to each other and the lateral nucleus has no apparent undulations suggestive of early sacculations. The configuration of the cerebellar nuclei of Tupaia more closely resembles the more primitive patterns of the rat, hedgehog, and mole than those of Galago or other primates.