FIBER PROJECTIONS FROM THE NUCLEI OF THE TRIGEMINAL NERVE TO THE CEREBELLAR CORTEX OF THE RAT——A STUDY WITH THE HRP METHOD / 解剖学报

ABSTRACT

The trigemino-cerebellar projections of rats were studied by introducing HRP microelectrophoretically into various areas of the cerebellar cortex. The results indicate that the following parts of the cerebellum receive bilateral (mostly ipsilateral) trigeminal projections, namely, the simple lobule, the crusa Ⅰ and Ⅱ, the paramedian lobuIe, the dorsal paraflocculus, the lateral part of the lobule Ⅷ and the vermal cortex of the lobules Ⅵ～Ⅸ.Fibers from the interpolar subnucleus and the principal sensory nucleus of the trigeminal nerve project to all of the above mentioned areas.The caudal subnucleus projects to the crus Ⅰ, the paramedian lobule, the dorsal paraflocculus, the lateral part of the lobule Ⅷ and the vermal cortex of the lobules Ⅵ～Ⅸ.The oral subnucleus gives its projections to the crus Ⅱ, the paramedian lobule, the lateral part of the lobule Ⅷ and the vermal cortex of the lobules Ⅶ～Ⅸ.The mesencephalic nucleus of the trigeminal nerve sends fibers to the crura Ⅰ and Ⅱ, the paramedian lobule, the lateral part of the lobule Ⅷ and the vermal cortex of lobules Ⅶ～Ⅸ.A few labeled neurons were found in the motor nucleus of the trigeminal nerve; while in the region ventro-lateral to the motor nucleus, in the root of the trigeminal nerve and in areas adjacent to it large amount of labeled cells were seen in all the cases studied.Unexpectedly, several labeled neurons were seen in a semilunar ganglion of the trigeminal nerve.