The mesencephalic nucleus of the trigeminus in man

If the mesencephalic trigeminal nucleus were built up uniquely from unipolar, big cells, its extension in man would be greater than hitherto admitted: on both sides of the mesencephalic tract, mingled with cells of the locus ceruleus, and in the superior medullary velum. In all sites, beside unipolar cells there are always a few bi- and multipolar cells in the constitution of the mesencephalic trigeminal nucleus. The big cells of this nucleus are not perfectly spherical, as often suggested, but always somewhat flattened. Many synaptic boutons lie on their perikarion and their unique process.