The vestibular nuclei in the domestic hen (Gallus domesticus). I. Normal anatomy.

The topography and the cyto- and fiber architecture of the vestibular nuclear complex in the domestic hen are described as seen in transverse and horizontal thionine and myelin impregnated section. The subdivision of the nuclear complex arrived at from these studies is discussed the light of some experimental studies of the fiber connection of the vestibular nuclei in birds and compared with the well known organization of the vestibular nuclei in mammals. Six main vestibular nuclei are identified, the superior nucleus, the nucleus Deiters ventralis, the nucleus Deiters dorsalis, the tangential nucleus, the medial nucleus and the descending nucleus. In addition two cell groups (the cell group A and B) lying in close relation to the other nuclei are described and considered as parts of the vestibular complex. The map of the vestibular complex arrived at is largely in agreement with the maps presented by most earlier authors on other species. Furthermore, it appears that the organization of the vestibular complex in birds is more similar to the organization of the complex in mammals than hitherto recognized.