title: Cytoarchitecture and saccular innervation of nucleus y in the mouse.
abstract: The cytoarchitecture and saccular innervation of the mouse nucleus y were investigated by using Golgi, Nissl, and myelin stains and anterograde axonal transport of horseradish peroxidase. Nucleus y was found to be a compact group of cells in a small fiber-free region dorsal to the restiform body. Qualitative and morphometric analyses showed that most (75%) of the nucleus y neurons could not be reliably subdivided into morphologic subgroups, but varied continuously in soma size (15-25 microns), shape (fusiform to stellate), and number of dendrites (two to four), and had sparsely branched dendrites with an average of 3 to 4 spines per 10 microns of length. Three groups of cells that were identified morphometrically accounted for 10% (type I: large stellate cells), 9% (type II: long-dendrite cells), and 6% (type III: elongated soma cells) of the y neurons. Vestibular nerve axons transporting horseradish peroxidase after injury at their origin in the saccular neuroepithelium were found to form a dense terminal meshwork that was virtually co-extensive with the cytoarchitectonic boundaries of nucleus y. Nucleus y was distinguished from the overlying infracerebellar nucleus on the basis of anatomical, cytoarchitectural, and hodological features.
mesh_terms: D000818:Animals; D002415:Cats; D005701:Galago; D008253:Macaca mulatta; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D012444:Saccule and Utricle / Q000294:innervation*; D013045:Species Specificity; D014725:Vestibular Nerve / Q000033:anatomy & histology*; D014726:Vestibular Nuclei / Q000033:anatomy & histology* / Q000166:cytology