Network organization of interstitial connective tissue cells in the human endolymphatic duct.
The human endolymphatic duct (ED) and sac of the inner ear have been suggested to control endolymph volume and pressure. However, the physiological mechanisms for these processes remain obscure. We investigated the organization of the periductal interstitial connective tissue cells and extracellular matrix (ECM) in four freshly fixed human EDs by transmission electron microscopy and by immunohistochemistry. The unique surgical material allowed a greatly improved structural and epitopic preservation of tissue. Periductal connective tissue cells formed frequent intercellular contacts and focally occurring electron-dense contacts to ECM structures, creating a complex tissue network. The connective tissue cells also formed contacts with the basal lamina of the ED epithelium and the bone matrix, connecting the ED with the surrounding bone of the vestibular aqueduct. The interstitial connective tissue cells were non-endothelial and non-smooth muscle fibroblastoid cells. We suggest that the ED tissue network forms a functional mechanical entity that takes part in the control of inner ear fluid pressure and endolymph resorption.
Hultgård-Ekwall
Anna-Karin H
AK
Department of Medical Biochemistry and Microbiology, University of Uppsala Biomedical Center, Box 582, SE-751 23 Uppsala, Sweden. Anna-Karin.Ekwall@imbim.uu.se
Couloigner
Vincent
V
Rubin
Kristofer
K
Rask-Andersen
Helge
H
D003239:Connective Tissue Cells / Q000378:metabolism / Q000648:ultrastructure*; D004711:Endolymphatic Duct / Q000378:metabolism / Q000648:ultrastructure*; D004848:Epithelium / Q000378:metabolism / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron / Q000379:methods