title: Hydrostatic fluid pressure in the vestibular organ of the guinea pig.
abstract: Since inner ear hair cells are mechano-electric transducers the control of hydrostatic pressure in the inner ear is crucial. Most studies analyzing dynamics and regulation of inner ear hydrostatic pressure performed pressure measurements in the cochlea. The present study is the first one reporting about absolute hydrostatic pressure values in the labyrinth. Hydrostatic pressure of the endolymphatic system was recorded in all three semicircular canals. Mean pressure values were 4.06 cmH(2)O ± 0.61 in the posterior, 3.36 cmH(2)O ± 0.94 in the anterior and 3.85 cmH(2)O ± 1.38 in the lateral semicircular canal. Overall hydrostatic pressure in the vestibular organ was 3.76 cmH(2)O ± 0.36. Endolymphatic hydrostatic pressure in all three semicircular canals is the same (p = 0.310). With regard to known endolymphatic pressure values in the cochlea from past studies vestibular pressure values are comparable to cochlear values. Until now it is not known whether the reuniens duct and the Bast's valve which are the narrowest passages in the endolymphatic system are open or closed. Present data show that most likely the endolymphatic system is a functionally open entity.
authors: Department of Otorhinolaryngology and Head and Neck Surgery, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany. jpark@ukaachen.de
authors: Jonas J-H
authors: JJ
authors: Park
authors: Jahn J
authors: JJ
authors: Boeven
authors: Stefan
authors: S
authors: Vogel
authors: Steffen
authors: S
authors: Leonhardt
authors: Hero P
authors: HP
authors: Wit
authors: Martin
authors: M
authors: Westhofen
mesh_terms: D000818:Animals; D003051:Cochlea / Q000502:physiology; D018495:Fluid Shifts / Q000502:physiology*; D006168:Guinea Pigs; D057446:Hydrodynamics; D006874:Hydrostatic Pressure; D007761:Labyrinthine Fluids / Q000502:physiology*; D012016:Reference Values; D012665:Semicircular Canals / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000502:physiology*