title: Osmolar changes and neural activity in frog vestibular organs.
abstract: The effects of hypotonic and hypertonic solutions (the normal value was 240 mOsm) on posterior canal resting and evoked discharge were studied in isolated labyrinth preparations. Hypotonic solutions (60-180 mOsm) were obtained by reducing the perilymphatic NaCl content. Hypertonic solutions (300-420 mOsm) were obtained by adding to normal perilymphatic solutions suitable amounts of NaCl, glucose, sucrose, glycerol, mannitol and urea. The results demonstrated that any kind of receptor activity was inhibited by hypotonic solutions. On the contrary, hypertonic solutions produced different effects on resting and evoked activity. The resting discharge was, with the exception of urea, constantly increased whereas the evoked responses were constantly decreased by all the hypertonic solutions tested. The possible effects of media with changed osmolarity in Meniere's patients is also discussed.
authors.affiliation: Institute of General Physiology, University of Pavia, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Zucca
authors.forename: A
authors.initials: A
authors.lastname: Maracci
authors.forename: V
authors.initials: V
authors.lastname: Milesi
authors.forename: M
authors.initials: M
authors.lastname: Trimarchi
authors.forename: E
authors.initials: E
authors.lastname: Mira
authors.forename: M
authors.initials: M
authors.lastname: Manfrin
authors.forename: S
authors.initials: S
authors.lastname: Quaglieri
authors.forename: P
authors.initials: P
authors.lastname: Valli
mesh_terms: D000818:Animals; D046508:Culture Techniques; D018159:Endolymphatic Hydrops / Q000378:metabolism; D006982:Hypertonic Solutions / Q000493:pharmacokinetics / Q000494:pharmacology; D007038:Hypotonic Solutions / Q000493:pharmacokinetics / Q000494:pharmacology; D009431:Neural Conduction / Q000187:drug effects*; D009994:Osmolar Concentration; D010498:Perilymph / Q000187:drug effects; D011898:Ranidae; D014722:Vestibule, Labyrinth / Q000187:drug effects*
chemical_list: D006982:Hypertonic Solutions; D007038:Hypotonic Solutions