Dynamics of inner ear pressure release, measured with a double-barreled micropipette in the guinea pig.
The inner ear fluid pressure was measured in scala media of the guinea pig through one barrel of a double-barreled micropipette after a sudden volume increase or decrease, caused by injection or withdrawal of artificial endolymph through the other barrel. During injection or withdrawal, the inner ear pressure changed in the order of 1-10 cm water, but it returned to its initial value within a few seconds. The time constant for the pressure recovery depended on the flow direction. It was on average 1.1 s after a short overpressure and 2.8 s after underpressure. The obtained results could be fitted with a simple physical model, when it was assumed that inner ear pressure recovery is a non-linear process, governed by a pressure-dependent flow resistance and/or membrane compliance.
Department of Otorhinolaryngology, University Hospital Groningen, The Netherlands. h.p.wit@med.rug.nl
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D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D007758:Ear, Inner / Q000502:physiology*; D004594:Electrophysiology; D004710:Endolymph / Q000502:physiology; D005260:Female; D006168:Guinea Pigs; D007267:Injections; D008954:Models, Biological; D011312:Pressure; D013997:Time Factors