Abstract
Hydrostatic pressure in the endolymph and perilymph was measured by a servo-controlled micropipette system in guinea pigs anesthetized with pentobarbital. During and after 3 minutes of anoxia, endolymphatic pressure showed changes similar to those observed in systemic arterial pressure and cochlear blood flow. Fine fluctuations with influences of heartbeat and respiration were observed in the endolymphatic pressure. These facts indicate that the system is applicable for the accurate measurement of inner ear pressure, especially of endolymphatic pressure. In guinea pigs with middle ear filled with a saturated sodium chloride solution, both endo- and perilymphatic pressure measurements showed a gradual decline for 15 minutes and a slow recovery during the next 25 minutes. These pressure changes indicate that water is transferred through the semipermeable membrane of the inner ear due to modified osmolarity. The absence of a pressure gradient between the two fluids during the period of observation suggests that Riessner's membrane is not stiff.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call