Sealing of the round window reversibly affects auditory brainstem response latencies.
The round window (RW) niche was sealed in 12 adult female albino Sprague-Dawley rats. Electrophysiological auditory function was measured with a computerized auditory brainstem response (ABR) recording technique, using 1- and 6 kHz stimuli. ABR measurements were performed prior to closure of the niche, immediately after the sealing, and 4 h, 24 h and 7 days later. After sealing, the latencies elicited by a 6 kHz stimulus increased, but returned to normal between 24 h and 7 days after closure. Stimulation with 1 kHz did not influence the latencies in such a clear-cut manner as when using 6 kHz. It is conceivable that sealing of the RW deprives a minor fraction of oxygen supplied to the basal part of the cochlea through the RW membrane, a procedure which by us is monitored as transient electrophysiological changes.
Spandow
O
O
Department of Oto-Rhino-Laryngology and Head and Neck Surgery, University Hospital, Umeå, Sweden.
Anniko
M
M
Möller
A R
AR
D000818:Animals; D001933:Brain Stem / Q000502:physiology; D015687:Cell Hypoxia / Q000502:physiology; D003051:Cochlea / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D051381:Rats; D011919:Rats, Inbred Strains; D012405:Round Window, Ear / Q000502:physiology*; D013997:Time Factors