Longitudinal fluid movements in the cochlea under normal and abnormal conditions

Abstract

Solutes in the cochlear fluids are in a highly dynamic state. The rates of turnover of some ions in endolymph have been quantified using radiotracers (Konishi et al, 1978; Sterkers et al, 1982). These studies established entry half times for K⁺, for example, of 55 to 60 mins. However, the basic physiologic mechanisms underlying cochlear fluids turnover have been difficult to establish. The most fundamental question in this regard, is whether the fluids are secreted in volume and whether longitudinal fluid flow represents a significant fluid turnover component. In the studies summarized here, longitudinal cochlear fluid movements have been quantified in endolymphatic and perilymphatic scalae under a variety of experimental conditions.