Transverse and lateral mobility in outer hair cell lateral wall membranes

John S. Oghalai, Tung D. Tran, Robert M. Raphael, Takashi Nakagawa, William E. Brownell

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Cochlear outer hair cell (OHC) electromotility is associated with the cell's lateral wall. The lateral wall contains two distinct membranes: the plasma membrane (PM) and the subsurface cisternae (SSC). We explored biophysical characteristics of these lipid structures using membrane-specific fluorescent dyes. We have previously demonstrated that di-8-ANEPPS stains the PM while NBD-C6-ceramide partitions to the SSC. In this report we show that NBD-cholesterol also partitions to the SSC. Transmigration of the SSC dyes across the PM was visualized under confocal microscopy, after separating the two membranes using the micropipette aspiration technique. The transverse mobility of NBD-cholesterol was faster than that of NBD-C6-ceramide. We then measured the lateral mobility of the dyes within both the PM and the SSC using fluorescence recovery after photobleaching (FRAP). The diffusion coefficients at 12-37°C and the activation energies for diffusion were found to be similar to those of other biological membranes. These data indicate that both the PM and the SSC are membranes in the fluid phase, with no evidence of temperature-dependent phase transitions. Our observations are consistent with a fluid-mosaic model of the lateral wall membranes. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)19-28
Number of pages10
JournalHearing Research
Volume135
Issue number1-2
DOIs
Publication statusPublished - Sep 1999

All Science Journal Classification (ASJC) codes

  • Sensory Systems

Fingerprint

Dive into the research topics of 'Transverse and lateral mobility in outer hair cell lateral wall membranes'. Together they form a unique fingerprint.

Cite this