title: Compartmentalization of the outer hair cell demonstrated by slow diffusion in the extracisternal space.
abstract: In the outer hair cell (OHC), the extracisternal space (ECiS) is a conduit and reservoir of the molecular and ionic substrates of the lateral wall, including those necessary for electromotility. To determine the mechanisms through which molecules are transported in the ECiS of the OHC, we selectively imaged the time-dependent spatial distribution of fluorescent molecules in a <100 nm layer near the cell/glass interface of the recording chamber after their photolytic activation in a diffraction-limited volume. The effective diffusion coefficient was calculated using the analytical solution of the diffusion equation. It was found that diffusion in the ECiS is isotropic and not affected by depolarizing the OHC. Compared with free solution, the diffusion of 10 kDa dextran was slowed down in both the ECiS and the axial core by a factor of 4.6 and 1.6, respectively.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Gliko
authors.forename: Peter
authors.initials: P
authors.lastname: Saggau
authors.forename: William E
authors.initials: WE
authors.lastname: Brownell
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D018072:Hair Cells, Auditory, Outer / Q000737:chemistry*; D008956:Models, Chemical
chemical_list: D001704:Biopolymers
references.citation: Trends Neurosci. 1989 Feb;12(2):54-9
references.pmid: 2469211
references.citation: Hear Res. 1996 Jul;96(1-2):33-40
references.pmid: 8817304
references.citation: Curr Opin Neurobiol. 1996 Jun;6(3):379-86
references.pmid: 8794086
references.citation: Am J Physiol. 1994 Feb;266(2 Pt 1):C467-79
references.pmid: 8141262
references.citation: J Math Biol. 2000 Apr;40(4):372-82
references.pmid: 10853798
references.citation: J Neurosci. 2000 Dec 15;20(24):8996-9003
references.pmid: 11124975
references.citation: Eur Arch Otorhinolaryngol. 1990;247(1):12-5
references.pmid: 2310542
references.citation: Neuroreport. 1997 Jul 28;8(11):2517-21
references.pmid: 9261819
references.citation: Nature. 2002 Sep 19;419(6904):300-4
references.pmid: 12239568
references.citation: J Neurosci. 1992 Jan;12(1):77-85
references.pmid: 1370324
references.citation: Biophys J. 2002 Sep;83(3):1650-60
references.pmid: 12202388
references.citation: Biophys J. 1998 Jun;74(6):3302-12
references.pmid: 9635784
references.citation: Biophys J. 1996 Aug;71(2):1140-51
references.pmid: 8842251
references.citation: Science. 1985 Jan 11;227(4683):194-6
references.pmid: 3966153
references.citation: Curr Opin Biotechnol. 1997 Feb;8(1):58-64
references.pmid: 9013655
references.citation: Trends Cell Biol. 2001 Jul;11(7):298-303
references.pmid: 11413041
references.citation: Am J Physiol Cell Physiol. 2002 May;282(5):C1076-86
references.pmid: 11940523
references.citation: Proc Natl Acad Sci U S A. 1989 Jul;86(14):5385-9
references.pmid: 2748592
references.citation: Ear Hear. 1990 Apr;11(2):82-92
references.pmid: 2187727