Electrical properties of structural components of the crystalline lens.
The electrical properties of the crystalline lens of the frog eye are measured with stochastic currents applied with a microelectrode near the center of the preparation and potential recorded just under the surface. The stochastic signals are decomposed by Fourier analysis into sinusoidal components, and the impedance is determined from the ratio of mean cross power to input power. The data are fit by an electrical model that includes two paths for current flow: one through the cytoplasm, gap junctions, and outer membrane; the other through inner membranes and the extracellular space between lens fibers. The electrical properties of the structures of the lens which appear as circuit components in the model are determined by the fit to the data. The resistivity of the extracellular space within the lens is comparable to the resistivity of Ringer. The outer membrane has a normal resistance of 5 kohm . cm(2) but large capacitance of 10 muF/cm(2), probably because it represents the properties of several layers of fibers. The inner membranes have properties reminiscent of artificial lipid bilayers: they have high membrane resistance, 2.2 megohm . cm(2), and low specific capacitance, 0.8 muF/cm(2). There is so much membrane within the lens, however, that the sum of the current flow across all the inner membranes is comparable to that across the outer surface.
D000818:Animals; D001001:Anura; D004594:Electrophysiology; D005583:Fourier Analysis; D007908:Lens, Crystalline / Q000502:physiology*; D008433:Mathematics; D008564:Membrane Potentials; D008839:Microelectrodes
J Gen Physiol. 1960 Sep;44:169-94
13777653
J Physiol. 1976 Nov;262(2):285-300
1086902
Ann N Y Acad Sci. 1977 Dec 30;303:342-54
290301
Curr Top Eye Res. 1979;1:37-90
233657
Biophys J. 1979 Jan;25(1):151-80
262383
J Ultrastruct Res. 1977 Jan;58(1):10-21
833915
Biophys J. 1977 Jan;17(1):57-93
831857
Exp Eye Res. 1976 Dec;23(6):601-8
826402
Biochim Biophys Acta. 1976 Dec 14;457(3-4):353-84
793636
J Gen Physiol. 1974 Apr;63(4):460-91
4544879
J Gen Physiol. 1969 Mar;53(3):279-97
5767333
Invest Ophthalmol. 1974 Feb;13(2):147-50
4544153
Exp Eye Res. 1973 Apr;15(4):485-94
4540814
Exp Eye Res. 1969 Oct;8(4):406-12
5358236