Mitochondria optical parameters are dependent on their energy state: a new electrooptical effect?

Abstract

The membrane potential of mitochondria determines, to a large extent, their functional state and the response to the changing conditions of the environment. A correlation was found between the changes in the optical characteristics of isolated mitochondria and the composition of the incubation medium, which determines the potential of the inner mitochondrial membrane. The measurements performed by the method of coherent phase microscopy made it possible to establish a linear dependence of the phase height on the value of the membrane potential and to calculate the electrooptical constant, K approximately equal to (3-4) x 10(-7) m/V.

Extension of the concept of an anomalous water component to images of T-cell organelles

“…Therefore, it is logical to assume that the component referred to as 4-water 2 somehow affects microscopic phase images of cells and is detectable in these objects. [7][8][9][10][11] However, we have not found any mention of such a phenomenon in the literature. This also applies to cell images obtained by various interference microscopy methods; no effect of 4-water on the images has been reported.…”

“…Details of the technique and specimen preparation have been described earlier. [8][9][10][11] The functional state of TCs was changed by the addition of compounds with a known mechanism of pharmacological action. We used the concentrations of compounds generally reported in the literature for treatment of whole cells and organelles.…”

“…[8][9][10][11] All experiments were performed with the Olympus MD Plan 20* objective, NA 0.4. The raster method of image recording was used in contrast to the studies that employed the multistep method.…”

“…Common for all interference methods is the representation of the images in the form of a two-dimensional distribution hðx; yÞ of optical path difference (OPD) in the image plane. The most important and the unique advantage of the interference microscopy is the measurement of OPD in absolute units of wavelength [7][8][9][10][11][12][13][14][15][16][17][18][19] with a very high precision, which is hardly achievable or is even impossible with other methods. Normally, the phase image is described as the function hðx; yÞ ¼ Z ðnðx; y; zÞ − n 0 Þdz in the image plane ðx; yÞ, where nðx; y; zÞ and n 0 are the refractive indices of the object and the environment, respectively.…”

“…[12][13][14][15] Quantitative analysis of phase images of various cell types [7][8][9][10][11][12] has shown that the changes in their optical parameters caused by external factors cannot be solely explained by alterations of their proteins. In solving this problem, we suggested [7][8][9][10][11][12] that not only the change in protein RI averaged by the cell volume should be taken into account, but the possibility that the RI of intracellular water is changed should also be assumed. To test this hypothesis, we took advantage of the unique properties of cell phase images 16 and original algorithms.…”