Quantitative phase image of cells.

<p>Quantitative phase image of the cells corresponding to the control experiment (), ensuring no missed staining during a typical measurement duration. The figure corresponds to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030912#pone.0030912.s001" target="_blank">Video S1</a> containing the evolution in time of neuronal body shapes during control and excitotoxic stimulation.</p

Images corresponding to experiment of <b>Fig. 3</b>.

<p>Cells corresponding to the experiment depicted in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030912#pone-0030912-g003" target="_blank">Fig. 3</a> when the glutamate pulse occurred at . Phase images at <b>A </b> (before stimulation), and <b>B</b> at (after stimulation); note that cells 1–3 present morphological changes such as round cell shape or nucleus condensation, while cell 4 appears normal. Color images at <b>C </b> and <b>D </b>: note cells 1–3 clearly stained by trypan blue, unlike cell 4. Some viable and dead cells are shown by respectively arrows and arrowheads in all subfigures.</p

Phase responses resulting from different glutamate applications.

<p><b>A</b> reversible responses ( glutamate pulse), and <b>B</b> irreversible responses ( glutamate pulse). Both types of phase curves are representative of measurements on cells each.</p

Optical setup employed for digital holography measurements.

<p>Sketch of the optical arrangement. : half-wavelength plate, (P)BS: (Polarizing) beam splitter, M: Mirror, FM: Flip mirror, BE: Beam expander, C: Condenser lens, MO: Microscope objective, FL: Field lens, RO: Relay optics, IM: Image plane, S: specimen, O, R: Propagation vectors of respectively object and reference waves, : Off-axis angle.</p

Cellular phase signal.

<p>Monitoring over time of the phase signal on several cells under a () glutamate pulse.</p

RBC Equilibrium Shape.

<p>Straigth line: Equilibrium shape that arises from bending energy minimization (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040667#pone.0040667.s001" target="_blank">Text S1</a>) and which was used in the calculations to derive eigenmodes of the bending deformation energies depicted in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040667#pone-0040667-g003" target="_blank">Figure 3B,C</a>. Dashed line: Shape of deformed cell.</p

PCA Results.

<p>Normalized PCA modes (A) of a single cell (B) of a paraformaldehyde fixed cell (C) of a group of n = 198 cells. The spatial distribution of the normalized mode amplitude is color coded. (D) Phase image of erythrocyte with typical ROI for PCA analysis (E) Eigenvalues of PCA modes of A,B,C (Log Scale). Standard deviations of the values are indicated by error bars.</p

ATP Depletion in RBC.

<p>(A) Fluctuation amplitudes of the first six PCA modes in a population of n = 198 (no ATP depletion), 43 (1 h ATP depletion), 47 (2 h ATP depletion), 36 (4 h ATP depletion) cells. (B) Assessment of intracellular ATP level at different instants of incubation time in depletion medium through the measurement of chemiluminescence intensity of luciferin luciferase assay in RBC cell solution.</p

Experimental and Theoretical Comparison.

<p>(A) Degeneracy free representation of PCA modes. The separable modes 7 (degeneracy of 2) and 9 in this representation are obtained from an appropriate linear combination of the degenerate modes 12,13 and 14 of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040667#pone-0040667-g001" target="_blank">Figure 1C</a>. Both representations are equivalent, because they span the same subspace. (B) Eigenmodes that minimize Laplace deformation energy shown in the ROI. Eigenmodes are plotted as functions (C) Eigenmodes that minimize BCH Deformation Energy shown only in the ROI (D) Comparison of theoretical and measured fluctuation amplitudes.</p

Determination of E_cl with a [Cl⁻]_intrapip of 139 mM.

<p>Values are means ± SEM. For all conditions, equations, R² and E_cl were obtained by using a quadratic polynomial fit (ORIGIN).</p