FIG. 6: (Color online) P$_{k,}$$_{1}$/ (1 / 2 − χ$_{k}$ ) versus (1 / 2 − χ$_{k}$ ) for clusters of up to four cells. The second eigenvalue has the largest contribution to intensity of relaxation. is finite and it increases when the number of cells is increased. The increase of relaxation decrement when m → ∞ is physically limited by σ$_{S}$ ≪ δ (1 / 2 − χ$_{k}$ ) σ$_{1}$ , since the membrane conductivity is not strictly 0. Due to cluster’s shape and membrane properties, the variation of P$_{k,}$$_{1}$/ (1 / 2 − χ$_{k}$ ) and (1 / 2 − χ$_{k}$ ) with respect the eigenmode k determines a low frequency relaxation when the dipole-active eigenvalue χ$_{k}$ is close to 1/2. We note here that for dipole-active eigenmodes of ellipsoids the term (1 / 2 − χ$_{k}$ ) is called the depolarization factor and has analytical expression [37]. Prolate spheroids with longitudinal axis much larger than the transverse axis (needles) have the longitudinal depolarization factor approaching 0 and the transverse depolarization factor approaching 1/2. More precisely, for a long prolate spheroid, the longitudinal depo- larization factor scales as (1 / 2 − χ$_{2}$ ) ∝ a 2 $_{x}$/a 2 $_{z}$, a$_{z}$ > a$_{x}$ = a$_{y}$ , as a$_{x}$ → 0. On the other hand, extensive numerical calculations support the fact that cylinders with the same aspect ratio behave similarly to prolate spheroids [37]. Thus, it is not hard to observe that the low-frequency relaxation of linear clusters of cells connected by tight junctions is similar to that of a needle or a thin cylinder as long as the cluster and as thick as the junction. 22 GLYPH<s49> GLYPH<s48> GLYPH<s45> GLYPH<s52> GLYPH<s49> GLYPH<s48> GLYPH<s45> GLYPH<s51> GLYPH<s49> GLYPH<s48> GLYPH<s45> GLYPH<s50> GLYPH<s49> GLYPH<s48> GLYPH<s45> GLYPH<s49> GLYPH<s49> GLYPH<s48> GLYPH<s48> GLYPH<s48> GLYPH<s49> GLYPH<s48> GLYPH<s50> GLYPH<s48> GLYPH<s51> GLYPH<s48> GLYPH<s52> GLYPH<s48> GLYPH<s53> GLYPH<s48> GLYPH<s49> GLYPH<s32> GLYPH<s99>GLYPH<s101> GLYPH<s108> GLYPH<s108> GLYPH<s50> GLYPH<s32> GLYPH<s99>GLYPH<s101> GLYPH<s108> GLYPH<s108> GLYPH<s115> GLYPH<s51> GLYPH<s32> GLYPH<s99>GLYPH<s101> GLYPH<s108> GLYPH<s108> GLYPH<s115> GLYPH<s52> GLYPH<s32> GLYPH<s99>GLYPH<s101> GLYPH<s108> GLYPH<s108> GLYPH<s115> GLYPH<s80> GLYPH<s107>GLYPH<s44> GLYPH<s49> GLYPH<s47> GLYPH<s40> GLYPH<s49> GLYPH<s47> GLYPH<s50> GLYPH<s45> GLYPH<s41> GLYPH<s49> GLYPH<s47> GLYPH<s50> GLYPH<s45>