# Search Results

###### Studies in Rheoencephalography (REG)

processes before its reserves have been compromised when the delivery of substrate reaches 'critical' values. However, the flip side of this argument is that, paradoxically, the brain cannot tolerate significant increases in the volume of the contents of the rigid container in which it is enclosed. Moreover, because the brain’s own store of energy-generating substances (glycogen/glucose, oxygen) is small (so small that, at normal rates of adenosine phosphate production, the stores of glycogen in the brain would be exhausted in less than 3 min) it is uniquely dependent

###### A short tutorial contribution to impedance and AC-electrokinetic characterization and manipulation of cells and media: Are electric methods more versatile than acoustic and laser methods?

radii provide the solution for the geometric problem, the electric problem for a single shell ellipsoid can be solved, assuming a series circuit of three resistor-capacitor (RC) pairs for the internal, membrane and external media along each semiaxis. The length of the three external elements (e.g. Z e a * $Z_{e}^{a*}$ along semiaxis a ) must be such that it ensures the maximal possible potentials at the poles. There are at least two arguments for the correctness of a description by three stacked "finite" elements (RC pairs) along each semiaxis: For

###### A single differential equation description of membrane properties underlying the action potential and the axon electric field

in the membrane of an axon in terms of conductance. By and of itself, the hyperbolic conductance term (1b) is intrinsic to the displacement of the membrane potential, V m from its resting value, such that: (1c) 1 G i n cosh n π X ∝ V m $$\frac{1}{{{G}_{in}}\cosh n\pi \text{X}}\propto {{V}_{m}}$$ The inverse variation (1c) is consistent with the fact that voltage varies inversely with conductance [ 25 ]. For initial computational generality, nπ multiples of Χ are included in the cosh argument. The left-hand units of (1c) is Ω. B Axon