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Most of the time, calcium is not the most important ion in terms of active propagation of an action potential along an axon. It is usually sodium and potassium which play the key roles here. In most living things the concentrations of ions for the intracellular and extracellular solutions are similar. For an action potential, you usually have an influx of ...


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As WYSIWYG wrote, energy is the answer, but to clarify the dependence of energy from momentum... sorry, the dependence of frequency from wavelength, have a look at the animation on this web page: http://www.acs.psu.edu/drussell/Demos/wave-x-t/wave-x-t.html, posted here in what I believe complies with fair use legislation: It represents a sinusoidal wave, ...


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It is possible to tag molecular motors with fluorescent proteins. It may impede with its movement but as this paper describes, a variant can be created that doesn't have cargo binding ability. Constitutively active kinesin motors can be generated by truncations that remove autoinhibitory and cargo-binding regions of the polypeptide. For this work, ...


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Very nice question! I'll go through your three questions sequentially. Q1: Why does lower capacitance increase "the effectiveness of nearby nodes" or allow the depolarizing voltage to "travel not by ion diffusion, but as an electric field"? A: Capacitance basically results in sequestering of charge of opposite polarities along the cell membrane, which ...


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Excellent question! The difference is the fact that the rheobase is an example of a threshold measure. The threshold, as you correctly suggest, is the minimal energy (typically current level and not voltage as you suggest) to excite neural tissue. The threshold applies only under the specific experimental parameter settings used. These parameters include the ...


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The Hodgkin-Huxley model: $$I=C_m\frac{dV}{dt} + g_k(V_m - V_k) + g_{Na}(V_m - V_{Na}) + g_l(V_m- V_l)$$ Where $C_m$ is membrane capacitance per unit area and $g_i$ are membrane conductances. Reducing the number of channels does not affect capacitance per se (it does in a way) but what it basically does is to reduce membrane conductance to leak channels ...



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