| In order to understand mechanistically how neurons process information, it is necessary to know how postsynaptic potentials and currents are propagated and integrated. In the present work the propagation of current was analyzed by introducing a "current" cable equation to standard ("voltage") cable theory. Also, the concepts of characteristic impedance, Z;A general algorithm for deconvolution was developed for the empirical estimation of either the impulse-response function mentioned above or an unknown neuron's input function. The method works under conditions that: (1) minimize the duration of (and consequently the perturbation caused by) the identification experiments, and (2) allow the use of physiological (as opposed to artificial) probing signals.;An exact method (involving no approximations or truncation of series, for example) was developed for the empirical estimation of the non-reflecting monopolar neuron's parameters. The method involved the first three moments with respect to the origin of the (empirically determined) neuron impulse-response function ;The concept of reflection coefficient was introduced to the theory of electrotonus and a technique for detecting voltage signals' reflections was derived.;The processes of propagation and integration were assumed linear. Thus, the complete identification of the passive electrical behavior of a non-reflecting monopolar neuron stimulated at its soma was achieved by means of a quintuplet of mechanistic impulse-response functions. With the latter, both propagation and integration were performed as convolutions.;The impulse-response function ;Finally, it is suggested that experimental assessment of adaptiveness (plasticity) of the impulse-response functions of a neuron and its parts may be important in elucidating basic physiological mechanisms for self-organization underlying learning and memory in nervous systems. |
