Ph.D. Tezi Görüntüleme

      In this dissertation, kinetics of ionic currents in cerebellar Purkinje cell is detaily investigated for disjointed soma, main dendrite, thick dendrite and spiny dendrite compartmental models. Current-clamp analysis is conducted for each of these compartments. A Purkinje cell model is constructed by combining these compartments, then effects of ionic currents on somatic membrane potential are examined for several cases.

       Compartmental modeling approach considers high degree details of physiology and morphology of the neuron. The model includes ten different voltage- and ionic concentration-dependent active membrane channels defined in literature to be present in Purkinje cells. The parameters of the mathematical equations determining activation and inactivation kinetics of the channels are assigned in such a way that the potentials obtained from this model are similar to the potentials recorded in real experiments.

       Steady-state activation and inactivation curves of ionic currents are calculated from their respective rate functions in detailed modeling studies reported in literature on Purkinje cell. In this study, curves for data of steady-state activation and inactivation of ionic currents are fitted using Marquardt-Levenberg parameter estimation algorithm. Also curves for data of activation and inactivation time constants, and probability distributions of ionic channel gates are fitted. Therefore kinetics of ionic currents can be interpreted concretely, also simulation time is decreased considerably in models include a lot of compartments.

      Keywords: Purkinje cell, Compartmental modeling, Ionic current, Kinetics, Active membrane, Activation, Inactivation