Development of the L-type CaV / BK Complex Simulator (I): electrophysiological interaction

Abstract

Complexes formed by voltage-activated calcium channels (CaV) and high-conductance potassium channels activated by Ca2+ (BK) have been studied in smooth muscle, secretory cells and in synaptic terminals, where they regulate muscle contraction, secretory activity, and neurotransmission. However, the complex formed by L- type CaV channels and BK in the soma has been poorly treated. Based on immunostaining studies showing the coexistence of these channels in the neuron soma, their possible interaction was theoretically studied. Two simulators based on the Hodgkin and Huxley formalism were developed to perform virtual experiments on current and voltage clamp. The mathematical models were implemented in Visual Basic® 6.0 and were solved numerically. The results indicate that the BK channels were activated with internal Ca2+ at mM concentrations. The BK channels follow the kinetics of L-type CaVs. The interaction of L-type CaV – BK complex in the soma produced a decrease in neuronal excitability.