Molecular heterogeneity of large-conductance calcium-activated potassium channels in canine intracardiac ganglia

Elisabet Selga, Universitat de Girona
Alexandra Pérez-Serra, Universitat de Girona
Alba Moreno-Asso, Universitat de Girona
Seth Anderson, Masonic Medical Research Laboratory
Kristen Thomas, Masonic Medical Research Laboratory
Mayurika Desai, Masonic Medical Research Laboratory
Ramon Brugada, Universitat de Girona
Guillermo J. Pérez, Universitat de Girona
Fabiana S. Scornik, Universitat de Girona


Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue. © 2013 Landes Bioscience.