Mechanosensitive K2P channels, TREKking through the autonomic nervous system

Abstract

TREK channels are background or leak potassium channels that are extensively expressed in the central, somatic peripheral and as recently demonstrated in the autonomic nervous system, where they are thought to play an important role in the modulation of neuronal excitability. Contrary to the expected behavior of “classic leak channels”, the channel activity can be strongly regulated by a number of physiological and non-physiological stimuli (physical, chemical or electrical). In fact, the TREK subfamily can be distinguished from other two-pore-domain potassium channels (K2P) by sensitivity to mechanical stimulation, suggesting an important role for this subfamily in the transduction of touch and pain. Our current understanding of the properties and functions of TREK channels is largely derived from the study of heterologously expressed channels, since the analysis of native K2P channels in real neurons is hampered by the difficulties in isolating specific channel subtypes in complex systems. The aim of this chapter is to summarize our current knowledge of TREK channels, paying particular attention to data obtained from natively expressed channels and from the autonomic nervous system.