Format

Send to

Choose Destination
Neuron. 2013 Mar 6;77(5):899-914. doi: 10.1016/j.neuron.2012.12.035.

Kv1.1 channels act as mechanical brake in the senses of touch and pain.

Author information

1
Aix-Marseille-Université, CNRS, Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, UMR 7286, CS80011, Boulevard Pierre Dramard, 13344 Marseille Cedex 15, France.

Abstract

Molecular determinants of threshold sensitivity of mammalian mechanoreceptors are unknown. Here, we identify a mechanosensitive (MS) K(+) current (IKmech) that governs mechanical threshold and adaptation of distinct populations of mechanoreceptors. Toxin profiling and transgenic mouse studies indicate that IKmech is carried by Kv1.1-Kv1.2 heteromers. Mechanosensitivity is attributed to Kv1.1 subunits, through facilitation of voltage-dependent open probability. IKmech is expressed in high-threshold C-mechano-nociceptors (C-HTMRs) and Aβ-mechanoreceptors, but not in low-threshold C-mechanoreceptors. IKmech opposes depolarization induced by slow/ultraslow MS cation currents in C-HTMRs, thereby shifting mechanical threshold for firing to higher values. However, due to kinetics mismatch with rapidly-adapting MS cation currents, IKmech tunes firing adaptation but not mechanical threshold in Aβ-mechanoreceptors. Expression of Kv1.1 dominant negative or inhibition of Kv1.1/IKmech caused severe mechanical allodynia but not heat hyperalgesia. By balancing the activity of excitatory mechanotransducers, Kv1.1 acts as a mechanosensitive brake that regulates mechanical sensitivity of fibers associated with mechanical perception.

PMID:
23473320
DOI:
10.1016/j.neuron.2012.12.035
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center