First Author | Hao J | Year | 2013 |
Journal | Neuron | Volume | 77 |
Issue | 5 | Pages | 899-914 |
PubMed ID | 23473320 | Mgi Jnum | J:197938 |
Mgi Id | MGI:5494919 | Doi | 10.1016/j.neuron.2012.12.035 |
Citation | Hao J, et al. (2013) Kv1.1 channels act as mechanical brake in the senses of touch and pain. Neuron 77(5):899-914 |
abstractText | 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 Abeta-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 Abeta-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. |