Mechanical transduction by rat dorsal root ganglion neurons in vitro.
Although it is generally presumed that mechanical sensitivity of somatosensory nerve fibers results from the activation of mechanosensitive ion channels, a mechanically-gated whole-cell current has never been demonstrated in dorsal root ganglion (DRG) neurons. We performed patch clamp experiments on rat DRG neurons in culture, and report the first mechanically-activated current in somatosensory neurons (I(mech)). This whole-cell current is observed in most dorsal root ganglion neurons but not in non-sensory sympathetic ganglion neurons. The current-voltage relation of I(mech) indicates that it is a non-selective cation current. Sensitivity of I(mech) to block by gadolinium suggests that it may be mediated by a member of a family of mechanosensitive non-selective cation channels observed in many cell types. Sensitivity to benzamil supports this idea, and further suggests that the current might be mediated by a member of the degenerin/ epithelial sodium channel (DEG/ENaC) family.
McCarter
G C
GC
Department of Oral and Maxillofacial Surgery, University of California, San Francisco, CA 94143-0440, USA.
Reichling
D B
DB
Levine
J D
JD
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D005682:Gadolinium / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000187:drug effects / Q000502:physiology*; D007473:Ion Channels / Q000037:antagonists & inhibitors; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley
D007473:Ion Channels; C013407:benzamil; D000584:Amiloride; D005682:Gadolinium