Open AccessFew cultured rat primary sensory neurons express a tolbutamide‐sensitive K + current
Author(s) -
Ristoiu Violeta,
Pluteanu Florentina,
Flonta MariaLuiza,
Reid G.
Publication year - 2002
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/j.1582-4934.2002.tb00194.x
Subject(s) - tolbutamide , nociceptor , dorsal root ganglion , chemistry , neuroscience , biophysics , sensory neuron , patch clamp , microbiology and biotechnology , sensory system , nociception , electrophysiology , biology , endocrinology , receptor , biochemistry , insulin
The response of dorsal root ganglion (DRG) neurons to metabolic inhibition is known to involve calcium‐activated K + channels; in most neuronal types ATP‐sensitive K + channels (K ATP ) also contribute, but this is not yet established in the DRG. We have investigated the presence of a K ATP current using whole‐cell recordings from rat DRG neurons, classifying the neurons functionally by their “current signature” (Petruska et al, J Neurophysiol 84: 2365–2379, 2000). We clearly identified a K ATP current in only 1 out of 62 neurons, probably a nociceptor. The current was activated by cyanide (2 mM NaCN) and was sensitive to 100 μM tolbutamide; the relation between reversal potential and external K + concentration indicated it was a K + current. In a further two neurons, cyanide activated a K + current that was only partially blocked by tolbutamide, which may also be an atypical K ATP current. We conclude that K ATP channels are expressed in normal DRG, but in very few neurons and only in nociceptors.