[A hyperpolarization-activated current in rat menthol-sensitive sensory neurons].

In the present study we have investigated the correlation between hyperpolarization-activated current (1(h)) and menthol-activated current (I(TRPM8)) in rat dorsal root ganglion (DRG) neurons. We showed that I(h) is present in 89% of menthol-sensitive neurons which makes its presence reliable, though not absolute, criterion for pre-selection of such neurons. Endogenous I(h) recorded from different neurons exhibited variable density and activation kinetics. Based on the analysis of I(h) activation kinetics we hypothesize that the population of hyperpolarization-activated channels in menthol-sensitive DRG neurons is mainly represented by HCN1, HCN2 and HCN3 channels. The expression of HCN4 isoform in these cells is very low.