5-CT-activated inwardly rectifying K⁺ conductance in 5-HT neurons displays limited desensitization.

<p>(A) Time-course of a representative experiment (<i>n</i> = 6) showing the effect of increasing concentrations of bath applied 5-HT_1A receptor agonist, 5-CT on inwardly rectifying K⁺ conductance (G_{-110/-90 mV}) in a dorsal raphe 5-HT neuron. Extracellular solution contained 5.5 mM K⁺ and a mix of synaptic blockers (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140369#sec002" target="_blank">methods</a>). In this and the following Figs, time indicates duration of whole-cell configuration. (B) Current-voltage plot of the same experiment. Traces are averages of the last 13 individual ramps recorded before 5-CT application (Bsl); at the indicated 5-CT concentrations and following the washout of 5-CT (Wash; red trace). (C) Scatter plot of EC₅₀ values of 5-CT in individual neurons. Bars correspond to geometric mean ± 95% C.I. (D) Time-course of a representative experiment (<i>n</i> = 6) showing persistent activation of G_{-110/-90 mV} by 30 nM 5-CT. (E) Current-voltage plot of the same experiment. Traces are averages of 13 consecutive ramps recorded before 5-CT application (Bsl); during the maximal effect (Max) and at the end of the recording (End). (F) Scatter plot showing the percentage of maximal 5-CT effect (≈10 min in 5-CT) remaining 60 min after reaching the maximum (≈70 min in 5-CT) in individual recordings. Bars correspond to mean ± SD.