EN
The prefrontal cortex is involved in cognitive function. It has been suggested that dysfunction of mPFC occurs in widespread neuropsychiatric disorders. The purpose of this study was to classify K+ channel currents along their kinetic properties in mPFC pyramidal neurons. Channel current recordings were performed from dispersed pyramidal neurons in cell-attached configuration in symmetrical K+ solutions. The kinetic properties of 100 channel currents were analysed. A total of 27% resembled leak, TREKlike channel currents. Their mean amplitude was 6.9 pA, dwell time was 1.31 ms, and NPo was 0.009 at -50 mV. Their outward and inward conductances were 160 and 150 pS, respectively. The channel currents were strongly mechanosensitive. A total of 27% resembled TASK-like channel currents. Their mean amplitude was 2.0 pA, dwell time was 0.58 ms and NPo 0.11 at -50 mV. Inward and outward conductances were 48 and 71 pS, respectively. A total of 34% were BK-like channel currents. Their amplitude was 5.8 pA, dwell time was 1.1 ms, and NPo was 0.03 at +25 mV. Their outward conductance was 177 pS. In cell-attached configuration, the BK channel currents were only outward. The application of Ca2+ ions from the intracellular side in inside-out configuration strongly activated these channels. A total of 5% channel currents were not classified. Surprisingly, we did not find voltage dependent K+ channel currents. We concluded that the leak-type channel currents could be important players in setting the level of membrane potential in mPFC pyramidal neurons.