Figure 5.

Quantification of the variability of single-channel membrane current (Im) dynamics to evaluate the membrane-coated electrode performance under the voltage-clamp mode of cell-attached recordings. (A) Graphical diagrams of the recording configuration. (B) Representative current trace of Im obtained by using standard patch electrode (C) Representative current trace of Im obtained by using membrane-coated electrode (D) All-points histogram of Im obtained by using standard patch electrode (E) All-points histogram of Im obtained by using membrane-coated electrode (F) Comparison of the signal-to-noise ratio (SNR) in Im with (+) or without (−) membrane coating. The SNR was assessed in decibels relative to the carrier wave (dBc). This measurement was derived from a real-valued sinusoidal Im determined by a modified periodogram using a Kaiser window with a β value of 38, corresponding to the length of the input signal. (G) Comparison between the start and end points of (SNR) in Im with (+) or without (−) membrane coating. During the entire recording period of 1 minute, we took the first 10 seconds as the start point and the last 10 seconds as the endpoint. All data are obtained from the voltage-clamp mode of cell-attached recordings from DN1p circadian clock neurons in Drosophila, by using standard patch electrodes with (+) membrane-coated electrodes (N=3) and without (−) membrane coating (N=3). Single-channel membrane current was evoked by a single-step pulse change from −70 mV holding potential to +60 mV holding potential. One DN1 neuron was recorded per fly. Single-electrode recordings were performed in random order between no coating and coating. The statistics are unpaired t-test with **p < 0.01 (F) and two-way ANOVA with Šídák’s multiple comparisons test with ***p < 0.001 and ns indicates non-significance (G).