Source data for the study "High-pass noise suppression in the mosquito auditory system" in <i>Culex pipiens </i>mosquito.

The Matlab script and the bandpass-filtered source data from the electrophysiological acoustic experiments with male and female <i>Culex pipiens</i> mosquitoes.Each data file contains a series of tones with stepwise increase of frequency. First channel - electrophysiological recording from the auditory neuron(s) by the electrode in the antennal nerve of mosquito. Second channel - signal from the microphone located near mosquito. Stimulation is done via phase-calibrated speakers.<b>hilb.m</b> A script in Matlab, performing the analysis of the instantaneous phase shift between the two recording channels. It takes a fragment of recording cut from the source file, containing a single stimulation tone. <b>d</b><b>ata_example/cp126_180.wav</b> Example of such fragment. <b>data_example/</b><b>cp126_180.wav.txt</b> Output of the script <b>Method of recording and data processing</b>Individual mosquitoes were fixed by attachment to a 10×5 mm copper-covered triangular plate by a flour paste with addition of sodium chloride, as described in Lapshin, Vorontsov, 2013. Focal extracellular recordings from the axons of the antennal nerve were made with glass microelectrodes (1B100F–4, WPI Inc., Sarasota, FL, USA) filled with 0.15 M sodium chloride and inserted at the scape–pedicel joint. After the penetration of the cuticle, the electrodes had a resistance of 10–60 MΩ.Neuronal responses were amplified using a home-made AC amplifier (bandpass 5–5000 Hz). For stimulation, two orthogonally oriented stationary speakers were used; they created a vector superposition of acoustic waves at the point of mosquito antenna, as described in detail in Lapshin, Vorontsov (2019). The mosquito was positioned at the crossing of the axes of two speakers in such a way that the antenna's flagellum was perpendicular to the directions of sound waves originating from each of the two speakers. This approach enabled us to set the desired direction of the acoustic vector relative to the antenna flagellum.A differential microphone (NR-231-58-000, Knowles Electronics, Itasca, IL, USA) positioned next to the mosquito on a micropositioner with axial rotation feature recorded the stimulation signals. Neuronal responses and stimulation signals were digitized using an Е14-440 A/D board (L-Card, Moscow, Russian Federation) at 20 kHz sampling rate, and LGraph2 software.Calibration of the stimulating equipment was performed using the same differential microphone. The differential microphone together with its amplifier was previously calibrated in the far field using a B&amp;K 2253 sound level meter with a B&amp;K 4176 microphone (Brüel &amp; Kjær, Nærum, Denmark). All sound level data in this study are given on a logarithmic scale in dB RMS SPVL (root mean square sound particle velocity level), with a reference level of 0 dB being equal to 4.85 × 10⁻⁵ mm/s.At the beginning of the experiment, as the electrode was gradually advanced into the antennal nerve, the preparation was continuously stimulated with tonal pulses (filling frequency 200 Hz for male mosquitoes, 100 Hz for female mosquitoes, amplitude 60 dB SVPL, duration 80 ms, period 600 ms). In this searching procedure, groups of JO neurons situated orthogonal to the antenna oscillation could be overlooked. To avoid this, the vector of the acoustic wave was periodically changed by 90°.A response amplitude of 500 µV (peak-to-peak) or more was considered sufficient for subsequent measurements. More detailed methodology for measuring the auditory receptor thresholds was described earlier (Lapshin, 2012a, 2012b; Lapshin, Vorontsov, 2013).The phasic properties of the auditory response were measured by stimulating the preparation with tonal pulses that incrementally varied from low to high frequencies (50 dB SPVL and 10 Hz increments for male mosquitoes, 60 dB SPVL and 5 Hz increments for female mosquitoes). The duration of individual pulses was typically 3–4 seconds; however, it could be increased in the presence of occasional spontaneous interference in the neuronal response. The interval between successive pulses was maintained at a constant 0.15 seconds.Both the stimulation control circuit (microphone and the microphone amplifier) and the electrophysiological amplification circuit were pre-calibrated for phase shifts, and the data recorded from the neurons were adjusted accordingly.Before the measurement of the phase shift, signals in both recording channels (acoustic stimulation and neuronal response) were bandpass-filtered using the Sound Forge 10 PRO software (Sony, Japan). The purpose of this procedure was to isolate the fundamental frequency in each channel while simultaneously suppressing harmonics and noise. The filter was adjusted to the stimulation frequency in each case. To control for artifacts of digital frequency filtering, a pre-synthesized sinusoidal signals of 50 and 100 Hz with predetermined phase shifts between the channels (typically –90°, 90°, and 180°) were filtered in the same way. After the filtering procedure, the phase shift between the signals in the two channels remained unchanged.To measure the phase difference between the stimulus and response signals, an instantaneous phase functions for both signals were calculated in Matlab via the Hilbert transform, as was proposed for the analysis of mosquito flight sounds by Aldersley et al. (2014). The phase shift was measured in the second half of a tonal pulse when the system entered a steady-state regime. For each tonal pulse, the median value of the phase shift was taken to plot the phase-frequency characteristic.本数据集包含针对雌雄尖音库蚊（Culex pipiens）开展电生理声学实验所得到的带通滤波原始源数据与Matlab脚本。每个数据文件包含一系列频率逐步递增的纯音信号。第一通道为通过插入蚊子触角神经的电极采集的听神经元电生理信号；第二通道为放置于蚊子附近的麦克风采集的信号。刺激通过相位校准扬声器完成。 <b>hilb.m</b> 为一款Matlab脚本，用于分析两路记录通道间的瞬时相移。该脚本会截取源文件中包含单一声刺激纯音的片段进行分析。<b>data_example/cp126_180.wav</b> 为上述片段的示例文件。<b>data_example/cp126_180.wav.txt</b> 为该脚本的输出结果。<b>记录与数据处理方法</b> 单个蚊子通过添加了氯化钠的面粉糊固定于10×5 mm覆铜三角板上，具体操作参见Lapshin与Vorontsov 2013年的研究。采用填充0.15 M氯化钠溶液的玻璃微电极（1B100F–4，美国WPI公司，萨拉索塔，佛罗里达州），于柄节-梗节关节处插入，实现触角神经轴突的细胞外记录。电极穿透表皮后，电阻为10–60 MΩ。 神经反应通过自制交流放大器（通带5–5000 Hz）进行放大。刺激采用两台正交放置的固定扬声器，可在蚊子触角位置产生声波的矢量叠加，具体细节参见Lapshin与Vorontsov 2019年的研究。蚊子被放置于两台扬声器轴线的交点处，使其触角鞭毛与两台扬声器发出的声波传播方向均垂直，由此可灵活设置声矢量相对于触角鞭毛的期望方向。 采用带轴向旋转功能的微定位器将差分麦克风（NR-231-58-000，美国Knowles Electronics公司，伊塔斯卡，伊利诺伊州）放置于蚊子附近，采集刺激信号。神经反应与刺激信号通过Е14-440 A/D采集卡（俄罗斯L-Card公司，莫斯科）以20 kHz采样率进行数字化，配套软件为LGraph2。 刺激设备的校准采用同一台差分麦克风完成。该差分麦克风及其放大器此前已通过B&K 2253声级计搭配B&K 4176麦克风（Brüel & Kjær公司，奈鲁姆，丹麦）在远场环境下完成校准。本研究中所有声级数据均以对数尺度表示为dB RMS SPVL（均方根声质点速度级），参考电平0 dB对应4.85×10⁻⁵ mm/s。 实验初始阶段，随着电极逐步向触角神经推进，持续以纯音脉冲刺激标本：雄蚊的刺激脉冲频率为200 Hz，雌蚊为100 Hz，幅度60 dB SVPL，时长80 ms，周期600 ms。在此搜寻过程中，可能会遗漏与触角振动正交的琼氏器（JO）神经元群。为避免该情况，需定期将声波矢量旋转90°。 当神经反应峰峰值幅度达到500 µV及以上时，可认为该标本满足后续测量要求。听觉感受器阈值的更详细测量方法已在此前研究中发表（Lapshin, 2012a, 2012b; Lapshin, Vorontsov, 2013）。 听觉反应的相位特性通过逐步递增频率的纯音脉冲刺激标本进行测量：雄蚊的刺激强度为50 dB SPVL，频率步进10 Hz；雌蚊为60 dB SPVL，频率步进5 Hz。单个脉冲的时长通常为3–4秒，若神经元反应出现偶发自发干扰，则可适当延长时长。连续脉冲间的间隔固定为0.15秒。 刺激控制回路（麦克风与麦克风放大器）与电生理放大回路均预先进行相移校准，并据此对神经元记录数据进行校正。 在测量相移前，已通过Sound Forge 10 PRO软件（索尼公司，日本）对两路记录通道（声刺激信号与神经反应信号）进行带通滤波。该操作的目的是分离每个通道中的基频成分，同时抑制谐波与噪声。滤波器参数需针对每次实验的刺激频率进行调整。为验证数字滤波的伪影影响，预先合成了通道间具有预设相移（通常为–90°、90°与180°）的50 Hz和100 Hz正弦信号，并以相同方式进行滤波。滤波后，两路信号间的相移保持不变。 为测量刺激信号与反应信号间的相位差，采用Matlab通过希尔伯特变换（Hilbert transform）计算两路信号的瞬时相位函数，该方法由Aldersley等人2014年提出，用于分析蚊子飞行声音。相移的测量选取纯音脉冲的后半段，此时系统进入稳态。针对每个纯音脉冲，取相移的中值用于绘制相频特性曲线。