Powerlab 4 26

Individual rats were placed in separate metabolic cages. These cages were attached to a urine collection funnel, which was placed over an electronic balance (A&D, Tokyo, Japan) to measure micturition behaviors. The amount of urine at each void was monitored using a multiport controller (PowerLab 4/26; AD Instruments, Dunedin, New Zealand). The first 48 h were considered an acclimatization period, then micturition behaviors in the last 24 h were used for analysis. Between 7:00 a.m. to 7:00 p.m. was defined as daytime and between 7:00 p.m. to 7:00 a.m. the next day as nighttime based on a previous study [34 (link)]. In this study, micturition parameters including 24 h urine volume, micturition frequency, daytime frequency, nighttime frequency, single voided volume, and total urine output were measured.

After laparotomy, a 24-G cannula needle was used to pierce the mesenteric branch vein, and the tip of the cannula reached the trunk of the superior mesenteric vein. The PVP was recorded with a PowerLab 4/26 multichannel physiological recorder (AD Instruments, Australia). The average value of 3-minute measurements was regarded as the PVP.

The data obtained by surface electromyography were transferred to a personal computer using PowerLab 4/26(AD Instruments Pty, Ltd.), and analyses were carried out in LabChart (AD Instruments Pty, Ltd.). The sampling rate was set at 1 kHz, and the bandpass filter was set to 10–500 Hz. In the analysis of the electromyography waveform, the mean amplitude was evaluated for a 5 s resting state (i.e., baseline) following full-wave rectification, and the standard deviation was calculated. The muscle activity of the tibialis anterior muscle during STS and VMI intervention was defined as the time from when the amplitude of the baseline full-wave rectified waveform exceeded two standard deviations (2SDs) until the amplitude decreased by 2SDs [40 (link)]. Then, the muscle contraction time and iEMG were determined, and the iEMG per second was calculated. The value was normalized by dividing it by the 100% maximum voluntary contraction (MVC) of the tibialis anterior muscle (%). The 100% MVC of the tibialis anterior muscle was measured before the STS evaluation by manually applying resistance to the participants with ankle plantar dorsiflexion of 0° in a chair sitting position for 5 s [41 (link)]. The value of the 100% MVC was calculated via the iEMG, and 1 s with a stable amplitude was used [41 (link)].

A balloon catheter (MILA Anal Sac Balloon Catheter 4fr × 17.5 cm) was advanced 3 cm through the cloaca to the urethra and connected to a second pressure transducer (ADInstruments MLT844 with a MEMSCAP 844-28 disposable dome coupler) to measure P_ura. Both pressure transducers were calibrated before insertion using a pressure gauge between 0 and 20 mmHg and recorded (1 kHz) simultaneously during stimulation using an acquisition system (ADInstruments PowerLab 4/26 and two ADInstruments bridge amplifiers) via the ADInstruments LabChart™ Software.

Electrocardiographic measurements were recorded for 1–5 min after light sedation of mice with isoflurane using needle electrodes. PowerLab 4/26 and Bio Amp modules (ADInstruments, Dunedin, New Zealand) were used for recordings in lead I configuration. ECG analysis was performed following automated algorithms with the labchart software (ADInstruments). The QT interval was calculated with the supplied ECG analysis tool, and invalid beats were excluded automatically. To monitor spontaneously occurring arrhythmias or cardiac events a mouse telemetry was conducted following a standard protocol. A transmitter ETA‐F10 (DSI, St. Paul, MN, USA) was implanted dorsal and after a postsurgical recovery phase of 7 days, measurements were conducted allowing free movements in special mouse telemetry cages. The cardiac potential changes were recorded for 24 h and sent to a receiver located on the bottom of the cages. The “holter”‐ ECGs were recorded and evaluated [19 (link)].