Powerlab 26t

Core temperature (T_c) was measured using a rectal probe (Ret‐1 Special, Physitemp, Clifton, NJ, USA) which was self‐inserted 15 cm past the sphincter muscle. Skin temperature (T_sk) in the quadriceps, hamstrings and calf for both legs was measured using commercially available thermistors (IT‐18, Physitemp) which were securely held in place using medical tape. T_c and T_sk were recorded online using a commercially available thermocouple metre (TC‐2000, Sable Systems International, Las Vegas, NV, USA) connected to a data acquisition system (PowerLab 26T, ADInstruments, Dunedin, New Zealand). Foot T_sk was collected via wireless temperature loggers (DS1922L iButton Thermochron, Measurement Systems Ltd, Newbury, UK). Following the protocol, foot temperature was exported from the wireless temperature loggers in 30‐s bins using a specialist logging software (iButtons, Measurement Systems Ltd). Data were then imported and analysed in Microsoft Excel software, reported as 2‐min averages. In addition, mean skin leg temperature (T¯Leg) was calculated as an unweighted average of quadriceps, hamstrings, calf and foot T_sk. Similarly, mean skin upper‐leg temperature (T¯Upper−Leg) was calculated as the unweighted average of quadriceps and hamstrings T_sk, and mean skin lower‐leg temperature (T¯Lower−Leg) was calculated as the unweighted average of calf and foot T_sk.

At day 14 or 28 postoperation, we assessed erectile function by measuring max ICP and MAP. After anesthesia, the bilateral cavernous nerves were exposed. The right penile crus was then exposed, and a 23-gauge needle containing heparin solution was inserted for ICP measurement. One 24-gauge indwelling needle connected to a PE-50 tube containing heparin was inserted into the left carotid artery to monitor systemic MAP. The stimulus parameters of the cavernous nerve were 5 V, 15 Hz, 5-millisecond pulse width, and 60-second duration. The changes in MAP and ICP were recorded by a pressure transducer system (PowerLab26T; AD Instruments). The data were analyzed by LabChart8 software (AD Instruments). The penises were harvested for further examination.

The experiment was designed using PsychToolbox (Brainard, 1997 (link), Kleiner et al., 2007 ) implemented in MATLAB2019a (The MathWorks Inc., Natick, MA, USA) on Windows. Visual stimuli were presented on a 19″-monitor. Grip force signals were acquired with a strain-gauge based isometric dynamometer with a 0–800 Newton (N) range (MLT004/ST, AdInstruments Ltd, New Zealand). Grip force signals were sampled at 1000 Hz using PowerLab 26T data acquisition system and LabChart software (AdInstruments Ltd, New Zealand). Acquired signals were continuously transferred to a custom-written MATLAB interface that used the grip force signals to update the visual display in real-time.

Control ECG (lead II) was recorded using PowerLab 26T (AD Instruments, Colorado Springs, CO, USA) for 5 min under general anaesthesia with 3.0% sevoflurane. Thereafter, the right cervical vagus nerve (CVN) was gently detached and ligated with an 8‐0 nylon suture. After the HR returned to control levels, the right CVN was stimulated at the peripheral side of the ligation with bipolar electrodes (10 V at 20 Hz for 10 s). Body temperature was monitored and kept at 37°C using a heating pad during the experiment. After finishing the experiments, the mice were deeply anaesthetized with 5.0% sevoflurane in a plastic chamber, and euthanized by quick decapitation.

The cardiac autonomic activity was assessed using HRV indices, derived from lead II ECG. For recording ECG, firstly, discoid Ag/AgCl electrodes were placed on the subject’s skin after thorough cleaning. These are the most common electrodes used for recording biological signals as it generates low noise level during the recording. Lead II Electrocardiogram (ECG) was then recorded using a computerised 4-channel data acquisition unit (Power lab 26-T, AD instruments, New South Wales, Australia) in sitting position for 5 minutes.

Event-related EDA was recorded, in microsiemens (μS), continuously for the entire duration of the task (at 75 kHz sampling rate using an electrodermal recording unit: ML116 GSR Amp and PowerLab 26T, ADInstruments). Task-relevant events were simultaneously encoded during EDA recording. The electrodes were connected to the palmar surface of the index and ring fingers of the non-dominant hand, and participants were informed to keep this hand stationary during testing.
Amplitude of phasic activity was measured as the difference between the maximum and minimum value of the EDA waveform within an event-related epoch (Wolfram, 2012 ). Within this study, two epochs were used: a post-feedback epoch [response selection onward (4 s)], to examine changes in arousal level after the awareness of trial outcome, and a pre-feedback epoch [From the start cue to response feedback onset (2.4 s window)], to examine changes in arousal level before feedback.