Signagel

The EEG recording was conducted while the participants processed the arithmetic and working memory tasks in a separate, normally lit and quiet room, using a 64-channel BioSemi ActiveTwo EEG system (BioSemi, Amsterdam, Netherlands). Electrodes were mounted according to the 10:20 system (Jasper, 1958 ) using BioSemi head caps and Signagel (Parker Laboratories, Fairfield, USA) to ensure appropriate contact. As the tDCS electrodes were mounted at the positions F3, P3, Fp2, and AF8 these EEG electrodes were not mounted.

Twenty-four New Zealand rabbits of both sexes (10 males), weighing between 1.8 and 2.4 kg, were utilized for this study. The animal preparation procedure was similar to that of our previous study^{25 (link)}. The animals were anaesthetized via ear vein injection of sodium pentobarbital at a dose of 30 mg/kg and placed on a surgical board in the supine position. After intubation with an 11-gauge cannula, the animals were mechanically ventilated with room air at a tidal volume of 0.60 mL/100 g (ALC-V8, Alcott Biotech Co. Ltd, Shanghai, China). A PE-160 catheter was inserted into the surgically exposed right femoral artery to measure arterial pressure. A 5F bipolar pacing catheter (St. Jude Medical, Minnetonka MN, USA) was advanced from the right external jugular vein into the right ventricle to induce VF. Three needle electrodes were applied to the right upper, left upper, and lower limbs to record the electrocardiogram (ECG). A pair of external defibrillation pads with a diameter of 40 mm was fixed on the chest, with the positive pad placed on the right side and the negative pad placed on the left side, so that the heart was directly interposed between the two pads. An electrically conductive adhesive gel (SIGNA GEL, Parker Laboratories Inc, Fairfield, NJ, USA) was interposed between the pads and the skin to ensure close contact.

SCRs were recorded at 200 hz throughout testing via two surface cup electrodes (Ag-AgCl, 8 mm diameter, Biopac model EL258-RT, Goleta, CA) filled with electrolyte gel (Signa Gel, Parker laboratories Fairfield, NJ) attached to the bottom of the participants left foot, approximately 2 cm apart. We sampled SCL during the CS period, and the preceding two second baseline. Values were converted to a percent change from the baseline, and the maximum value during the CS period was used to indicate the response magnitude.