Electrode Placement to Record Neuromuscular Function in Rat Diaphragm Muscle

To begin, position the anesthetized and prepared rat for compound muscle action potential recording. Place the active needle electrode subcutaneously over the midclavicular line, inferior to the last rib border. Then, position the reference needle electrode subcutaneously at the angle between the xiphoid process and the last sternocostal cartilage.

Next, use a pair of 28-gauge monopolar needle electrodes for phrenic nerve stimulation at the carotid sheath. Place the electrode subcutaneously on the lateral neck between the anterior and middle scalene muscles, with a separation of about one centimeter. Confirm that the placement of the stimulating needles is at the level below the fourth cervical vertebrae.

Then, place a disposable surface electrode on the tail for the ground electrode.