Final answer:
Monopolar stimulation's active electrode is determined by the polarity of the electric field. Specific ion channels' response to stimuli, such as hyperpolarization, is relevant when applying this technique to neural tissue.
Step-by-step explanation:
The parameter that determines which electrode(s) will be active in monopolar stimulation is the polarity of the electric field created between the electrodes. In this context, an active electrode is one that is actively involved in stimulating the tissue, while the dispersive electrode serves as a reference or ground. The active electrode will usually be smaller and more focused, providing the desired stimulation to the target tissue. This is influenced by the configuration of the electrical circuit and the characteristics of the electrodes themselves. The ion channels within the cell membrane respond differently to electrical stimuli. Some stimuli result in hyperpolarization, which depends on the activation of specific ion channels, which may be relevant to the operation of monopolar stimulation when it is applied to neural tissue. Electrocardiograms (ECGs) are a practical example of how monopolar configurations can capture electrical activity, as ECGs measure the small electric signals generated by the heart. Similarly, transcranial magnetic stimulation (TMS) uses electric fields to influence the electrical activity in the brain for therapeutic purposes.