What effect does anodal transcranial direct current stimulation (tDCS) have on neural excitability?

Anodal transcranial direct current stimulation (tDCS) is known for its specific effects on neuronal excitability. When anodal stimulation is applied, it typically leads to an increase in the excitability of neurons in the area being stimulated. This is believed to occur because the positive current provided by the anode promotes the depolarization of neuronal membranes, which lowers the threshold for action potentials. As a result, neurons become more responsive to synaptic inputs, effectively increasing their likelihood of firing. This increase in excitability can have various applications, such as enhancing learning and memory processes or improving motor functions in various therapeutic contexts.

In contrast, other forms of stimulation, such as cathodal stimulation, would lead to decreased excitability, and some possible responses could indicate no effect or instability, but these do not accurately describe the consistent outcomes associated with anodal tDCS. Thus, the choice indicating an increase in neural excitability directly aligns with what is observed in research on the effects of anodal tDCS.