This review synthesizes evidence on how direct current and alternating current electrical stimulation affect neurons and glia in the central nervous system, spanning basic research and clinical translation. It reports polarity- and parameter-dependent effects on axonal growth, along with immunomodulatory glial responses that may favor regeneration and enhanced myelination via OPC differentiation. The authors note early clinical applications with potential longer-term functional improvements, while emphasizing that stimulation parameters and patient context can influence risks and benefits.