New neurotechnologies for modulating brain functions are becoming increasingly powerful and applicable to diverse diseases, but raise new questions for clinicians, ethicists, policy makers, and laymen. This issue of Brain Topography gathers several papers exploring the clinical and ethical implications of several invasive and noninvasive neuromodulation approaches. The opportunities and challenges associated with the emergence of neuro-engineering solutions to brain research and brain repair require a close dialogue between multiple disciplines, as well as open discussion with the general public.