Immunity in neuromodulation: probing neural and immune pathways in brain disorders

Immunity finely regulates brain function. It is directly involved in the pathological processes of neurodegenerative diseases such as Parkinson's and Alzheimer's disease, post-stroke conditions, multiple sclerosis, traumatic brain injury, and psychiatric disorders (mood disorders, major depressive disorder (MDD), anxiety disorders, psychosis disorders and schizophrenia, and neurodevelopmental disorders (NDD)). Neuromodulation is currently a leading therapeutic strategy for the treatment of these disorders, but little is yet known about its immune impact on neuronal function and its precise beneficial or harmful consequences. We review relevant clinical and preclinical studies and identify several specific immune modifications. These data not only provide insights into how neuromodulation acts to optimize immune-brain interactions, but also pave the way for a better understanding of these interactions in pathological processes.