Interactions between the Autonomic Nervous System and the Immune System after Stroke

Acute stroke is one of the leading causes of morbidity and mortality worldwide. Stroke‐induced immune‐inflammatory response occurs in the perilesion areas and the periphery. Although stroke‐induced immunosuppression may alleviate brain injury, it hinders brain repair as the immune‐inflammatory response plays a bidirectional role after acute stroke. Furthermore, suppression of the systemic immune‐inflammatory response increases the risk of life‐threatening systemic bacterial infections after acute stroke. Therefore, it is essential to explore the mechanisms that underlie the stroke‐induced immune‐inflammatory response. Autonomic nervous system (ANS) activation is critical for regulating the local and systemic immune‐inflammatory responses and may influence the prognosis of acute stroke. We review the changes in the sympathetic and parasympathetic nervous systems and their influence on the immune‐inflammatory response after stroke. Importantly, this article summarizes the mechanisms on how ANS regulates the immune‐inflammatory response through neurotransmitters and their receptors in immunocytes and immune organs after stroke. To facilitate translational research, we also discuss the promising therapeutic approaches modulating the activation of the ANS or the immune‐inflammatory response to promote neurologic recovery after stroke.