Postoperative cognitive dysfunction (POCD) is a common central nervous system complication after anesthesia and surgery. Symptoms include mental disorder, anxiety, personality changes, and memory impairment. It may last for days, months, or even years and is associated with productivity losses in the workforce. A few patients may develop irreversible cognitive impairment or dementia after POCD. It can even increase morbidity and mortality. Compared with patients without POCD, the one-year mortality of patients with POCD increases by 8.5%. According to the literature, the occurrence of POCD varies widely from 9% to 60%, due to differences in study populations and protocols used to detect POCD. For example, patients undergoing noncardiac surgery have a 25.8% chance of developing POCD in the first week after surgery, and 9.9% within three months. For patients undergoing coronary artery bypass grafting, the incidence of POCD is 53% after one week, 24% at six months after operation and 42% after five years. Aging is considered the only definite risk factor of POCD, however, the reason why elderly patients are more vulnerable to memory deficits after surgery are being debated.

The current challenges that remain in the POCD field include, but are not limited to, the exact role of neuroinflammation in POCD, the prevention strategies of POCD during anesthesia/surgery, as well as finding new therapeutic targets. Recently, there has been a surge in efforts to discover potential mechanisms of POCD, such as neuroinflammation of the central nervous system, central cholinergic system dysfunction, synaptic dysfunction, the gut-brain axis, etc. However, the pathogenesis of POCD is still unclear.

The goal of this Special Issue is to bring together investigators who study the underlying mechanisms of POCD. The aims of this Special Issue are to provide an overview of POCD research in recent years (including research trends, hotspots, etc.), and to highlight neuroscience-oriented preclinical research of the underlying mechanisms of POCD and also clinical research, including epidemiology, diagnosis, prevention, complication management and future solutions of POCD. Work related to the occurrence, development, and maintenance of POCD is also welcome. We encourage investigators to summarize their current opinions and research hotspots on the topic of POCD and to provide their own thoughts. We especially welcome researchers who present pre-clinical work of their innovative ideas about POCD and who can point towards potential therapy targets. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• POCD and neuroinflammation in the central nervous system – new insights into the role of neuroinflammation in the occurrence and development of POCD, and potential molecular therapy targets of POCD
• The role of glial cells in POCD, including but not limited to, the morphological and functional changes of glial cells during the development of POCD, functional interactions between glial cells and neurons, etc.
• POCD and the gut-brain axis – changes in the composition and function of gut bacteria after anesthesia and surgery and whether they are associated with POCD
• Analyzing the structure and function of neuronal circuits or micro circuits in POCD
• All types of clinical studies relating to the occurrence, development, prevention, and management of POCD, especially well-designed prospective randomized controlled trials