This book consolidates the current knowledge of how short and long-duration spaceflight affects the anatomy and physiology of the central nervous system. It also incorporates the methodology and constraints of studying the central nervous system in space. Chapters detail advances in imaging techniques available to assess intracranial and intraocular pathology as well as translational medicine with an emphasis on brain cancer and neurodegenerative disease in spaceflight. Additionally, the book offers theoretical background information, tested laboratory protocols, and step-by-step methods for reproducible lab experiments to aid neuroscientists and neurobiologists in laboratory testing and experimentation. Spaceflight and the Central Nervous System is the first to comprehensively include all aspects of spaceflight-induced changes in the central nervous system. It is an invaluable resource for basic and clinical laboratory trainees and researchers in aerospace medicine and physiology or for those looking to gain specific knowledge in spaceflight neuroscience.

Although once a widely speculated about and largely theoretical topic, spaceflightinduced intracranial hypertension is more accepted as a distinct clinical phenomenon; yet, the underlying physiological mechanisms are still poorly understood. In the past, many terms were used to describe the symptoms of malaise, nausea, vomiting, and vertigo though longer duration spaceflights have increased the prevalence of overlapping symptoms of headache and visual disturbance. Spaceflight-induced visual pathology is thought to be a manifestation of increased intracranial pressure (ICP) because of its similar presentation to cases of known intracranial hypertension on Earth as well as the documentation of increased ICP by lumbar puncture in symptomatic astronauts upon return to gravity. The most likely mechanisms of spaceflight-induced increased ICP include a cephalad shift of body fluids, venous outflow obstruction, blood-brain barrier breakdown, and disruption to CSF flow. The relative contribution of increased ICP to the symptoms experienced during spaceflight is currently unknown though as other factors recently posited to contribute include local effects on ocular structures, individual differences in metabolism, and the vasodilator effects of carbon dioxide. Spaceflight-induced intracranial hypertension must be distinguished from other pathologies with similar symptomatology. The following chapter discusses the proposed physiologic causes and the pathological manifestations of increased ICP in the spaceflight environment and provides considerations for future long-term space travel.