- Creatine: Cheap Ergogenic Supplement with Great Potential for Health and Disease -- Early Evolution of the Creatine Kinase Gene Family and the Capacity for Creatine Biosynthesis and Membrane Transport -- The Creatine Kinase Phosphotransfer Network: Thermodynamic and Kinetic Considerations, the Impact of the Mitochondrial Outer Membrane and Modelling Approaches -- Expression and Function of Agat, Gamt and CT1 in the Mammalian Brain -- A Novel Relationship Between Creatine Transport at the Blood-Brain and Blood-Retinal Barriers, Creatine Biosynthesis, And its Use for Brain and Retinal Energy Homeostasis -- Functional Insights into the Creatine Transporter -- In Vivo Magnetic Resonance Spectroscopy of Transgenic Mice with Altered Expression of Guanidinoacetate Methyltransferase and Creatine Kinase Isoenzymes -- Cerebral Creatine Deficiency Syndromes: Clinical Aspects, Treatment and Pathophysiology -- Pre-Symptomatic Treatment of Creatine Biosynthesis Defects -- Clinical Use of Creatine in Neuromuscular and Neurometabolic Disorders -- The Neuroprotective Role of Creatine -- Ergogenic Effects of Creatine in Sports and Rehabilitation -- Pharmacokinetics of Creatine -- Safety of Creatine Supplementation -- Creatine - its Chemical Synthesis, Chemistry, and Legal Status -- Creatine and Creatine Kinase in Health and Disease - A Bright Future Ahead?. Although creatine was discovered already in the 1830s, it is only in recent years that its crucial role for human health and general well-being has been increasingly realized and appreciated. A number of beneficial health effects have been ascribed to oral creatine supplementation, such as neuroprotective, ergogenic, anti-diabetic, anti-inflammatory, antiviral, or antitumor effects. Creatine may even improve memory and intelligence. In the present book, emphasis is placed on the intricate interplay between creatine and creatine kinase function on one hand, and proper brain function, neurodegenerative disease and/or neuroprotection on the other hand. The book also elaborates on the recently identified inborn errors of creatine biosynthesis and transport, the so-called cerebral creatine deficiency syndromes. The clinical hallmarks of these disorders are mental retardation, epilepsy, autistic-like behaviour, and speech and language delay. In addition, the muscle growth- and strength-promoting effects, the pharmacokinetics and the safety of oral creatine supplementation are discussed. Finally, the present book outlines the emerging "systems biology" approaches for understanding the pleiotropic effects of creatine and creatine kinase, and hypothesizes on the most promising and influential future avenues of research towards creatine-based nutritional strategies for the prevention of neurological disease, and for improving the quality of life in general.