oa Editorial [Hot Topic: New Mechanisms of Neuronal Injury and Neuroprotection (Guest Editor: Weihai Ying)]

New Mechanisms of Neuronal Injury and Neuroprotection Neurological diseases, including such devastating illnesses as stroke, Alzheimer's disease, Parkinson's disease, epilepsy, traumatic brain injury and brain tumors, belong to the major diseases that have caused the greatest number of death and disability around the world. A large number of studies have exposed many mechanisms of the illnesses. However, our understanding regarding the diseases is still significantly deficient, and effective therapies are absent for most of the illnesses. For example, over one hundred clinical trials on drug treatment of stroke have failed in the recent years. There may be multiple reasons underlying the numerous failures in developing effective therapies for treating neurological diseases: 1) Our understanding regarding the pathology of neurological diseases is still far from complete; 2) a major portion of our understanding on the mechanisms of neurological diseases has come from the studies using animal models of the diseases; however, there could be significant differences between the pathology of certain neurological diseases and that of the animal models of the diseases; and 3) the blood-brain barriers (BBB) constitute a major barrier for most drugs to enter the brain. Considering that the brain may be one of the most complex systems that have evolved in the universe, it is not unexpected that we have not had sufficient knowledge and capacity to conquer the devastating threats that are produced by neurological diseases. However, we can be reasonably optimistic that the rapid development of science and technology of human being would enable us to eventually conquer the seemingly intractable neurological diseases in the future. To overcome the critical obstacles in our long march toward the cure of neurological illnesses, future studies in the following directions may be of particular significance: 1) To strengthen translational studies on neurological diseases, by increasing the number of clinical trials on the therapeutic effects of new treatment strategies and by increasing studies on the pathological changes of the patients of neurological diseases; 2) to enhance the studies on novel therapeutic strategies, such as stem cell therapy, for treating neurological diseases; 3) to increase the studies on new strategies to enhance the drug delivery across the BBB to enter the brain; and 4) to increase the applications of interdisciplinary approaches, particularly medical imaging techniques and nanotechnology, to improve the diagnosis and monitoring of the illnesses. In order to establish new effective therapeutic strategies for neurological diseases, it is pivotal to further investigate the mechanisms underlying the etiology and pathology of the illnesses. A renowned Chinese expression is: ‘Reviewing what you have learned is essential for you to learn new things’. In this special issue, multiple important topics regarding neurological diseases are reviewed. Several reviews have focused on the promising specific therapeutic targets for neurological diseases: The review of Cairns et al. provides a comprehensive overview of the roles of NADPH oxidase in ischemic brain damage; Chu et al. have reviewed the current advances regarding the mechanisms underlying the roles of acid-sensing ion channels (ASICs) in neurological disorders; Xia et al. provides an overview regarding the roles of opiod receptors as a treatment target for neurological diseases; Shao et al. have reviewed the advances regarding the roles of estrogen and estrogen receptors in neurological diseases; the article of Ma et al. provides an overview of the roles of NAD+ and NAD+-dependent enzymes in neurological diseases as well as the potential of these factors as therapeutic targets; Wang et al. have reviewed the information regarding the roles of chemokine CXCL12 and its receptors in ischemic stroke; and Li et al. provides an overview of the recent progress regarding the participation of synaptic and extrasynaptic NMDA receptors in multiple neurologic diseases. There are also a few reviews regarding the general therapeutic strategies for neurological diseases: The article of Dornbos and Ding provides an overview regarding the mechanisms underlying the neuroprotective effects of exercises; the review of Liu et al. provides an overview of the roles of protein aggregation in neurological diseases; and the review of Zhao provides an overview of the protective mechanisms underlying post-conditioning. I would like to express my sincere gratitude to the authors of the reviews in this special edition for their excellent work. I would also like to thank the Assistant Editor of this issue --- Dr. Weiliang Xia of Med-X Research Institute, Shanghai Jiao Tong University --- for his careful editing work. I would also like to express my gratitude to the editorial assistants of this special issue, Ms. Yingxin Ma and Mr. Heyu Chen, for their valuable editorial support.....