oa Editorial (Thematic Issue: W(e)nt to the Brain: Wnt Signaling in Neurological Disorders)

Evolution rarely ‘designs’ important molecular devices only for one purpose. In fact, the same device is often used in different biological processes. The roles of Wnt signaling clearly illustrate this notion. Although, Wnt signaling has been best known as a master regulator in diverse developmental processes, emerging evidence reveals critical functions of Wnt signaling in the adult nervous system. In this thematic issue of Wnt Signaling in Neurological Disorders, four invited review articles are published. The intention of this collection is to critically assemble and analyze the current knowledge from studies that focus on the roles of Wnt signaling in regulation of the plasticity and function of the adult nervous system, especially in the context of various neurological disorders. The secretion of Wnt protein from neurons is intimately controlled by synaptic activity. This, somewhat, unexpected observation immediately suggests a biological function of Wnt signaling in the adult nervous system. What would secreted Wnt protein do in response to synaptic activation? Evidence for the role of Wnt signaling in synaptic plasticity and glial biology was reviewed by Tang. Some neurological conditions are known to associate with the maladaptive neuronal activity. Given the fact of the regulation of Wnt signaling by synaptic activity, it is natural to expect that Wnt signaling contributes to the pathogenesis of disorders associated with abnormal neuronal activity. As a case in point, Tang also summarized the recent work on the involvement of Wnt signaling in pathological pain, a condition of the hyper-excitation of the pain neural circuitry. Consistent with its role in synaptic plasticity, emerging evidence indicates a regulatory function of Wnt signaling in learning and memory. Abnormalities of the Wnt/β-catenin pathway are associated with the pathology of memory dysfunction in Alzheimer’s Disease (AD). De Ferrari et al. reviewed the recent development in this field, with the focus on the mechanistic implications of aberrant Wnt signaling in different aspects of AD pathologies. In addition to the regulation of memory formation, recent findings suggest an association between Wnt signaling and psychiatric disorders. Peng et al. reviewed the studies on the involvement of Wnt signaling in schizophrenia, while Zhang et al. reviewed work on the contribution of Wnt signaling to autism. Research reviewed in this thematic issue indicates that Wnt signaling is an important regulator of various neurological disorders. Targeting this signaling pathway may lead to the development of novel drugs to treat the disorders.