Learning and memory are believed to depend on plastic changes of neuronal circuits due to activity-dependent potentiation or depression of specific synapses. During the last two decades, plasticity of brain circuits was hypothesized to mainly rely on the flexibility of glutamatergic excitatory synapses, whereas inhibitory synapses were assumed relatively invariant, to ensure stable and reliable control of the neuronal network. As a consequence, while considerable efforts were made to clarify the main mechanisms underlying plasticity at excitatory synapses, the study of the cellular/molecular mechanisms of inhibitory plasticity has received much less attention. Nevertheless, an increasing body of evidence has revealed that inhibitory synapses undergo several types of plasticity at both pre- and postsynaptic levels. Given the crucial role of inhibitory interneurons in shaping network activities, such as generation of oscillations, selection of cell assemblies and signal integration, modifications of the inhibitory synaptic strength represents an extraordinary source of versatility for the fine control of brain states. This versatility also results from the rich diversity of GABAergic neurons in several brain areas, the specific role played by each inhibitory neuron subtype within a given circuit, and the heterogeneity of the properties and modulation of GABAergic synapses formed by specific interneuron classes. The molecular mechanisms underlying the potentiation or depression of inhibitory synapses are now beginning to be unraveled. At the presynaptic level, retrograde synaptic signaling was demonstrated to modulate GABA release, whereas postsynaptic forms of plasticity involve changes in the number/gating properties of GABAA receptors and/or shifts of chloride gradients. In addition, recent research indicates that GABAergic tonic inhibition can also be plastic, adding a further level of complexity to the control of the excitatory/inhibitory balance in the brain. The present Topic will focus on plasticity of GABAergic synapses, with special emphasis on the molecular mechanisms of plasticity induction and/or expression.

The adult brain is not as hard-wired as traditionally thought. By modifying their small- or large-scale morphology, neurons can make new synaptic connections or break existing ones (structural plasticity). Structural changes accompany memory formation and learning, and are induced by neurogenesis, neurodegeneration and brain injury such as stroke. Exploring the role of structural plasticity in the brain can be greatly assisted by mathematical and computational models, as they enable us to bridge the gap between system-level dynamics and lower level cellular and molecular processes. However, most traditional neural network models have fixed neuronal morphologies and a static connectivity pattern, with plasticity merely arising from changes in the strength of existing synapses (synaptic plasticity). In The Rewiring Brain, the editors bring together for the first time contemporary modeling studies that investigate the implications of structural plasticity for brain function and pathology. Starting with an experimental background on structural plasticity in the adult brain, the book covers computational studies on homeostatic structural plasticity, the impact of structural plasticity on cognition and cortical connectivity, the interaction between synaptic and structural plasticity, neurogenesis-related structural plasticity, and structural plasticity in neurological disorders. Structural plasticity adds a whole new dimension to brain plasticity, and The Rewiring Brain shows how computational approaches may help to gain a better understanding of the full adaptive potential of the adult brain. The book is written for both computational and experimental neuroscientists. Reviews the current state of knowledge of structural plasticity in the adult brain Gives a comprehensive overview of computational studies on structural plasticity Provides insights into the potential driving forces of structural plasticity and the functional implications of structural plasticity for learning and memory Serves as inspiration for developing novel treatment strategies for stimulating functional repair after brain damage

Drugs of abuse induce a host of alterations in brain structure and function, ranging from changes in gene expression and epigenetic processes to aberrant synaptic plasticity to volumetric changes in discrete brain regions. These alterations can be drug class-specific, and are not confined to neurons, as drugs of abuse also induce molecular and cellular alterations in various glial cell types such as astrocytes and microglia. The phenomenon of drug-induced plasticity includes changes in dendritic branching and architecture, dendritic spine density and morphology, astrocyte-neuronal interactions, dysregulation of glutamatergic and GABAergic signaling, and alterations in myelination or microglial phenotype. This drug-induced "rewiring" of the brain at numerous levels can contribute to the development, maintenance, and persistence of the addicted state, as well as associated deficits in normal cognitive functioning. The aim of this Research Topic is to collect recent and important findings related to the structural alterations produced by drug of abuse in neurons, glial, and other cell types of the central nervous system.

This volume brings together authors working on a wide range of topics to provide an up to date account of the underlying mechanisms and functions of neurogenesis and synaptogenesis in the adult brain. With an increasing understanding of the role of neurogenesis and synaptogenesis it is possible to envisage improvements or novel treatments for a number of diseases and the possibility of harnessing these phenomena to reduce the impact of ageing and to provide mechanisms to repair the brain.

Neurogenesis in the adult brain has emerged as one of the most dynamic and rapidly moving fields in modern neuroscience research. The implications of adult neurogenesis for health and well-being are wide-ranging, with findings in this area having distinct relevance for treatment and rehabilitation in neurology and psychopathology. Adult Neurogenesis in the Hippocampus addresses these implications by providing an up-to-date account on how neurogenesis in the adult hippocampus contributes to critical psychological and physiological processes, such as learning and memory, and how it is modified by life experiences, such as aging, environmental enrichment, exercise, and dieting. The book also provides the most current reviews of how adult hippocampal neurogenesis influences the pathogenesis of mood disorders, addiction, and key neurological disorders. This book is the ideal resource for researchers and advanced graduates seeking focused knowledge on the role of adult neurogenesis in brain health and disease. Provides a unique overview of how adult hippocampal neurogenesis contributes to adaptive processes, brain psychopathology, and disease Includes state-of-the-art reviews by leading world experts in adult neurogenesis

Traumatic brain injury (TBI) remains a significant source of death and permanent disability, contributing to nearly one-third of all injury related deaths in the United States and exacting a profound personal and economic toll. Despite the increased resources that have recently been brought to bear to improve our understanding of TBI, the developme