Inhibitory interneurons are thought to play a crucial role in several features of neocortical processing, including dynamics on the timescale of milliseconds. Their anatomical and physiological characteristics are diverse, suggesting that different types regulate distinct aspects of neocortical dynamics. Interneurons expressing parvalbumin (PV) and somatostatin (SOM) form two non-overlapping populations. Here, I describe computational, correlational (neurophysiological) and causal (optogenetic) studies testing the role of PV and SOM neurons in dynamic regulation of sensory processing. First, by combining extra- and intracellular recordings with optogenetic and sensory stimulation and pharmacology, we have shown that PV cells play a key role in the generation of neocortical gamma oscillations, confirming the predictions of prior theoretical and correlative studies. Following this experimental study, we used a biophysically plausible model, simulating thousands of neurons, to explore mechanisms by which these gamma oscillations shape sensory responses, and how such transformations impact signal relay to downstream neocortical areas. We found that the local increase in spike synchrony of sensory-driven responses, which occurs without decreasing spike rate, can be explained by pre- and post-stimulus inhibition acting on pyramidal and PV cells. This transformation led to increased activity downstream, constituting an increase in gain between the two regions. This putative benefit of PV-mediated inhibition for signal transmission is only realized if the strength and timing of inhibition in the downstream area is matched to the upstream source. Second, we tested the hypothesis that SOM cells impact a distinct form of dynamics, sensory adaptation, using intracellular recordings, optogenetics and sensory stimulation. In resting neocortex, we found that SOM cell activation generated inhibition in pyramidal neurons that matched that seen in in-vitro studies. Optical SOM cell activation also transformed sensory-driven responses, decreasing evoked activity. In adapted responses, optical SOM cell inactivation relieved the impact of sustained sensory input, leading to increased membrane potential and spike rate. In contrast, SOM cell inactivation had minimal impact on sensory responses in a non-adapted neocortex, supporting the prediction that this class of interneurons is only recruited when the network is in an activated state. These findings present a previously unappreciated mechanism controlling sensory adaptation.

Jasper's Basic Mechanisms, Fourth Edition, is the newest most ambitious and now clinically relevant publishing project to build on the four-decade legacy of the Jasper's series. In keeping with the original goal of searching for "a better understanding of the epilepsies and rational methods of prevention and treatment.", the book represents an encyclopedic compendium neurobiological mechanisms of seizures, epileptogenesis, epilepsy genetics and comordid conditions. Of practical importance to the clinician, and new to this edition are disease mechanisms of genetic epilepsies and therapeutic approaches, ranging from novel antiepileptic drug targets to cell and gene therapies.

This book has brought together leading investigators who work in the new arena of brain connectomics. This includes ‘macro-connectome’ efforts to comprehensively chart long-distance pathways and functional networks; ‘micro-connectome’ efforts to identify every neuron, axon, dendrite, synapse, and glial process within restricted brain regions; and ‘meso-connectome’ efforts to systematically map both local and long-distance connections using anatomical tracers. This book highlights cutting-edge methods that can accelerate progress in elucidating static ‘hard-wired’ circuits of the brain as well as dynamic interactions that are vital for brain function. The power of connectomic approaches in characterizing abnormal circuits in the many brain disorders that afflict humankind is considered. Experts in computational neuroscience and network theory provide perspectives needed for synthesizing across different scales in space and time. Altogether, this book provides an integrated view of the challenges and opportunities in deciphering brain circuits in health and disease.

This book brings together leading investigators who represent various aspects of brain dynamics with the goal of presenting state-of-the-art current progress and address future developments. The individual chapters cover several fascinating facets of contemporary neuroscience from elementary computation of neurons, mesoscopic network oscillations, internally generated assembly sequences in the service of cognition, large-scale neuronal interactions within and across systems, the impact of sleep on cognition, memory, motor-sensory integration, spatial navigation, large-scale computation and consciousness. Each of these topics require appropriate levels of analyses with sufficiently high temporal and spatial resolution of neuronal activity in both local and global networks, supplemented by models and theories to explain how different levels of brain dynamics interact with each other and how the failure of such interactions results in neurologic and mental disease. While such complex questions cannot be answered exhaustively by a dozen or so chapters, this volume offers a nice synthesis of current thinking and work-in-progress on micro-, meso- and macro- dynamics of the brain.

This book reviews recent progress in cortical development research, focusing on the mechanisms of neural stem cell regulation, neuronal diversity and connectivity formation, and neocortical organization. Development of the cerebral cortex, the center for higher brain functions such as cognition, memory, and decision making, is one of the major targets of current research. The cerebral cortex is divided into many areas, including motor, sensory, and visual cortices, each of which consists of six layers containing a variety of neurons with different activities and connections. As this book explains, such diversity in neuronal types and connections is generated at various levels. First, neural stem cells change their competency over time, giving sequential rise to distinct types of neurons and glial cells: initially deep layer neurons, then superficial layer neurons, and lastly astrocytes. The activities and connections of neurons are further modulated via interactions with other brain regions, such as the thalamocortical circuit, and via input from the environment. This book on cortical development is essential reading for students, postdocs, and neurobiologists.

Atlas of the Developing Mouse Brain, Second Edition builds on the features of successful first edition, providing a comprehensive and convenient reference for all areas of the mouse brain at Fetal-Day 17.5 (E17.5), Day-of-Birth (P0), and Day-Six postnatal (P6). The book also delineates the parts of the eye, features of the skull, ganglia, nerves, arteries, veins, bones and foramina. This atlas is an essential tool for researchers and students who study the development of the mouse brain, or for those who interpret findings from genetic manipulation. - Contains 176 high-resolution color scans of Nissl-stained coronal sections of the brain and skull of the fetal (E17.5), day-of-birth (P0), and day-six postnatal mouse (P6) - Includes diagrams that delineate all structures of the brain, as well as peripheral nerves, ganglia, muscles, bones, veins and arteries of the head - Presents approximately 5000 corrections and updates from the first edition - Includes color codes of the veins, arteries, nerves and ganglions of the skull in diagrams

In order to focus on principles, each chapter in this work is brief, organized around 1-3 wiring diagrams of the key circuits, with several pages of text that distil the functional significance of each microcircuit

The authoritative reference on NEURON, the simulation environment for modeling biological neurons and neural networks that enjoys wide use in the experimental and computational neuroscience communities. This book shows how to use NEURON to construct and apply empirically based models. Written primarily for neuroscience investigators, teachers, and students, it assumes no previous knowledge of computer programming or numerical methods. Readers with a background in the physical sciences or mathematics, who have some knowledge about brain cells and circuits and are interested in computational modeling, will also find it helpful. The NEURON Book covers material that ranges from the inner workings of this program, to practical considerations involved in specifying the anatomical and biophysical properties that are to be represented in models. It uses a problem-solving approach, with many working examples that readers can try for themselves.