Preface

Neural connectivity is a topic that describes nerve cells in terms of their anatomical and functional connections. The term connectome refers to a comprehensive map of neural connections, like a wiring diagram of an organism's nervous system. Connectomics, the study of connectomes, can be applied to individual neurons and their synaptic connections, as well as to connections between neuronal populations or to functional and structural connectivity of different brain regions. This book, *Connectivity and Functional Specialization in the Brain*, addresses neural connectivity at these various scales in health and disease.

The chapters review novel findings related to neuroanatomy and cell biology, neurophysiology, neural plasticity, changes of connectivity in neurological disorders, and sensory system connectivity. The book provides the reader with an overview of the current state of the art of research of neural connectivity and focuses on the most important evidence-based developments in this area. Individual chapters focus on recent advances in specific areas of neural connectivity and in different brain regions. All chapters represent recent contributions to the rapidly developing field of neural connectivity.

The book is divided into two sections, each containing three chapters. Section 1 covers "Cellular and Clinical Aspects of Neural Connectivity" and Section 2 contains chapters on "Consciousness and Neural Connectivity".

Chapter One ("Cytokine Profile as a Marker of Cell Damage and Immune Dysfunction after Spinal Cord Injury"), written by G. Telegin, A. Chernov, N. Konovalov, A. Belogurov, I. Balmasova, and A. Gabibov, reviews experimental findings that investigate the role of key cytokines in the formation of a cellular response to trauma. In this case, trauma relates to spinal cord injury. The authors address the specific immunopathogenic interaction of the nervous and immune systems in the immediate and chronic post-traumatic periods.

In Chapter Two ("Blood–Brain Barrier Dysfunction in the Detrimental Brain Function"), Alejandro Gonzalez-Candia, Nicole K. Rogers, and Rodrigo L. Castillo debate the unique characteristics of the blood–brain barrier (BBB) as the interface of blood circulation and neural tissue. The authors discuss the existence of a neurovascular unit (NVU), which emphasizes that the dynamic BBB response to stressors requires coordinated interactions between various central nervous system cell types and structures. This chapter focuses on the structure and function of the BBB and how BBB breakdown causes detrimental brain function.

Chapter Three ("Physical and Cognitive Therapy (PCT) in Critically Ill Patient"), written by Heru Suwardianto, reviews the condition of critically ill patients in the Intensive Care Unit (ICU) who may have impaired physical and cognitive functions. The author aims to show that physical–cognitive therapy benefits physical and cognitive functions in critically ill patients in the ICU.

Chapter Four ("Brain Functional Architecture and Human Understanding"), written by Yan Yufik, addresses the basic question of what it means to understand and contrasts it with learning. The author focuses on different facets of understanding and formulates hypotheses regarding the underlying neuronal mechanisms, attempting to assess their plausibility and reconcile them with recent ideas and findings concerning brain functional architecture.

In Chapter Five ("The Neurofunctional Model of Consciousness: The Physiological Interconnectivity of Brain Networks"), Umberto Leon-Dominguez integrates neural networks' connectivity into a model that explores consciousness and volitional behavior from a neurofunctional perspective. The author proposes a theoretical evidenced-based framework that organizes brain pathways of neural information flow from the ascending reticular activating system and non-specific thalamic nuclei to cortical networks as functional neural loops. According to the author's model, the neural loops act as a global functional neural system, and their disruption due to brain damage can cause catastrophic outcomes, including cognitive and behavioral impairments.

In Chapter Six ("Interplay between Primary Cortical Areas and Crossmodal Plasticity"), Christian Xerri and Yoh'i Zennou-Azogui address a key concept of brain function, namely multisensory interaction and integration. The authors review the literature showing how multimodal interactions between primary cortices can contribute to refining perceptual representations. The authors also discuss how peripheral damage to a sensory system can result in multimodal integration to promote sensory substitution in deprived cortical areas and to favor compensatory plasticity in the spared sensory cortices.

We are grateful to IntechOpen for initiating this book project and for asking us to serve as its editors. Many thanks go to Marijana Francetic at IntechOpen for moving the project ahead in a timely fashion. Thanks are due to all contributors for taking the time to first write a chapter proposal, compose the chapter and, lastly, make our requested revisions to it. Hopefully, all contributors will continue their neural connectivity research with many intellectual challenges and exciting new directions. T.H. would like to thank his wife Dr. Vonnie D.C. Shields, Associate Dean and Professor, Towson University, Towson, MD, and their son Torben Heinbockel for the time that the editor was able to spend working on this book during the past year. Finally, T.H. is grateful to his parents Erich and Renate Heinbockel for their continuous support and interest in his work over many years.
