Preface

Scientific advances are products of the intellectual human effort and a creative activity directed at obtaining knowledge. From the legacy of Ionian culture more than 2000 years ago, with the exception of a long period of interruption that ended with the Renaissance, knowledge based on experimental approaches accumulated such that the ability of humans to store and understand all of the information they receive is almost impossible. The divisions of the sciences thus emerge as exact sciences that comprise social sciences, humanities, and many other disciplines. Is there such a thing as an inexact science? Maybe. But perhaps it is not science. The neurosciences are no exception, denoted by the plural use of the word. Why not conceive neuronal science and behavioral science as a whole? Any division is artificial because functional and even pathological events occur simultaneously in organisms that have evolved with the development of a nervous system. Organisms, in turn, are simultaneously influenced by environmental, social, and cultural phenomena. Therefore, when the aim is to understand the functional processes of the nervous system, attempting to integrate knowledge from several points of view is necessary, eliminating some of the artificial frontiers constructed in the first half of the 20th century and incorporating as many sources of knowledge as possible into the science of the nervous system and behavior. There in one main goal: to understand the natural laws of nervous system function. We cannot invent these laws. They already exist, but we want to identify their rules of operation. The first scientists called themselves "Physiologists." They purported to know how things and the universe work. The authors of the chapters in this book can also be considered physiologists. From different points of view, they attempt to understand the operation of the nervous system under conditions of both health and illness.

The diverse topics contained in this book are grouped by several aspects, from the phenomena that underlie neuronal communication and signaling to how the first affective linkages are established between mammals. In the chapters that deal with homeostatic processes, inflammation is a central topic. Inflammation has long been considered a restorative process that follows trauma, but pain may also be considered an inseparable partner of inflammation that serves as a danger signal. Alcoholism is the most frequently abused, legal drug. To date, its physiopathology is only partially understood. Lastly, around the second half of the 20th century, medical students

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learned little about chronic degenerative illnesses and the processes that underlie learning and memory. Certainly, human longevity has increased, increasing the prevalence of previously scarce illnesses that affect memory. Unsurprising is the incidence of people who suffer from Parkinson's disease and Alzheimer's disease, illnesses that typically affect individuals in their sixth decade of life. Today, octogenarians are common. The reasonable goal of humans is to live as many healthy years as possible, with the functional cognitive capacity and autonomy to leave this world without becoming a nuisance and endure as little suffering as possible. The venerable old man and woman in antiquity often became a considerable charge for their family when they became ill. It is better to become grandfathers and grandmothers who recount stories, provide advice and orientation, and generously share their experiences every day. But such a life is only possible if one is healthy.

Common denominators of the chapters in this book are the ancient concept of physiology and natural selection. All species possess some form of organization of the nervous system, from coelenterates to mammals, and they have inhabited this planet for thousands or even millions of years. But the natural laws that permit adaptation and survival are only partially known. All of the chapters in this book make contributions in this sense. As scientists, we search for the rules that govern the natural strategies that allow individuals and the species to survive from the viewpoint of the science of the nervous system, unencumbered by frontiers.

> **Dr. Carlos M. Contreras** Biomedical Research Institute, National Autonomous University of Mexico, at Unit Xalapa, Neuroethology Institute, University of Veracruz, Mexico
