When the projected volumes of the Handbook are completed, most of our current knowledge of the biochemistry of nervous systems will have been touched upon. A number of the chapters will have dealt with the correlations of the biochemical findings with morphological and physio logical parameters as well. Considering the abysmal lack of such attempts, even in the recent past, this is a sign of great progress. If the reader's eventual goal is to derive the "laws" that relate various aspects of animal and human behavior to underlying physiological and biochemical function, these admirable volumes will help him to establish a firm biochemical base from which to operate. It is certain that the future approaches to the various problems of the information-processing functions of the nervous system will require an integrated understanding of the essence of all of the scientific disciplines which are grouped under the general name of neuro biology. The rich feast of information offered up in this Handbook will enable those in the non-chemical disciplines to pick and choose those areas of chemical information pertinent to their immediate interests. Similar types of compendia by physiologists, anatomists, cyberneticists, and psychologists have been helpful to chemists and continue to be so.

Anyone who has any contact with mental patients, old or young, or their families, or just visits a mental hospital or school for the retarded, is aware of the tremendous suffering caused by malfunctioning of the brain. The func tion of no other organ is so crucial for our everyday life, our proper func tioning, indeed our happiness, and no other illness causes as much anguish to patients or their families as mental illness. It is surprising and sad, therefore, how little effort has been devoted to research in this area; more so because such research is the only hope to ameliorate this suffering, or, to speak in the language of politics or economics, to decrease the enormous sums that we spend on trying to help our patients, with what is must generally be agreed are the most primitive and inadequate methods of treatment. Clearly, since functions of the brain are vital not only in illness, but in health, pathology is not the only area of concern to neurochemists, but it is an area that urgently needs neurochemical contributions. Progress in this field has been slower than in other areas of neurochemistry, and it seems that solutions in this field are very elusive. The reason for this is that the experimental approach is especially difficult in conditions specific for humans, or specific for complex behavior.

Volume V deals with the problems of turnover in the nervous system. "Turnover" is defined in different ways, and the term is used in different contexts. It is used rather broadly in the present volume, and intentionally so. The turnover of macromolecules is only one aspect; here "turnover" in dicates the simultaneous and coordinated formation and breakdown of macromolecular species. The complexities of cerebral protein turnover are shown in a separate chapter dealing with the synthesis of proteins, in another on breakdown, and in still another on the relationship of these two (showing how the two halves of turnover are controlled). The fact that most likely the two halves of protein turnover, synthesis and breakdown, are separated spatially and the mechanisms involved are different further emphasizes the complexity of macromolecular turnover. "Turnover" is used in a different context when the turnover of a cycle is discussed; but here again a number of complex metabolic reactions have to be interrelated and controlled; some such cycles are discussed briefly in this volume, additional cycles have been discussed with metabolism, and some cycles still await elucidation or discovery.

That chemicals (although not always called by this name) affect the brain and its functions, such as behavior, has been known for thousands of years. It is therefore surprising that the concept that chemical mechanisms are at least partially responsible for the complex functions of the brain is so recent. Investigation of the closely interlinked biophysical and biochemical proper ties of the nervous system has achieved many notable successes in recent years and is the most exciting development in 20th-century science. Although all the morphology, the activity, and the alteration of the brain, whether bioelectric, biochemical, pathological, or structural, constitute an organic and indivisible whole, the ambition of the Handbook is to look at only a few aspects of this whole and to focus the discussions on the experi ments that the neurochemists have performed. Neurochemical study of the nervous system has, perhaps of necessity, gone through several phases: the first phase was more analytical and in volved study of the composition of the tissue; the second, more recent phase clarified many of the metabolic sequences that occur in this tissue. Clearly, both were essential, but they showed that additional approaches are neces sary. The present phase seems to be the study of control processes; present interest focuses on what determines, in a qualitative and quantitative fashion, the processes occurring in the nervous system. Perhaps the next phase will be the study of function, the study of the final stage of integration.

Volume V deals with the problems of turnover in the nervous system. "Turnover" is defined in different ways, and the term is used in different contexts. It is used rather broadly in the present volume, and intentionally so. The turnover of macromolecules is only one aspect; here "turnover" in dicates the simultaneous and coordinated formation and breakdown of macromolecular species. The complexities of cerebral protein turnover are shown in aseparate chapter dealing with the synthesis ofproteins, in another on breakdown, and in still another on the relationship ofthese two (showing how the two halves of turnover are controlled). The fact that most likely the two halves of protein turnover, synthesis and breakdown, are separated spatially and the mechanisms involved are different further emphasizes the complexity of macromolecular turnover. "Turnover" is used in a different context when the turnover of a cycle is discussed; but he re again a number of complex metabolic reactions have to be interrelated and controlled; some such cycles are discussed briefly in this volume, additional cycles have been discussed with metabolism, and some cycles still await elucidation or discovery.

The explosive accumulation of new knowledge in the biological sciences in the last decades has advanced our understanding of the basic mechanisms that underlie most biological phenomena. These advances, however, have not been uniform but have varied considerably among the different biological problems. In some cases, e.g., biochemical genetics, radical advances have been made which have changed our ideas and our approaches. In other cases, even with work which has yielded much detailed new knowledge, our under standing of basic mechanisms remains very inadequate. Among the lines of work that have not yet led to dramatic conceptual advances is the problem of control of biological activities. This problem is, of course, basic both to any full understanding of life as a whole, and to any real understanding of its most minute phenomena. Indeed, the myriad of biological activities that we can observe by direct or indirect means are all under the sway of most exquisitely precise mechanisms. Any malfunctioning of these mechanisms has serious consequences, not only for the particular function itself, but for all the related and interlinked activities.

How we raise young children is one of today's most highly personalized and sharply politicized issues, in part because each of us can claim some level of "expertise." The debate has intensified as discoveries about our development-in the womb and in the first months and years-have reached the popular media. How can we use our burgeoning knowledge to assure the well-being of all young children, for their own sake as well as for the sake of our nation? Drawing from new findings, this book presents important conclusions about nature-versus-nurture, the impact of being born into a working family, the effect of politics on programs for children, the costs and benefits of intervention, and other issues. The committee issues a series of challenges to decision makers regarding the quality of child care, issues of racial and ethnic diversity, the integration of children's cognitive and emotional development, and more. Authoritative yet accessible, From Neurons to Neighborhoods presents the evidence about "brain wiring" and how kids learn to speak, think, and regulate their behavior. It examines the effect of the climate-family, child care, community-within which the child grows.

It has been recognized for more than a thousand years that the function of the brain, like the function of the other organs of the body, is determined by its physical, chemical, and biological properties. Evidence that even its highest functions could be explained by these properties was gathered only in recent years, however; these findings, which clearly have to be confirmed by a great deal of further experimental evidence, indicate that most, if not all, of the functions of the brain are based on its bio chemical and biophysical mechanisms. This at first hearing may sound rather simple, but the ability to understand learning, emotion, perhaps even creativity, on biological terms may well be the most important scientific discovery of all time. Few pieces of knowledge can influence our future health and well-being to the degree that understanding of mental mechanisms will. It has been clearly shown in many ways in the previous volumes of this Handbook that from the biochemical or neurochemical point of view the brain is one of the most active organs. The brain seems stable and in some respects permanent; this is evidence not of inactivity but of carefully controlled homeostasis, of dynamic rather than static equilibrium, with most components undergoing metabolic alterations.

Life, either as we think of it in the abstract in its highest sense, or life, as we think of it in terms of a compact living organism, is obviously the result of complex interaction of all of the components of the organism. One could therefore question the advisability of separating out the nervous system for a special detailed study in our age of overspecialization. The main purpose of the present Handbook is not to fragment further our approach or under standing of living phenomena, but, on the contrary, to try to summarize and integrate as much of the available information and thinking on the nervous system as is possible in a limited space. It is difficult to think of an area of modern biology that is more exciting to study and that has greater impor tance for mankind, from any point of view, than the study of the brain and of the nervous system. The influence that understanding of brain function in biological terms can exert on our future is not generally understood in its full impact. Although our ignorance about even the most basic mechanisms in the nervous system is enormous, in recent years our knowledge has made most important advances, and as a consequence great masses of data have been accumulated.