Based on a large variety of experiments on both humans and animals, this volume presents novel conceptualizations of the organizing consequences of hormones throughout the lifespans of mammals.

ELLIOTT M. BLASS Fifteen years have passed since the first volume on developmental psychobiology (Blass, 1986) appeared in this series and 13 since the publication of the second volume (Blass, 1988). These volumes documented the status of the broad domain of scientific inquiry called developmental psychobiology and were also written with an eye to the future. The future has been revolutionary in at least three ways. First, there was the demise of a descriptive ethology as we had known it, to be replaced first by sociobiology and later by its more sophisticated versions based on quantitative predictions of social interactions that reflected relatedness and inclu­ sive fitness. Second, there was the emergence of cognitive science, including cogni­ tive development, as an enormously strong and interactive multidisciplinary effort. Making the "functional" brain more accessible made this revolution all the more relevant to our discipline. In the laboratory, immunocytochemical detection of immediate / early genes, such as los, now allows us to trace neuronal circuits activated during complex behaviors. The "functional" brain of primates, especially humans, was also made very accessible through neuroimaging with which we can look at and into brains as they solve and attempt to solve particular tasks. Those of us who were trained in neurology as graduate students two or three decades ago recognize only the people in white coats and patients in beds or on gurneys when we visit neurologi­ cal units today. The rest is essentially new.

"The Handbook of Behavioral Neurobiology Series" deals with the aspects of neurosciences that have the most direct and immediate bearing on behavior. It presents the most current research available in the specific areas of sensory modalities. This volume explores circadian rhythms.

Volume 14 is an updated version of Volume 10 in the Handbook of Behavioral Neurobiology series. This time, Edward Stricker is joined by co-editor Stephen Woods, whose psychiatry affiliation balances Dr. Stricker's more physiological approach. Volume 14 provides the reader with a wide variety of perspectives on the enormous changes that have occurred in the study of food and fluid intake since the first edition of Neurobiology of Food and Fluid Intake published 14 years ago. As with the first edition, multiple viewpoints on issues of clinical significance and basic studies using laboratory animals are revealed, as world renowned experts in the field discuss homeostasis in various areas of alimentary behaviour and brain function. The text details the integration of the biological and behavioral contributions to homeostasis and the way in which basic neuroscientific studies of animal subjects can be used to illuminate parallel clinical phenomena in human subjects. Four retrospective essays on how the field has developed have been added to this new edition, and all chapters have been updated to integrate new material.New chapters in Volume 14 include motivation, food intake, body fluids, and an entirely new section on Reward, an important topic to cover in any study of motivated behaviour. Volume 14 of Handbook of Behavioral Neurobiology will be a valuable addition to the libraries of those interested in the study of neurosciences, nutrition, physiology, behavioral medicine, psychiatry, and neuroendocrinology.

When I began graduate school in 1961, Physiological Psychology was alive with adventure and opportunity. It seemed possible, indeed easy, to determine which part of the brain influenced which aspect of behavior, and the relative absence of technical hurdles encouraged neophytes into the laboratory. New theories of brain function based on a wealth of reliable and provocative findings also stimu­ lated further laboratory investigation. And the results obtained in studies of food and fluid ingestion certainly were exciting, albeit perplexing. For example, eating could be stimulated by injecting one chemical agent into the rat brain, whereas drinking was stimulated by i~ecting a different chemical through the same hypothalamic cannula. After focal brain lesions rats would overeat but not work harder to obtain food. After other brain lesions in adjacent sites, rats would stop eating and drinking altogether, but ingestive behaviors would return gradu­ ally over a period of weeks or months despite permanent brain injury. Although some of these observations and related findings may provide less insight into the central control of ingestive behavior than had been believed initially, there was a strong impression then that much more was known about eating and drinking than other behaviors, and they became models of motivated activities in addition to being of interest in their own right. Twenty-two years ago, the American Physiological Society published the first handbook devoted exclusively to the subject of alimentary behavior.

As the Handbook of Behavioral Neurobiology moves into a second volume, it is appropriate to take into general account the scope and content of this series. In its broadest sense, behavioral neurobiology is the study of the behaviors of animal organisms with reference to their neurological bases. The overall objective of this handbook series is to assemble, in ten volumes, a comprehensive and up-to-date treatment of the major areas that comprise behavioral neurobiology. Within such a framework, it is possible to provide the fundamental concepts, methods, and substantive advancements in these fields in a manner that will be useful to and that will also serve as a reference source for researchers educational programs who desire a well-balanced overview of the component areas of neurobiology. The intent in each volume has been to bring together a spectrum of approaches and disciplines that focuses upon the topic at hand. The first volume presented and discussed the problems of sensory integration; the present work is concerned with the neurobiology of cognitive processes; and forthcoming volumes will include the topics of motor coordination, learning and memory, biological rhythms, motivation, sexual behavior, social behavior and communication, and the evolution of nervous systems and behavior. Thus the purpose of the editors in planning this series has been to offer a distinct handbook, employing the many varied and prevailing avenues of attack upon current problems in behavior and neurological processes, that should prove of unique value and usefulness to professionals and students alike.

The Handbook of Behavioral Neurobiology series deals with the aspects of neurosciences that have the most direct and immediate bearing on behavior. It presents the most current research available in the specific areas of sensory modalities. This volume explores circadian rhythms.

ELLIOTT M. BLASS Fifteen years have passed since the first volume on developmental psychobiology (Blass, 1986) appeared in this series and 13 since the publication of the second volume (Blass, 1988). These volumes documented the status of the broad domain of scientific inquiry called developmental psychobiology and were also written with an eye to the future. The future has been revolutionary in at least three ways. First, there was the demise of a descriptive ethology as we had known it, to be replaced first by sociobiology and later by its more sophisticated versions based on quantitative predictions of social interactions that reflected relatedness and inclu­ sive fitness. Second, there was the emergence of cognitive science, including cogni­ tive development, as an enormously strong and interactive multidisciplinary effort. Making the "functional" brain more accessible made this revolution all the more relevant to our discipline. In the laboratory, immunocytochemical detection of immediate / early genes, such as los, now allows us to trace neuronal circuits activated during complex behaviors. The "functional" brain of primates, especially humans, was also made very accessible through neuroimaging with which we can look at and into brains as they solve and attempt to solve particular tasks. Those of us who were trained in neurology as graduate students two or three decades ago recognize only the people in white coats and patients in beds or on gurneys when we visit neurologi­ cal units today. The rest is essentially new.

The subject of this book is reproduction-specifically, the interplay between reproductive physiology (especially neural and endocrine events) and behavior. In presenting this topic, there are two expository goals. The first is to study repro- duction at all of the major levels of biological organization-from the molecular (e. g. , hormone receptors in the brain), through the cellular (e. g. , ovarian morphogene- sis), systemic (e. g. , operation of the hypothalamo-pituitary-ovarian axis), and the organismic levels of organization. Analogously, behavior is treated from the most molecular, elementary, and fundamental components (e. g. , copulatory reflexes), through behavior in the reproductive dyad (e. g. , analysis of female sexual behav- ior), to complex social behavior (e. g. , the interaction of social context and behav- ioral sex differences). To the extent that these levels of biological and behavioral organization rep- resent a "vertical axis" in behavioral neurobiology, a second goal is to treat the "horizontal axis" of biological organization, viz. , time. There are, therefore, treat- ments of evolutionary origins (e. g., a phylogenetic survey of psychosexual differ- entiation), genetic origins in the individual (e. g. , sexual organogenesis), ontoge- netic development (e. g. , behavioral sexual differentiation), and the immediate physiological precursors of behavior (e. g. , hormonal and nonhormonal initiation of maternal behavior). In addition to tracing the origins of reproduction and reproductive behavior, one extends the time-line from the behavior to its physio- logical consequences (e. g. , neuroendocrine consequences of sexual behavior).

The previous volume in this series (Blass, 1986) focused on the interface between developmental psychobiology and developmental neurobiology. The volume emphasized that an understanding of central nervous system development and function can be obtained only with reference to the behaviors that it manages, and it emphasized how those behaviors, in tum, shape central development. The present volume explores another natural interface of developmental psy­ chobiology; behavioral ecology. It documents the progress made by developmental psychobiologists since the mid-1970s in identifying capacities of learning and con­ ditioning in birds and mammals during the very moments following birth-indeed, during the antenatal period. These breakthroughs in a field that had previously lain dormant reflect the need to "meet the infant where it is" in order for behavior to emerge. Accordingly, studies have been conducted at nest temperature; infants have been rewarded by opportunities to huddle, suckle, or obtain milk, behaviors that are normally engaged in the nest. In addition, there was rejection of the exces­ sive deprivation, extreme handling, and traumatic manipulation studies of the 1950s and 1960s that yielded information on how animals could respond to trauma but did not reveal mechanisms of normal development. In their place has arisen a series of analyses of how naturally occurring stimuli and situations gain control over behavior and how specifiable experiences impose limitations on subsequent development. Constraints were identified on the range of interactions that remained available to developing animals as a result of particular events.

Like previous handbooks, the present volume is an authoritative and up-to-date compendium of information and perspective on the neurobiology of ingestive behaviors. It is intended to be stimulating and informative to the practitioner, whether neophyte or senior scholar. It is also intended to be accessible to others who do not investigate the biological bases of food and ?uid ingestion, who may teach aspects of this material or simply wonder about the current state of the ?eld. To all readers, we present this handbook as a progress report, recognizing that the present state of the ?eld is much farther along than it was the last time a handbook was published, but mindful of the likelihood that it is not as far along as it will be when the next handbook is prepared. This ?eld has witnessed a spectacular accretion of scienti?c information since the ?rst handbook was published in 1967. During the generation of science between then and the publication of the second handbook in 1990, numerous scienti?c reports have substantially changed the perspective and informational base of the ?eld.

Based on a large variety of experiments on both humans and animals, this volume presents novel conceptualizations of the organizing consequences of hormones throughout the lifespans of mammals.

ELLIOTT M. BLASS Fifteen years have passed since the first volume on developmental psychobiology (Blass, 1986) appeared in this series and 13 since the publication of the second volume (Blass, 1988). These volumes documented the status of the broad domain of scientific inquiry called developmental psychobiology and were also written with an eye to the future. The future has been revolutionary in at least three ways. First, there was the demise of a descriptive ethology as we had known it, to be replaced first by sociobiology and later by its more sophisticated versions based on quantitative predictions of social interactions that reflected relatedness and inclu­ sive fitness. Second, there was the emergence of cognitive science, including cogni­ tive development, as an enormously strong and interactive multidisciplinary effort. Making the "functional" brain more accessible made this revolution all the more relevant to our discipline. In the laboratory, immunocytochemical detection of immediate / early genes, such as los, now allows us to trace neuronal circuits activated during complex behaviors. The "functional" brain of primates, especially humans, was also made very accessible through neuroimaging with which we can look at and into brains as they solve and attempt to solve particular tasks. Those of us who were trained in neurology as graduate students two or three decades ago recognize only the people in white coats and patients in beds or on gurneys when we visit neurologi­ cal units today. The rest is essentially new.

"The Handbook of Behavioral Neurobiology Series" deals with the aspects of neurosciences that have the most direct and immediate bearing on behavior. It presents the most current research available in the specific areas of sensory modalities. This volume explores circadian rhythms.

Volume 14 is an updated version of Volume 10 in the Handbook of Behavioral Neurobiology series. This time, Edward Stricker is joined by co-editor Stephen Woods, whose psychiatry affiliation balances Dr. Stricker's more physiological approach. Volume 14 provides the reader with a wide variety of perspectives on the enormous changes that have occurred in the study of food and fluid intake since the first edition of Neurobiology of Food and Fluid Intake published 14 years ago. As with the first edition, multiple viewpoints on issues of clinical significance and basic studies using laboratory animals are revealed, as world renowned experts in the field discuss homeostasis in various areas of alimentary behaviour and brain function. The text details the integration of the biological and behavioral contributions to homeostasis and the way in which basic neuroscientific studies of animal subjects can be used to illuminate parallel clinical phenomena in human subjects. Four retrospective essays on how the field has developed have been added to this new edition, and all chapters have been updated to integrate new material.New chapters in Volume 14 include motivation, food intake, body fluids, and an entirely new section on Reward, an important topic to cover in any study of motivated behaviour. Volume 14 of Handbook of Behavioral Neurobiology will be a valuable addition to the libraries of those interested in the study of neurosciences, nutrition, physiology, behavioral medicine, psychiatry, and neuroendocrinology.

When I began graduate school in 1961, Physiological Psychology was alive with adventure and opportunity. It seemed possible, indeed easy, to determine which part of the brain influenced which aspect of behavior, and the relative absence of technical hurdles encouraged neophytes into the laboratory. New theories of brain function based on a wealth of reliable and provocative findings also stimu­ lated further laboratory investigation. And the results obtained in studies of food and fluid ingestion certainly were exciting, albeit perplexing. For example, eating could be stimulated by injecting one chemical agent into the rat brain, whereas drinking was stimulated by i~ecting a different chemical through the same hypothalamic cannula. After focal brain lesions rats would overeat but not work harder to obtain food. After other brain lesions in adjacent sites, rats would stop eating and drinking altogether, but ingestive behaviors would return gradu­ ally over a period of weeks or months despite permanent brain injury. Although some of these observations and related findings may provide less insight into the central control of ingestive behavior than had been believed initially, there was a strong impression then that much more was known about eating and drinking than other behaviors, and they became models of motivated activities in addition to being of interest in their own right. Twenty-two years ago, the American Physiological Society published the first handbook devoted exclusively to the subject of alimentary behavior.

As the Handbook of Behavioral Neurobiology moves into a second volume, it is appropriate to take into general account the scope and content of this series. In its broadest sense, behavioral neurobiology is the study of the behaviors of animal organisms with reference to their neurological bases. The overall objective of this handbook series is to assemble, in ten volumes, a comprehensive and up-to-date treatment of the major areas that comprise behavioral neurobiology. Within such a framework, it is possible to provide the fundamental concepts, methods, and substantive advancements in these fields in a manner that will be useful to and that will also serve as a reference source for researchers educational programs who desire a well-balanced overview of the component areas of neurobiology. The intent in each volume has been to bring together a spectrum of approaches and disciplines that focuses upon the topic at hand. The first volume presented and discussed the problems of sensory integration; the present work is concerned with the neurobiology of cognitive processes; and forthcoming volumes will include the topics of motor coordination, learning and memory, biological rhythms, motivation, sexual behavior, social behavior and communication, and the evolution of nervous systems and behavior. Thus the purpose of the editors in planning this series has been to offer a distinct handbook, employing the many varied and prevailing avenues of attack upon current problems in behavior and neurological processes, that should prove of unique value and usefulness to professionals and students alike.

The Handbook of Behavioral Neurobiology series deals with the aspects of neurosciences that have the most direct and immediate bearing on behavior. It presents the most current research available in the specific areas of sensory modalities. This volume explores circadian rhythms.

ELLIOTT M. BLASS Fifteen years have passed since the first volume on developmental psychobiology (Blass, 1986) appeared in this series and 13 since the publication of the second volume (Blass, 1988). These volumes documented the status of the broad domain of scientific inquiry called developmental psychobiology and were also written with an eye to the future. The future has been revolutionary in at least three ways. First, there was the demise of a descriptive ethology as we had known it, to be replaced first by sociobiology and later by its more sophisticated versions based on quantitative predictions of social interactions that reflected relatedness and inclu­ sive fitness. Second, there was the emergence of cognitive science, including cogni­ tive development, as an enormously strong and interactive multidisciplinary effort. Making the "functional" brain more accessible made this revolution all the more relevant to our discipline. In the laboratory, immunocytochemical detection of immediate / early genes, such as los, now allows us to trace neuronal circuits activated during complex behaviors. The "functional" brain of primates, especially humans, was also made very accessible through neuroimaging with which we can look at and into brains as they solve and attempt to solve particular tasks. Those of us who were trained in neurology as graduate students two or three decades ago recognize only the people in white coats and patients in beds or on gurneys when we visit neurologi­ cal units today. The rest is essentially new.

The subject of this book is reproduction-specifically, the interplay between reproductive physiology (especially neural and endocrine events) and behavior. In presenting this topic, there are two expository goals. The first is to study repro- duction at all of the major levels of biological organization-from the molecular (e. g. , hormone receptors in the brain), through the cellular (e. g. , ovarian morphogene- sis), systemic (e. g. , operation of the hypothalamo-pituitary-ovarian axis), and the organismic levels of organization. Analogously, behavior is treated from the most molecular, elementary, and fundamental components (e. g. , copulatory reflexes), through behavior in the reproductive dyad (e. g. , analysis of female sexual behav- ior), to complex social behavior (e. g. , the interaction of social context and behav- ioral sex differences). To the extent that these levels of biological and behavioral organization rep- resent a "vertical axis" in behavioral neurobiology, a second goal is to treat the "horizontal axis" of biological organization, viz. , time. There are, therefore, treat- ments of evolutionary origins (e. g., a phylogenetic survey of psychosexual differ- entiation), genetic origins in the individual (e. g. , sexual organogenesis), ontoge- netic development (e. g. , behavioral sexual differentiation), and the immediate physiological precursors of behavior (e. g. , hormonal and nonhormonal initiation of maternal behavior). In addition to tracing the origins of reproduction and reproductive behavior, one extends the time-line from the behavior to its physio- logical consequences (e. g. , neuroendocrine consequences of sexual behavior).

The previous volume in this series (Blass, 1986) focused on the interface between developmental psychobiology and developmental neurobiology. The volume emphasized that an understanding of central nervous system development and function can be obtained only with reference to the behaviors that it manages, and it emphasized how those behaviors, in tum, shape central development. The present volume explores another natural interface of developmental psy­ chobiology; behavioral ecology. It documents the progress made by developmental psychobiologists since the mid-1970s in identifying capacities of learning and con­ ditioning in birds and mammals during the very moments following birth-indeed, during the antenatal period. These breakthroughs in a field that had previously lain dormant reflect the need to "meet the infant where it is" in order for behavior to emerge. Accordingly, studies have been conducted at nest temperature; infants have been rewarded by opportunities to huddle, suckle, or obtain milk, behaviors that are normally engaged in the nest. In addition, there was rejection of the exces­ sive deprivation, extreme handling, and traumatic manipulation studies of the 1950s and 1960s that yielded information on how animals could respond to trauma but did not reveal mechanisms of normal development. In their place has arisen a series of analyses of how naturally occurring stimuli and situations gain control over behavior and how specifiable experiences impose limitations on subsequent development. Constraints were identified on the range of interactions that remained available to developing animals as a result of particular events.

Like previous handbooks, the present volume is an authoritative and up-to-date compendium of information and perspective on the neurobiology of ingestive behaviors. It is intended to be stimulating and informative to the practitioner, whether neophyte or senior scholar. It is also intended to be accessible to others who do not investigate the biological bases of food and ?uid ingestion, who may teach aspects of this material or simply wonder about the current state of the ?eld. To all readers, we present this handbook as a progress report, recognizing that the present state of the ?eld is much farther along than it was the last time a handbook was published, but mindful of the likelihood that it is not as far along as it will be when the next handbook is prepared. This ?eld has witnessed a spectacular accretion of scienti?c information since the ?rst handbook was published in 1967. During the generation of science between then and the publication of the second handbook in 1990, numerous scienti?c reports have substantially changed the perspective and informational base of the ?eld.