Primate locomotion has typically been studied from two points of view. Laboratory-based researchers have focused on aspects like biomechanics and energetics, whereas field-based researchers have focused on (locomotor) behaviour and ecology. Unfortunately, to date, there is relatively little scientific exchange between both groups. With a book, which will be the result of a symposium on the 2008 Meeting of the International Primatological Society in Edinburgh, we would like to bring together laboratory and field-based primate locomotion studies. We are convinced this will be beneficial for both research lines. For example, biomechanists might wonder how frequently the locomotor style they study in the lab actually occurs in nature, and field workers might use calculated costs of locomotion to understand why certain locomotor behaviours are favoured under specific conditions. Thus, on the one hand, an established link between both groups may help interpret the results by using each other's findings. On the other hand, recent technological advances (e.g. portable high-speed cameras) make it possible to bridge the gap between lab-based and field-based research by actually collecting biomechanical data in situ. Again, communication between both groups is necessary to identify the specific needs and start up achievable and successful research projects in the field. In order to generate a wide interest, we have invited biomechanists, ecologists, and field-based researchers who combine both disciplines, and we hope their combined contributions will facilitate lasting cooperation between the mentioned disciplines and stimulate innovative research in Primatology. We are convinced that the most appropriate format to publish the different symposium contributions is a conference volume within an existing book series. Firstly, the chapters will not only contain new data but will also review existing data and elaborate on potential future work - more so than can be done in a journal article. Secondly, the combination of chapters will form an entity that is more valuable than the sum of the separate chapters and therefore they need to be presented together. Lastly, this volume will benefit from the typically long "shelf life" of a book in a renowned series, allowing it to be used as reference book for both researchers and students.

This comprehensive treatise on the reticuloendothelial system is a project jointly shared by individual members of the Reticuloendothelial (RE) Society and bio medical scientists in general who are interested in the intricate system of cells and molecular moieties derived from those cells which constitute the RES. It may now be more fashionable in some quarters to consider these cells as part of what is called the mononuclear phagocytic system or the lymphoreticular system. Nevertheless, because of historical developments and current interest in the subject by investigators from many diverse areas, it seems advantageous to present in one comprehensive treatise current information and knowledge con cerning basic aspects of the RES, such as morphology, biochemistry, phylogeny and ontogeny, physiology, and pharmacology as weIl as clinical areas including immunopathology, cancer, infectious diseases, allergy, and hypersensitivity. It is anticipated that by presenting information concerning these apparently heterogeneous topics under the unifying umbrella of the RES attention will be focused on the similarities as weIl as interactions among the cell types constitut ing the RES from the viewpoint of various disciplines. The treatise editors and their editorial board, consisting predominantly of the editors of individual vol umes, are extremely grateful for the enthusiastic cooperation and enormous task undertaken by members of the biomedical community in general and especially by members of the American as weIl as European and Japanese Reticuloendothe lial Societies."

In 1961, neurobiologists found that the conduction velocity of the nerve impulse in the giant nerve fiber of the" Penaeus "shrimp abdominal nerve cord was over 200 m/s, the highest speed of information transmission ever observed in the animal kingdom. The peculiar myelin sheath with its unique nodal structure and the electrical properties of the nerve fibers of the shrimp have continued to be investigated for a quarter of century and are now fully described in this book. The investigation dispels the commonly held belief that the fastest recorded impulse conduction is about 120 m/s in the thickest vertebrate myelinated nerve fibers. In the shrimp, researchers found a completely novel type of functional node in the giant fiber which they designated as the fenestration node. In portions of the myelinated fiber, the fenestration node furnished the sites of excitation. Also discovered was a new strategy for increasing impulse conduction in the shrimp. The book includes a section on the formation of the fenestration node and the discovery of a strategy that allows the shrimp to escape its predators by an action of the fastest velocity. The data presented in this volume on the myelin sheath of invertebrates present a new direction for this field and a rich source of information for neurobiologists worldwide.

Anatomy, to be sure, is the essential foundation of clinical practice, but it is much more than that. First and foremost, anatomy is a biological science. There is order and logic to the organization of the human body and the arrangement of its parts. And, as all sciences, anatomy offers challenge and discovery. Concepts in Anatomy is not a textbook, but more of a brief handbook that is selective rather than encyclopedic in scope, conception rather than particular in its approach. It stresses general principles, so as to minimize rote learning, and it provides order and direction to the study of gross anatomy. Anatomy is inherently complicated and confusing; this volume helps you make sense of it in a way that also aims to inspire its study. Richly illustrated with original drawings, Concepts in Anatomy is a valuable resource for anyone currently studying or teaching the subject, or as a reference for advanced researchers.

`Are the Great Lakes getting better or worse?' This is the question that the public, scientists and managers are asking the International Joint Commission after a quarter-century of cooperative action by the United States and Canadian governments to clean up the Great Lakes. This volume contains papers from the workshop on Environmental Results, hosted in Windsor, Ontario, by the Great Lakes Science Advisory Board of the International Joint Commission, on September 12 and 13, 1996. The Great Lakes have been through almost a century of severe pollution from the manufacture, use and disposal of chemicals. In the 1960s wildlife biologists started to investigate the outbreaks of reproductive failure in fish-eating birds and ranch mink and to link these to exposure to organochlorine compounds. Human health researchers in the 1980s and 1990s linked growth retardation, behavioral anomalies and deficits in cognitive development with maternal consumption of Great Lakes fish prior to pregnancy. The Great Lakes became the laboratory where the theory of endocrine disruptors was first formulated. Now a group of Great Lakes scientists, hosted by the International Joint Commission, has compiled the story of the trends in the concentrations and effects of persistent toxic substances on wildlife and humans. The technical papers review the suitability of various organisms as indicators, and present the results of long-term monitoring of the concentrations and of the incidence of effects. The evidence shows that there was an enormous improvement in the late 1970s, but that in the late 1990s there are still concentrations of some persistent toxic substances that have stubbornly remained at levels that continue to cause toxicological effects.

(Chapters 11 to 14) summarise important features of the biological clock at the level of whole animal covering all vertebrate classes (fish to mammal). Chapters 15 and 16 are on long term (seasonal) rhythms in plants and higher vertebrates. Short term rhythms (ultradian rhythms), the significance of having a clock system in animals living in extreme (arctic) environments, and the diversity of circadian responses to melatonin, the key endocrine element involved in regulation of biological rhythms, have been discussed in Chapters 17 to 19. Finally, a chapter on sensitivity to light of the photoperiodic clock is added which, using vertebrate examples, illustrates the importance of wavelength and intensity of light on circadian and non-circadian functions. A well-known expert writes each chapter. When presenting information, the text provides consistent thematic coverage and feeling for the methods of investigation. Reference citation within the body of the text adequately reflects the literature as subject is developed. A chapter begins with an abstract that enables a reader to know at the first glance the important points covered in that chapter. The chapter concludes with a full citation of references included in the text, which could be useful for further reading. The book ends with a comprehensive subject index that may be useful for quick searches.

The German land of Hesse (Bundesland Hessen) is well known for its excellent wines (Rheinhessen), for its financial centre and for its airport (FrankfurtlMain). It is, unjustifiably, far less well known for its importance to thennoregulation. Within the small area of Bad Nauheim, Giessen and Marburg (in alphabetical order) a greater concentration of students of thenno regulation has been trained or worked or is working than probably in any other single area of Europe, if not the world. It is thus most appropriate to hold the Ninth International Symposium on the Pharmacology of Thennoregulation in Giessen, from August 7 to 12, 1994. The community of students of thennoregulation was extremely grateful that Professor Kurt Bruck and the lustus-Liebig-University of Giessen had extended this invitation. The same community was even more saddened that Kurt Bruck died on April 27, 1992 and thus could not participate in this event that had been planned to honour his achievements. As a small token of friendship and affection, the many friends of Kurt Bruck from all over the world who will participate in this event dedicate this symposium to the memory of Kurt Bruck. Another staunch friend, researcher of temperature regulation and supporter of this series of symposia died in October 1993: Professor Wilhelm Siegmund Feldberg. We feel fortunate to be able to start this volume with two brief infonnal and personal accounts of professors Bruck and Feldberg."

Regeneration, i.e. the replacement of lost body parts by new outgrowths or by remodelling existing tissues, has been studied for centuries. However, in recent years important developments took place in this field too, owing to new soph isticated techniques and to novel theoretical concepts. Advances in Molecular Genetics, Biochemistry, Cell and Neurobiology, Immunology, to mention a few of them, are the main causes of this resurgence of interest in regeneration. As a consequence, more and more meetings and pUblications are devoted, either exclusively or for a large part, to basic and applied research of regenerative processes. "Regeneration ists" scattered in laboratories allover the world and accus tomed to know each other through exchange of reprints - occa sionally an encounter in a large conference - tend now to form small groups, even societies and to institutionalize their meetings. Although the critical mass of scientists involved in regeneration research does not seem yet to be reached, for an autonomous development of this sector, regular and frequent meetings of experts appear useful, even necessary. Such a meeting was convened in Saronis, near Athens, Greece, from 19 to 23 September 1988 and sponsored by the NATO Science Committee and the University of Athens. The present volume contains the contributions to this Advanced Research Workshop on "Recent Trends in Regeneration Research". About 50 biologists from different countries, either mem bers of the Alliance or outside it (U.R.S.S., India, Egypt, Switzerland, Sweden) took part, mostly as invited speakers.

This book provides a comprehensive, up-to-date review of the distribution, pharmacology and physiology of central 5-hydroxytryptamine (5-HT)4 receptors. The 5-HT receptor subtypes exhibit a unique pharmacology, distribution and function, of which the 5-HT4 receptor has been one of the most intensively studied in recent years, both from a basic research standpoint and as a target for novel therapeutics.

In March 1996 the Society of Experimental Biology (UK) together with two other international scientific societies, the Australian and New Zealand Society for Comparative Physiology and Biochemistry and the Society for Integrative and Comparative Biology (formally the American Society for Zoology) joined forces with Springer-Verlag, Heidelberg to produce one of the first fully electronic online, peer-reviewed biological journals, Experimental Biology Online. The present product represents the fruits of this joint venture and encapsulates Volumes 1 and 2 of the journal. This will be an ongoing series such that an archival version of the journal will be available to all libraries as well as the on-line version. At the outset this was "new land" for all concerned but the launching of a journal which would cover experimental biology in terms of Animal, Cell and Plant topics was daunting but we all felt that the use of electronic media and the internet would be ideally suited to this purpose.

Intraspecific communication involves the activation of chemoreceptors and subsequent activation of different central areas that coordinate the responses of the entire organism-ranging from behavioral modification to modulation of hormones release. Animals emit intraspecific chemical signals, often referred to as pheromones, to advertise their presence to members of the same species and to regulate interactions aimed at establishing and regulating social and reproductive bonds. In the last two decades, scientists have developed a greater understanding of the neural processing of these chemical signals. Neurobiology of Chemical Communication explores the role of the chemical senses in mediating intraspecific communication. Providing an up-to-date outline of the most recent advances in the field, it presents data from laboratory and wild species, ranging from invertebrates to vertebrates, from insects to humans. The book examines the structure, anatomy, electrophysiology, and molecular biology of pheromones. It discusses how chemical signals work on different mammalian and non-mammalian species and includes chapters on insects, Drosophila, honey bees, amphibians, mice, tigers, and cattle. It also explores the controversial topic of human pheromones. An essential reference for students and researchers in the field of pheromones, this is also an ideal resource for those working on behavioral phenotyping of animal models and persons interested in the biology/ecology of wild and domestic species.

Twenty five years ago, Bill Stebbins presented the principles of animal psychophysics in an edited volume (Stebbins, 1970) describing an array of modem, creative methodologies for investigating the range of sensory systems in a variety of vertebrate species. These principles included precise stimulus control, a well defined behavioral response, and a rigorous behavioral procedure appropriate to the organism under study. As a generation of comparative sensory scientists applied these principles, our knowledge of sensory and perceptual function in a wide range of animal species has grown dramatically, especially in the field of hearing. Comparative psychoacoustics, i. e. , the study of the hearing capabilities in animals using behavioral methods, is an area of animal psychophysics that has seen remarkable advances in methodology over the past 25 years. Acoustic stimuli are now routinely generated using digital methods providing the researcher with unprecedented possibilities for stimulus control and experimental design. The strategies and paradigms for data collection and analysis are becoming more refined as well, again due in large part to the widespread use of computers. In this volume, the reader will find a modem array of strategies designed to measure detection and discrimination of both simple and complex acoustic stimuli as well experimental designs to assess how organisms perceive, identify and classify acoustic stimuli. Refinements in modem methodologies now make it possible to compare diverse species tested under similar, if not identical, experimental conditions.

The book "Parasitic Zoonoses" emphasizes a veterinary and public health perspective of zoonotic parasites. This book is suitable for higher undergraduate and graduate students of zoonoses and public health, veterinary parasitology, parasite epidemiology; public health workers; public health veterinarians; field veterinarians, medical professionals and all others interested in the subject. More than 15 protozoa and 50 other parasitic diseases are zoonotic in nature and all these diseases have been discussed in detail. The first chapter is concerned with classification of zoonotic parasites, food borne, vector borne and occupation related zoonotic parasites. The remaining chapters cover etiology, epidemiology, life cycle, transmission, clinical signs, diagnosis, prevention and control of zoonotic parasites. The text is illustrated with a large number of coloured figures. An alphabetical bibliography for every disease has also been included so that readers have access to further information.

Throughout history, hearing and sound perception have been typically framed in the context of how sound conveys information and how that information influences the listener. "Hear Where We Are" inverts this premise and examines how humans and other hearing animals use sound to establish acoustical relationships with their surroundings. This simple inversion reveals a panoply of possibilities by which we can re-evaluate how hearing animals use, produce, and perceive sound. Nuance in vocalizations become signals of enticement or boundary setting; silence becomes a field ripe in auditory possibilities; predator/prey relationships are infused with acoustic deception, and sounds that have been considered territorial cues become the fabric of cooperative acoustical communities. This inversion also expands the context of sound perception into a larger perspective that centers on biological adaptation within acoustic habitats. Here, the rapid synchronized flight patterns of flocking birds and the tight maneuvering of schooling fish becomes an acoustic engagement. Likewise, when stridulating crickets synchronize their summer evening chirrups, it has more to do with the 'cricket community' monitoring their collective boundaries rather than individual crickets establishing 'personal' territory or breeding fitness. In "Hear Where We Are" the author continuously challenges many of the bio-acoustic orthodoxies, reframing the entire inquiry into sound perception and communication. By moving beyond our common assumptions, many of the mysteries of acoustical behavior become revealed, exposing a fresh and fertile panorama of acoustical experience and adaptation.

Current Ornithology publishes authoritative, up-to-date, scholarly reviews of topics selected from the full range of current research in avian biology. Topics cover the spectrum from the molecular level of organization to population biology and community ecology. The series seeks especially to review (1) fields in which an abundant recent literature will benefit from synthesis and organization, or (2) newly emerging fields that are gaining recognition as the result of recent discoveries or shifts in perspective, or (3) fields in which students of vertebrates may benefit from comparisons of birds with other classes. All chapters are invited, and authors are chosen for their leadership in the subjects under review.

During the period August 5-9, 1992, and immediately preceding the 1992 Gordon Research Conference on Motile and Contractile Systems, the "Third International Conference on the Structure and Function of Ubiquitous Cellular Protein Actin" was held at the Emma Willard School in Troy, New York, under the title "ACTIN '92". This conference focused on the fundamental properties and cellular functions of actin and actin based microfilament systems. The first conference in this series was held in 1982, in Sydney, Australia, and hosted by Dr. Cristobal G. dos Remedios and Dr. Julian A. Barden, both from the University of Sydney (New South Wales, Austrailia). The second conference convened in Monza, Italy in June 1987, and was organized by Dr. Roberto Colombo, University of Milan (Italy). This third gathering of researchers devoted to the study of actin and actin-associated proteins was organized by Dr. James E. Estes, Albany Stratton V A Medical Center and Dr. Paul 1. Higgins, Albany Medical College, who were assisted by an Organizing Committee consisting of Dr. Edward D. Korn (National Heart, Lung and Blood Institute, NIH), Dr. Thomas P. Stossel (Massachusetts General Hospital), Dr. Fumio Matsumura (Rutgers University), and Dr. Stephen Farmer (Boston University). This meeting was dedicated to the many pioneering contributions of Professor Fumio Oosawa to the field of actin research.

by G. MILAZZO and M. BLANK This book contains the lectures of the fourth advanced course Bioelectrochemislry W Neroe-Muscle Function: Bioelectrochemistry, Mechanisms, Energetics and Contro~ which took place at the Majorana Center in Erice, Italy, October 20th to November 1, 1991. The scope of the course was international in terms of both sponsorship and partici pation. Sponsors included the Bioelectrochemical Society, NATO, International Union of Pure and Applied Biophysics (lUPAB), the World Federation of Scientists and the Italian National Research Council. One-third of the sixty participants were from Italy, but the majority came from eighteen other nations. Since the course was part of the International School of Biophysics, the biophysi cal point of view was emphasized in integrating the biology with the electrochemistry. Lecturers were asked to use a quantitative approach with accepted standards and proper units, since this is absolutely essential for developing an effective common language for communication across disciplines. Participants were also urged not to forget that biological systems could also be considered as physical systems. Ion channels are proteins and their properties as polyelectrolytes contribute to the specific biological properties. The existence of families of channels, with very similar structures but different selectivities, suggests that the specificities arise from slight variations of a general basic design. These perspectives on nerve-muscle function helped to make the school course a unique treatment of the subject.

Muscle contraction has been the focus of scientific investigation for more than two centuries, and major discoveries have changed the field over the years. Early in the twentieth century, Fenn (1924, 1923) showed that the total energy liberated during a contraction (heat + work) was increased when the muscle was allowed to shorten and perform work. The result implied that chemical reactions during contractions were load-dependent. The observation underlying the "Fenn effect" was taken to a greater extent when Hill (1938) published a pivotal study showing in details the relation between heat production and the amount of muscle shortening, providing investigators with the force-velocity relation for skeletal muscles. Subsequently, two papers paved the way for the current paradigm in the field of muscle contraction. Huxley and Niedergerke (1954), and Huxley and Hanson (1954) showed that the width of the A-bands did not change during muscle stretch or activation. Contraction, previously believed to be caused by shortening of muscle filaments, was associated with sliding of the thick and thin filaments. These studies were followed by the classic paper by Huxley (1957), in which he conceptualized for the first time the cross-bridge theory; filament sliding was driven by the cyclical interactions of myosin heads (cross-bridges) with actin. The original cross-bridge theory has been revised over the years but the basic features have remained mostly intact. It now influences studies performed with molecular motors responsible for tasks as diverse as muscle contraction, cell division and vesicle transport.

Volumes I and 2 of this Plant Biotechnology series reviewed fundamental aspects of plant molecular biology and discussed production and analysis of the first generation of transgenic plants of potential use in agriculture and horticulture. These included plants resistant to insects, viruses and herbicides, which were produced by adding genes from other organisms. Realisation of the potential of plant breeding has led to a resurgence of interest in methods of altering the structure, composition and function of plant constituents, which represents an even greater challenge and offers scope for improving the quality of a wide range of agricultural products. This, in tum, has resulted in a re-evaluation of priorities and targets by industry. Volume 3 of this series considers the biochemical and gentic basis of the biosynthesis of plant products such as starch, lipids, carotenoids and cell walls, and evaluates the ways in which biosynthesis of these products can be modified for use in the food industries. Authors also cover the biosynthesis of rare secondary products and the function and application of proteins for plant protection and therapeutic use. The emphasis throughout is on the relationship between fundamen tal aspects of biosynthesis and structure-function relationships, and application of this knowledge to the redesigning and altering of plant products by molecular genetics."

Fish comprise more than 50% of all living vertebrates and are found in a wide range of highly diverse habitats like the deep sea, the shoreline, tide pools, tropical streams and sweetwater ponds. During evolution, the senses of fish have adapted to the physical conditions of the environment in which different species live. As a result, the senses of fish exhibit a remarkable diversity that allows different species to deal with the physical constraints imposed by their habitat. In addition, fish have evolved several new' sensory systems that are unique to the aquatic environment.
In this book, examples of adaptation and refinement are given for six sensory systems: The visual system, The auditory system, The olfactory system, The mechanosensory lateral line system, The taste system, The electrosensory system. In each case, the environmental conditions under which a particular group of fish lives are analyzed. This is followed by a description of morphology and physiology of the sensory system and by an evaluation of its perceptional capabilities. Finally, the sensory adaptations to the particular conditions that prevail in the habitat of a species are highlighted.
The various examples from different groups of fish presented in this book demonstrate the impressive capability of fish sensory systems to effectively overcome physical problems imposed by the environment.

The basal forebrain has received considerable attention in recent years. This emphasis resulted from observations that the cortically projecting cholinergic neurons found in this region are critical for normal information processing. However, to achieve a complete understanding of such a complex function as "information processing" it is necessary to consider the basal forebrain not as an autonomous structure with a solitary task, but one that plays an integrative role; a structure that is connected intimately with many brain regions. This view evolved from the realization that the basal forebrain interfaces cognitive and reward functions with motor outputs. It is from this integrative and functional perspective that the present book was organized. The book is a unique collection of reports pertaining to the basal forebrain that encompasses a diversity of research approaches and techniques. It provides the reader with a progression of information that begins with anatomical descriptions of the afferent and efferent systems, stressing the integrative nature of various neurotransmitters located within the basal forebrain. The chapters focusing on anatomy are complemented by electrophysiologic studies that merge anatomical concepts with synaptic pharmacology and behavior. In vitro experiments demonstrate physiologic variations in anatomically identified neuronal subtypes and, together with in vivo techniques, provide pharmacologic descriptions of neuronal consequences to various neurotransmitter influences. Additional in vivo reports correlate changes in neuronal activity with specific motivational states and motor behaviors. These functional approaches culminate with behavioral studies that overview current understanding of basal forebrain involvement in mnemonic, reward, and motor processes.

A wealth of information has been accumulated about the function of ion channels of excitable cells since the extensive and pioneering voltage clamp studies by Hodgkin, Huxley, and Katz 36 years ago. The study of ion chan nels has now reached a stage at which a quantum jump in progress is antici pated. There are many good reasons for this. Patch clamp techniques origi nally developed by Neher and Sakmann 12 years ago have made it possible to study the function of ion channels in a variety of cells. Membrane ionic currents can now be recorded practically from many types of cells using the whole-cell patch clamp technique. The opening and closing of individual ion channels can be analyzed using the single-channel patch clamp method. Techniques have also been developed to incorporate purified ion channels into lipid bilayers to reconstitute an "excitable membrane. " Advanced tech niques developed in molecular biology, genetics, and immunology, such as gene cloning and the use of monoclonal antibodies, are now being applied to the study of ion channels. A variety of drugs have now been found or are suspected to interact with ion channels to exert therapeutic effects. In addition to the classical exam ples, as represented by local anesthetics, many other drugs, including cal cium antagonists, psychoactive drugs, cardiac drugs, and anticonvulsants, shown to alter ion channel function. For certain pesticides such as have been pyrethroids and DDT, sodium channels are clearly the major target site.

The concept for Vasopressin: Principles and Properties originated during the sum mer of 1983. From reviewing the rich and diverse literature on vasopressin, it became evident that the rapid advancements in this field made it difficult to syn thesize the information gathered from divergent scientific disciplines into a coherent view of the biological role of vasopressin. We perceived the need for a series of critical reviews delineating this recent progress. Over the past decade, major advances have been made in studies of the anatomy, physiology, phar macology, molecular biology, and behavioral activities of vasopressin. This is, in no small measure, due to the finding that vasopressin can no longer be regarded solely as a neurohypophysial hormone. Our present knowledge is that vasopressin is synthesized in also has an axonal messenger role in the nervous system and of the brain, although the functions of vasopressin in these periph sites outside of vasopressin eral sites are not well understood. In order to prepare an overview concentrating on recent studies in vertebrates, authors were selected based on their expertise and asked to review their research area, including the work from other laboratories. It was our intent to provide an updated definitive reference which would complement and extend such past texts as Neurohypophysial Hor mones and Similar Polypeptides (Handbook of Experimental Pharmacology, Vol ume XXIII, 1968) and The Pituitary Gland and Its Neuroendocrine Control (Handbook of Physiology, Section 7: Volume IV, 1974)."

One of the most impressive advances in the field of neuroscience over the last decade has been the accumulation of data on plasticity and regeneration in the nervous system of mammals. The book represents the contribution of a qroup of neuroscientists to this rapidly expanding field, through a Conference organized by the Institute of Developmental Neuroscience and Aging (IDNA). The meeting was held in Torino, Italy during April 1990 in honor of a great pioneer in the field of Neuroembryology, Professor Guido Filogamo. His introduction of the concept of neuroplasticity has had a significant impact on the study of neurobiology. This volume is divided into six sections, each focusing on one of the subject areas covered during the meeting Molecular and Cellular Aspects of Central and Peripheral Nervous System Development; Hormones,* Growth Factors, Heurotransmi tters, Xenobiotics and Development; In Vivo and in Vitro models of Development; Development and Regulation of Glia; Regeneration; and Aging.

From within complex structures of organisms and cells down to the molecular level, biological processes all involve movement. Muscular fibers slide on each other to activate the muscle, as polymerases do along nucleic acids for replicating and transcribing the genetic material. Cells move and organize themselves into organs by recognizing each other through macromolecular surface-specific interactions. These recognition processes involve the mu tual adaptation of structures that rely on their flexibility. All sorts of conformational changes occur in proteins involved in through-membrane signal transmission, showing another aspect of the flexibility of these macromolecules. The movement and flexibility are inscribed in the polymeric nature of essential biological macromolecules such as proteins and nucleic acids. For instance, the well-defined structures formed by the long protein chain are held together by weak noncovalent interac tions that design a complex potential well in which the protein floats, permanently fluctuating between several micro- or macroconformations in a wide range of frequencies and ampli tudes. The inherent mobility of biomolecular edifices may be crucial to the adaptation of their structures to particular functions. Progress in methods for investigating macromolecular structures and dynamics make this hypothesis not only attractive but more and more testable.