Research on thrombin structure and function has progressed significantly over the past three decades. We are continually discovering new functions f()r this enzyme in biology. Yet, until quite recently, a full, detailed, three dimensional picture of its structure was difficult to attain. We believe that this text represents a turning point and, more appropriately, a new start ing point for thrombin studies. Our goal for this text is to present a thorough and rounded-out coverage of thrombin chemistry and biochem istry in order to provide the biochemist and physiologist with an excellent desk reference on almost any thrombin-related problem. This volume is organized into three general thrombin topic areas: Structure, Biochemistry, and Physiology. In Part 1, Structure, we open with the complete three-dimensional x-ray structures of two inhibited human thrombin complexes, one of which is the thrombin-hirudin com plex. These complexes are also addressed in the chapter on structural studies in solution, which include NMR, ESR, and fluorescence. Part 2, Biochemistry, includes chapters on synthetic thrombin inhibitors, protein inhibitors (e.g., antithrombin III, hirudin), and thrombin interactions with factor XIII. Part 3, Physiology, covers such topics as chemotactic activities, interactions with cell surfaces, and the vascular endothelium.

This volume represents the proceedings of the 9th International Proton Transport Conference, "Mechanisms and Consequences of Proton Transport" held in Leura, Australia, August 19 -21, 200 I. This conference has been held since 1971 every 3 to 4 years with few exceptions in association with the Congress of the International Union of Physiological Sciences. The first meeting was held in Frankfurt, Germany, at the Max-Planck'Institute. Countries hosting the conference have been Germany (twice), Sweden (twice), India, Canada, USA, Great Britain, and now Australia. Over the past 30 years participants at these Proton Transport Conferences have been principal contributors to the major discoveries in the physiology, biochemistry and pharmacology of gastric acid secretion. These include development of the H2-receptor blockers, defining the signaling pathways for the regulation of acid secretion, identifying the gastric proton pump, discovery and development of proton pump inhibitory drugs, and elucidating the physiology and biochemistry of Helicobacter pylori.

In recent years rapid progress has been made in the areas of T cell and B cell biology, cell-cell and cell-matrix/stroma interactions. The use of isolated subunits of the T cell receptor invariant chains has been instrumental in defining their role in signal transduction and tyrosine phosphorylation. A role of src family phosphotyrosine kinases in T cell activation has been demonstrated and several phosphotyrosine kinase substrates have been identified and their functions characterized. Homologous recombinant techniques have led to the development of murine strains that lack CD4 or CD8 expression. These models are likely to be instrumental in studying the role of T cell subsets in autoimmune disorders, tissue transplant rejection and tumor rejection. A role of major histocompatibility complex I in the development of T cell subsets and NK cells has been defined. Recent data suggest a role of interaction between plasma membrane molecules of activated T helper cells and B cells, B cells primed with plasma membrane of activated T helper cells and cytokines, and interaction between bone marrow stromal cells and B cell progenitors and precursors, in the B cell development, proliferation, and differentiation. The structure and functions of adhesion molecules, especially with regard to signal transduction and homing events, are better defined.

The International Scientific Symposium on Fibrinogen, Thrombosis, Coagulation, and Fibrinolysis was held in Academia Sinica, Taipei, Taiwan, Republic of China, on August 30 - September 1, 1989. This Symposium has provided a forum for the free exchange of information in this important and rapidly advancing research field. This proceedings volume provides a published record of 46 papers presented at the Symposium. The sponsors have exerted no influence on the scientific opinions or positions of the participants in the Symposium. It is hoped that this Symposium will stimulate further worldwide cooperation and collaboration in these vital fields for the benefit of all human kind. This volume is composed of four parts. The first part consists of 8 papers on Fibrinogen and Fibrin: Biochemistry, Molecular Biology, and Physiology. The second part contains 16 papers on Coagulation and Fibrinolysis: Biochemistry, Molecular Biology, and Physiology. The third part has 10 papers on Cardiovascular Cell Biology: Biochemistry, Molecular Biology, and Physiology. The fourth part comprises 12 papers on Clinical Studies of the Cardiovascular System: Thrombotic and Bleeding Disorders and Thrombolytic Therapy. The Author Index with addresses of all contributors and the Subject Index of all 46 papers are arranged at the end of this volume.

Serpins (serine protease inhibitors) are a superfamily of proteins whose physiologi- cal action is primarily targeted to inhibiting serine proteases. There are instances where serpins are not inhibitors (and can carry steroid hormones for instance), yet key structural and functional elements found in all serpins are maintained in these 'non-inhibitor' ser- pins. Many serpins have well-described biological properties which influence pathophysi- ological events, including: antithrombin (historically called antithrombin III), ai-protease inhibitor (historically called ai-antitrypsin), and plasminogen activator inhibitor-I, just to mention a few. A deficiency or defect in antithrombin leads to venous thromboembolic disease, while a deficiency or defect in ai-protease inhibitor is associated with chronic obstructive pulmonary emphysema. In contrast, it has been suggested that increased levels of plasminogen activator inhibitor-l may be a predisposition to myocardial infarction. The list goes on for each of our own "favorite" serpin. The biological roles found for serpins are key participants in almost every physiological event. In other words, serine proteases are needed for many events in biology and the role of serpins to down regulate these pro- teases is essential. Thus, just using these three examples above for serpins and their patho- physiological roles reminds us that the medical costs to control such events is significant worldwide.

This monograph contains the proceedings from the Advanced Study Institute on "Vascular Endothelium: Physiological Basis of Clinical Problems" which took place in Corfu, Greece in June 1990. The meeting consisted of twenty-eight lectures, most of them adapted as full length papers in this volume, as well as numerous short oral and poster communications which are abstracted and also included in alphabetical order (pages 239-302). There were ninety-six participants from ten NATO and four other European countries. The meeting was the second in as many years dealing with a specific subject in Endothelial Cell biology. Following the 1988 discussion on "Receptors and Transduction Mechanisms", the present ASI recognized and tried to deal with the increasing overlap in interest between basic scientists studying endothelial cell functions and clinicians facing problems of known or suspected endothelial pathological involvement. As with any similar effort, we opted to be selective, rather than fail by trying to be inclusive, in the subjects covered. We chose to discuss diseases, such as atherosclerosis, sepsis, ARDS and stroke, based on their relevance to endothelial cell function and urgent need for new insights into their pathogenesis and treatment. Similarly, we examined endothelial cell functions by considering their relevance to disease and their potential for elucidating important pathologies. Obviously, some areas were covered superficially or not at all; this should not distract from their importance, but rather reflect on the constraints of time and -not at all negligibly -the bias of the organizing committee.

The Henry Goldberg Workshops were set up to address the following goals: (1) To foster interdisciplinary interaction between scientists and cardiologists, identify missing links, and catalyze new ideas. (2) To relate basic microscale phenomena to the global, clinically manifested cardiac function. (3) To relate conceptual modeling and quantitative analysis to experimental and clinical data. (4) To encourage international cooperation so as to disperse medical and technological knowhow and lead to better understanding of the cardiac system. The first Henry Goldberg Workshop, held in Haifa in 1984, introduced the concept of interaction between cardiac mechanics, electrical activation, perfusion, and metabolism, emphasizing imaging in the clinical environment. The second Workshop, in 1985, discussed the same parameters with a slant towards the control aspects. The third Goldberg Workshop, held in the USA at Rutgers University in 1986, highlighted the transformation of the microscale activation phenomena to macroscale activity and performance, relating electrophysiology, energy metabolism, and cardiac mechanics. The fourth Goldberg Workshop, in 1987, continued the effort to elucidate the interactions among the various parameters affecting cardiac performance, with emphasis on the ischemic heart. The fifth Workshop, held in Cambridge, UK, in 1988, dwelt on the effects of inhomogeneity of the cardiac muscle on its performance in health and disease. The sixth Workshop highlighted the role of new modem imaging techniques, that allow us to gain more insight into local and global cardiac performance in cardiac research and clinical practice.

Mesodenn is a key tissue in early development. It is involved in the differentiation of almost every organ in the body, not merely as a structural component, but as an active participant in the establishment of diverse cell types. All mesodenn is derived from ectoderm. Its appearance signals the start of a significant new phase in the development of the embryo. At this time all three genn layers are now present and myriad sequences of cell and tissue interactions begin to occur which will eventually give rise to the entire embryo. The control of the growth and differentiation of the mesoderm is critical for the production of a normal individual. Indeed, disturbance of the patterning of the mesoderm or of its interaction with other tissues plays a critical part in the fonnation of most congenital anomalies. The main focus of this book is therefore on the establishment, divergence and specialisation of mesodermal derivatives. The central role of the mesoderm in development has long been appreciated and a wide literature exists on its activity in certain specialised situations. Recently, however, an impetus to its study has been provided by new approaches opened up through biotechnological advances. Many of these advances are reflected in the reports in this volume. Scientists from various disciplines have become drawn to mesodermal tissues, and this volume may help them find a framework within which their work will fit.

During the past decade interest in the formation of complex disorderly patterns far from equilibrium has grown rapidly. This interest has been stim ulated by the development of new approaches (based primarily on fractal geometry) to the quantitative description of complex structures, increased understanding of non-linear phenomena and the introduction of a variety of models (such as the diffusion-limited aggregation model) that provide paradigms for non-equilibrium growth phenomena. Advances in computer technology have played a crucial role in both the experimental and theoret ical aspects of this enterprise. Substantial progress has been made towards the development of comprehensive understanding of non-equilibrium growth phenomena but most of our current understanding is based on simple com puter models. Pattern formation processes are important in almost all areas of science and technology, and, clearly, pattern growth pervades biology. Very often remarkably similar patterns are found in quite diverse systems. In some case (dielectric breakdown, electrodeposition, fluid-fluid displacement in porous media, dissolution patterns and random dendritic growth for example) the underlying causes of this similarity is quite well understood. In other cases (vascular trees, nerve cells and river networks for example) we do not yet know if a fundamental relationship exists between the mechanisms leading the formation of these structures.

This book deals with the cellular biology, biochemistry and physiology of photoreceptors and their interactions with the second-order neurons, bipolar and horizontal cells. The focus is upon the contributions made by these neurons to vision. Thus the basic neurobiology of the outer retina is related to the visual process, and visual defects that could arise from abnormalities in this part of the retina are highlighted in the first 16 chapters. Since all vertebrate retinas have the same basic structure and physiological plan, examples are given from a variety of species, with an emphasis upon mammals, extending to human vision. The last four chapters approach the problem from the other end. This part of the book covers a range of clinical conditions involving visual abnormalities that are due to cellular defects in the outer retina. Although the contents of this book do not represent the proceedings of a conference, the concept arose at an international symposium on 'Recent Advances in Retinal Research' which was held at the International Marine Centre in Oristano, Sardinia. We hope that the book will give a coherent, up to date review of the neurobiology and clinical aspects of the outer retina and encourage further integration of these areas. Retinal neurobiology has been an intense field of investigation for several decades. More recently, it has seen significant advances with the application of modern techniques of cell and molecular biology.

Proceedings of an international symposium, held in Ulm, Germany, September 21-24, 1994

The International Societyon Oxygen Transport to Tissue (ISOTT) was founded in 1973 "to facilitate the exchange of scientific information among those interested in any aspect of the transport and/or utilization of oxygen in tissues." Its members span virtually all disciplines, extending from various branches of clinical medicine such as anesthesiology, ophthalmology and surgery through the basic medical sciences of physiology and biochemistry to most branches ofthe physical sciences and engineering. The eighteenth annual meeting of ISOTT was held in 1990 for four days, from July 19 to 22, in the Sheraton Hotel in Townsville, Queensland, Australia. The usual ISOTT format, which was originated in 1985 by Dr. Ian Longmuir, was continued. Almost all presentations were posters with an accompanying, scheduled, brief, slide presentation and discussion. All posters remained in place for the entire four days of the meeting. There were no simultaneous sessions. Essentially all aspects of physiological transport were covered at this meeting with possibly somewhat more emphasis on methods and instrumentation. The editors gratefully acknowledge the photographic skills of Dr. Jens Hoper who took the group picture during the outing to Magnetic Island on July 21. We are also most grateful to Dr. Rod D. Braun of Evanston for his invaluable editorial assistance. This volume is the thirteenth in the Plenum series Oxygen Transport to Tissue.

From the 19-29 May 1991 the NATO ASI Course PAsthma Treatment: A P Multidisciplinary Approach was held in Erice, on the rocky North West Coast of Sicily, facing the ancient Phoenician shore of the African Continent. Sixty NATO sponsored participants arriving from many different European Countries - Nato members and non - attended the course. Qualified researchers from Europe and the United States held extensive lectures, short meetings and small informal group discussions. Erice is a magical place which draws together people from different backgrounds and cultures under her Mediterrean charm, recreating the ancient Greek openair discussion atmosphere. And so, during the 10 days gathering, the extensive willingness of the senior investigators and the laudable enthusiasm of the younger participants was stimulated. All of the most recent findings in the biology and the pharmacology of Asthma were discussed, initially behind closed doors, to be unhurriedly continued along the alley ways of the "Cittadella della Scienza" , in Erice's small restaurants, and on her deserted beaches. The texts collected here are testimony to the high quality of the investigators contributions as well as their far reaching interests. I think that a Director of such a Course would be adequatly satisfied by merely considering the enthusiasm and high level involvement of every participant. He could not have been more satisfied after having considered the proceedings summerizing the scientific content of the meeting.

Two techniques were used to estimate the L/M cone ratio, best-fit linear sum of the L- and M-cone spectral sensitivities to heterochromatic flicker photometric spectral sensitivity and psychometric function shape for point source detection of lights of varying wavelength. Data from five color-normal observers run on both paradigms all are consistent with a preponderance of L-cones relative to M-cones though there are individual differences in the estimates of L/M cone ratio. The observers showed congruence in their individual results across technique. In a separate study, the perceptual consequences of individual variation in L/M cone populations were evaluated by looking for a relation between flicker photometric spectral sensitivity and the spectral locus of equilibrium yellow. No significant relation was found, suggesting that receptor populations do not play a major role in the normalization of the perceptual red/green opponent channel. ACKNOWLEDGEMENT Supported in part by USPH NEI grant EY00901. REFERENCES Adam, A. (1969) Foveal red-green ra. C10S c:,f normals, colorblinds and heterozygotes. Proceedings Tel-Hasrcomer Hospital (Tel-Aviv). 8: 2-6. Ahnelt, P. , H. Kolb and R. Pflug. (1987). Identification of a subtype of cone photoreceptor, likely to be blue sensitive, in the human retina. Journal of Compa:cative Neurology. 255: 18-34. Alpern, M. and E. Pugh. (1977). variation in the action spectrum of erythrolabe among deuteranopes. Journal of Physiology (London). 266: 613-646. Boynton, R. (1979). Human Color Vision. New York, Holt, Rinehart and Winston. Brindley, G. (1954) The summation areas of human colour-receptive mechanisms at increment threshold.

The symposium on Acoustical Signal Processing in the Central Auditory System which was held in Prague on September 4--7, 1996 was the third in a series organized in Prague, after the Neuronal Mechanisms of Hearing symposium in 1980 and Auditory Pathway - Structure and Function symposium in 1987. Approximately 100 scientists regis tered for the symposium and presented 82 separate papers and posters. The present vol ume contains 53 of these contributions, mostly presented at the symposium as invited review papers. Several essential changes occurred since the previous meeting in 1987. In auditory neuroscience, recently developed methods opened new horizons in the investigation of the structure and function of the central auditory pathway. Methods like c-fos tracing tech niques and monoclonal antibodies for neurotransmitters and their receptors, like the intro duction of electrophysiological recording from brain slices have made possible new insights into the function of individual neurons and their interconnections, particularly in the cochlear nuclei and in the superior olivary complex. Integrative approaches towards understanding the central auditory function started to dominate in the field. It is not easy at the present time to differentiate between purely morphological and neurochemical ap proaches; similarly electrophysiological approaches are accompanied inevitably by behav ioral and psychophysical studies. The understanding of human brain function advanced significantly during the last several years. mainly due to the contribution of magneto encephalography. positron emission tomography and functional nuclear magnetic reso nance imaging.

Studies have identified important families of proteins (denoted: heat shock or stress proteins, Hsps) which display an enhanced expression in response to heat shock or other physiological stresses. Besides the characterization of the genes encoding Hsp and the mechanisms of their induction, recent studies have concentrated on the function of these proteins. It was shown that the expression of Hsp protects the cell against different types of aggressions. In addition,Hsp can regulate essential biochemical processes in unstressed cells. For example, members of the Hsp60 and Hsp70 families act as ATP-binding proteins allowing the folding of nascent or denatured proteins as well as the assembly or disassembly of protein complexes. These observations have led to the discovery of the molecular chaperone concept (Ellis and Hemmingsen 1989). Amongst the proteins whose expression is up-regulated by heat shock or other types of stresses are the small stress proteins also denoted (sHsps, sHsp or sHSP). Small stress proteins encompass a large numbers of related proteins which are represented in virtually all organisms, including prokary- otes. These polypeptides share a structural domain, often referred to as the a-crystallin domain, common to the lens protein alpha-crystallin (Ingolia and Craig 1982;Wistow 1985). In addition to being increased in response to several types of stresses, the Hsp level is also upregulated during development and correlates with the differentiation and oncogenic status of the cell. In spite of the fact that sHsp can confer cellular protection against stresses,their molecular function has remained enigmatic for years.

Birds and reptiles have long fascinated investigators studying hearing and the auditory system. The highly evolved auditory inner ear of birds and reptiles shares many characteristics with the ear of mammals. Thus, the two groups are essential in understanding the form and function of the vertebrate and mammalian auditory systems. Comparative Hearing: Birds and Reptiles covers the broad range of our knowledge of hearing and acoustic communication in both groups of vertebrates. This volume addresses the many similarities in their auditory systems, as well as the known significant differences about hearing in the two groups.

From recent developments in the rapidly growing area of neuroscience it has become increasingly clear that a simplistic description of brain function as a broad collection of simple input-output relations is quite inadequate. Introspection already tells us that our motor behavior is guided by a complex interplay between many inputs from the outside world and from our internal "milieu," internal models of ourselves and the outside world, memory content, directed attention, volition, and so forth. Also, our motor activity normally involves more than a circumscribed group of muscles, even if we intend to move only one effector organ. For example, a reaching movement or a reorientation of a sensory organ almost invariably requires a pattern of preparatory or assisting activities in other parts of the body, like the ones that maintain the body's equilibrium. The present volume is a summary of the papers presented at the symposium "Sensory Interaction in Posture and Movement Control" that was held at Smolenice Castle near Bratislava, Slovakia, as a Satellite Symposium to the ENA Meeting 1994 in Vienna. The focus of this meeting was not only restricted to the "classical" sensory interactions such as between vestibular and visual signals, or between otolith and semicircular canal inputs. Rather, the symposium tried to consider also the interplay between perception and action, between reflexive and volitional motor acts as well as between sensory driven or self-initi ated motor acts and reafferent inputs."

The cardiac system represents one of the most exciting challenges to human ingenuity. Critical to our survival, it consists of a tantalizing array of interacting phenomena, from ionic transport, membrane channels and receptors through cellular metabolism, energy production to fiber mechanics, microcirculation, electrical activation to the global, clinically observed, function, which is measured by pressure, volume, coronary flow, heart rate, shape changes and responds to imposed loads and pharmaceutical challenges. It is a complex interdisciplinary system requiring the joint efforts of the life sciences, the exact sciences, engineering and technology to understand and control the pathologies involved. The Henry Goldberg Workshops were set up to address these multivariable, multidisciplinary challenges. Briefly, our goals are: To encourage international cooperation and foster interdisciplinary interaction between scientists from the different areas of cardiology; to relate microscale cellular phenomena to the global, clinically manifested cardiac function; to relate conceptual modeling and quantitative analysis to experimental and clinical data; to gain an integrated view of the various interacting parameters, identify missing links, catalyze new questions, and lead to better understanding of the cardiac system. The outstanding success of past workshops has encouraged their continuation. The first Henry Goldberg Workshop, held in Haifa in 1984, introduced the concept of interaction between mechanics, electrical activation, perfusion and metabolism, emphasizing imaging in the clinical environment. The second Workshop, in 1985, discussed the same parameters with a slant towards the control aspects.

This volume contains the papers presented at the International Symposium on "Cirrhosis, Hyperammonemia and Hepatic Encephalopathy," held in Valencia, Spain, De- cember 2nd_4th, 1996. Liver cirrhosis is one of the main causes of death in occidental countries. There are other hepatic dysfunctions such as fulminant hepatic failure, Reye's syndrome, or congenital deficiencies of urea cycle enzymes which can also lead to hepatic encephalopathy, coma and death. However, the molecular bases ofthe pathogenesis of hepatic encephalopathy remain unclear. One ofthe consequences of hepatic failure is the reduced ability to detoxify ammonia by incorporating it into urea. This leads to increased blood ammonia levels. Hyperam- monemia is considered one of the main factors responsible for the mediation of hepatic encephalopathy and classical clinical treatments are directed towards reducing blood ammo- nia levels. Altered neurotransmission is an essential step in the pathogenesis of hepatic encephalopathy. The first part of the book is devoted to the discussion of the recent advances in the understanding of the alterations of different neurotransmitter systems in hepatic encephalopathy. The alterations of tryptophan metabolism and neurotransmission in hepatic encephalopathy and the implications for the clinical use of neuropsychoactive drugs are reviewed. The alterations in glutamate transport and neurotransmission in hepatic encephal- opathy due to acute liver failure are also reviewed. The role of NMDA receptors in the molecular mechanism of acute ammonia toxicity is discussed as well as its modulation by metabotropic glutamate receptors and muscarinic receptors.

In Volume 12, eminent international ornithologists further elucidate endocrinological correlates of mating strategies and hormones and reproductive behavior; assess the value of the ''brood reduction hypothesis'' in explaining ''the paradox of hatching asynchrony''; and explore the validity and sensitivity of growth bands in feathers as an indication of nutritional condition and the use of feather banding in studying growth. Chapters are well supported with charts, maps, schematic diagrams, and photographs. Current Ornithology is the only English-language publication currently devoted exclusively to extensive reviews and synthesis of topics pertaining to all aspects of the biology of birds. Chapters fall under such diverse rubrics as ecology, evolution, behavior, phylogeny, behavioral ecology, anatomy and physiology, and conservation biology. All authors are leading authorities on their subjects, and each chapter is refereed by experts in the topics covered. Although all chapters focus primarily on birds, some topics, such as the social cognition of birds as compared to primates (Volume 13), have significant application to disciplines outside of ornithology. Current Ornithology aims to provide an accessible, up-to-date, accurate source of data and to contribute to conceptual generalization and unification across the biological sciences.

A decade ago, for most scientists investigating various issues in life sciences the word "NO" was used in a negative context. It is astounding to observe how recently researchers are addressing the issue of NO, namely, nitric oxide, in over fifty publications weekly. Science journal, while naming nitric oxide: "Molecule of the Year" (December 1992), said it all: "NO news is good news. " For a long period of time NO was considered as a pollutant and every ecology minded person tried to eliminate it. It was the discovery of NO involvement in the process of host killing by macrophages and several years later the finding that EDRF is none else but NO, that promoted this field. Nitric oxide's major role in the control of blood pressure is merely one factor of an extensive list of effects and functions attributed to it. NO is implicated in long-term potentiation (LPT), a principal process involved in memory consolidation and it is considered as the main biochemical substance responsible for penile erection. It should be noted that additional roles for NO are discovered continuously as many laboratories join the quest for the mystery of this small molecule. The observation that NO is involved in various biological processes is not unique, as other second messengers (i. e., cyclic AMP), participate in a diverse set of functions."

Similarities in structure and function between pigs and human beings include size, feeding patterns, digestive physiology, dietary habits, kidney structure and function, pulmo nary vascular bed structure, coronary artery distribution, propensity to obesity, respiratory rates, tidal volumes and social behaviors. Since the pig is an omnivore, it provides an adaptable model to evaluate chronic and acute exposures to xenobiotics such as alcohoL caffeine, tobacco, food additives and environmental pollutants. Swine have been used successfully as models to evaluate alcoholism, diabetes, absorption, digestion, total paren teral nutrition, organ transplantation, atherosclerosis, exercise, hypertension. hemorrhagic hypotension, melanoma, gingivitis, obstructive and reflux nephropathy. osteochondrosis. dermal healing and septic shock. A severe and worsening shortage of organs and tissues for transplantation in patients with severe organ failure has encouraged the consideration of inter species or xenotransplan tation. In developing programs toward this end, the pig generally is viewed as the preferred donor because of its size, physiology and availability. The pig harbors relatively few diseases which could be transmitted inadvertently to human patients. The ability to genetically modify swine to ameliorate the consequences of the human immune response offers a further significant advantage. Another important consideration for an animal model is that basic biologic back ground information be available for investigators to design future prospective studies."

Understanding how the brain works is undoubtedly the greatest challenge for human intelligence and one of the most ambitious goals of contemporary science. We are certainly far from this goal, but significant advancements in several fields of Neuroscience and Neurobiology are being obtained at an increasing pace. The NATO ASI School in Neurobiology, held in Erice May 2-12,1995, as the 23rd Course of the International School of Biophysics, provided an update on three basic topics: Biophysics and Molecular Biology ofIon Channels, Sensory Transduction, and Higher Order Functions. Current knowledge on these subjects was covered by formal lectures and critical discussions between lecturers and participants. This book collects original contributions from those scientists who attended the School. Many students presented their results in poster sessions, steering lively informal discussions. A selection of these contributions is also included. A major portion of the program of the School was devoted to a general overview of current trends of thought and experimental approaches in neurobiology, emphasising the importance of understanding molecular aspects of the elementary events underlying sensory transduction and processing in the nervous system, without indulging however in a pure reductionistic view of such complex phenomena. Recent studies of molecular biology and the electrophysiology of heterologously expressed ionic channels, have shed new light on the molecular mechanisms underlying ionic permeation of excitable membranes and its regulation by physical and chemical parameters.

This book represents Part 2 of a venture started by distinguished neuroscientists to visualize and advertise the experimentally advantageous preparations of the crustacean nervous system. The advantage is a combination of ease of dissection of key structures and the possibility of repeatedly accessing identified individual cells to measure the detailed response of the system to the experimentally imposed stimulus program. Of course, the neurosciences have to focus their research on the nervous system of mammals and man in order to understand the principles of function and their regulation if malfunctions occur. This is in line with efforts to investigate nervous systems throughout the animal kingdom. The specific potential of the encountered systems for exploratory research into hitherto unexplained functions of the brain may very well be a key to new insights. The simply organized nervous system of crustaceans performs tasks of vital importance imposed on the organism. Hence this system consists of a complete set of neural circuitry open for inspection and measurement by systematic investigation. The first volume, The Crustacean Nervous System, contains exhaustive reports on experimental work from all sectors of neuroscience using crayfish and lobsters. This second volume, Crustacean Experimental Systems in Neurobiology," contains excellent reviews on significant topics in neurobiology. Each section is introduced by short texts written by the section editors of the Crustacean Nervous System. More, prominent authors explain their approach to understanding the brain using a selection of experiments involving visual orientation, neuromuscular systems and identification of principles of neural processing.