Journal Of Anatomy Research Articles

Symposium: ‘A celebration of neuroanatomy in the centennial of Cajal's Nobel Prize’

By 1889, at the age of 37 years, Cajal had published two papers on neuroanatomy in the Revista trimestral de Histologia normal y patologica, which he had founded (and subsidised) the previous year. However, his ideas received hardly any attention from his colleagues and he became a ‘little alarmed by their silence’ (Ramon y Cajal, 1981). He admitted that most histologists had not read his papers since ‘it is true that Spanish is an unknown language to the educated’ and he thought that the ‘direct objective demonstration’ of facts would be more convincing. Therefore, he first translated his principal papers into French and then decided to show his histological preparations to scientific colleagues, in order to demonstrate his findings and ideas. To this end, Cajal applied for membership of the Anatomische Gesellschaft, asked his Rector for permission to travel, collected all of his savings and set out for Berlin, where the Anatomische Gesellschaft met in October 1889.

Human White Matter Atlas

Human White Matter Atlas

The Sinoatrial Node Is Still Setting the Pace 100 Years After its Discovery

See related article, pages 1605–1614 The mammalian sinoatrial node, the pacemaker of the heart, was discovered 100 years ago in the countryside of Kent (UK) in “a cosy, squat, red-roofed farm-house, embowered in creepers, separated from the road by a richly stocked garden” with “a horse going round and round winding up a huge bucket from a very deep well” and a “farmyard, filled with healthy farmyard manure”.1 Arthur Keith (later Sir Arthur) had converted the drawing room into a laboratory and recruited the assistance of Martin Flack, the son of the local butcher and grocer and a young medical student at the time.1 One evening when Keith and his wife, Celia, returned from a bicycle ride, Flack showed him a “wonderful structure” he had discovered in the heart of a mole (perhaps caught on the farm?)—so was discovered the sinoatrial node. Keith and Flack published the discovery of the sinoatrial node in 1907 in the Journal of Anatomy and Physiology .2 Curiously, only a few years later, Keith was to become embroiled in one of the biggest scientific scandals of all time, ‘Piltdown man’, a fraudulent ‘missing link’. Now 100 years after the discovery of the sinoatrial node, we are still making new discoveries about the workings of the sinoatrial node as shown by the paper from Ju and Allen and colleagues in this issue of Circulation Research —the sinoatrial node is still setting the pace!3 In the 1970s and 1980s a flurry of voltage clamp studies, first on multicellular preparations of sinoatrial node tissue and then on isolated sinoatrial node cells, appeared to establish the mechanism of pacemaking in the sinoatrial node.4 At this time, pacemaking was primarily thought to be result of the decay of delayed rectifier K+ current (K …

From the 19th to the 21st century: Journal of Anatomy online

From the 19th to the 21st century: <i>Journal of Anatomy</i> online

Symposium on ‘The Anatomy of Exercise’

Symposium on ‘The Anatomy of Exercise’

Editorial

Bone, connective tissue and related subjects are not only one of the major strengths of the Journal of Anatomy, but an area of increasing research interest in the wider biomedical community. This issue of the journal is therefore particularly timely in bringing together a group of research articles in this area, ranging from structural characterization of adult bone mesenchymal stem cells (a potential therapeutic alternative to embryo-derived stem cells), to the periodic nature of secretion of the hardest substance in the body, dental enamel. The importance of musculoskeletal and connective tissues in locomotion is represented by studies on pelvic asymmetry, functional adaptations of the shoulder girdle related to walking vs. swimming, and specializations of the knee joint for load-bearing movement (especially its vulnerability to overuse in sport). As even the massive load of the elephant's body is transmitted through typical mammalian knees, perhaps it is not surprising to discover that these structures are particularly prone to arthrosis. Another interesting observation related to long-term load-bearing is that two types of microcrystal are deposited in degenerating human intervertebral discs. Load-bearing is also important during bone development and growth, through biomechanical forces that affect whether bone is organized into, and maintained as, trabecular or cortical bone. Later, within the beautiful microstructure of mature bone, there are discontinuities of pattern that may act as stress concentration sites in which tiny cracks are initiated, but happily other discontinuities (the cement lines surrounding osteons) act as barriers limiting crack propagation. Movement at joints commonly involves bursae to lubricate and protect the moving parts; during plantarflexion and dorsiflexion of the foot, a deformable fat pad attached to the Achilles tendon and other structures is an additional component of the movement-facilitating mechanism. Magnetic resonance imaging of movement-related structures enables both soft and hard tissues to be visualized, but new imaging techniques are constantly being developed and assessed. Multiple image radiology produces an additional image that conveys microstructure (ultra-small-angle X-ray scattering). Similar views of the hindfoot/heel region in these two adjacent papers enable the reader to assess the relative merits of the different techniques. I thank all the authors of the papers in this issue and hope that the readership enjoys them. I would be interested to hear whether people like the idea of grouping related papers in a single issue and am always open to any other suggestions for ways in which Journal of Anatomy could better serve its readers. Since this editorial was written, the order of two papers has changed: the first of the two articles on dental enamel by Smith and colleagues has been inserted between the two imaging articles, referred to above as adjacent (Theobald et al. and Muehleman et al.).

Craniofacial development: making faces

Craniofacial development has traditionally been a field of research in which many divergent views are expressed and novel theories put forward to explain observed normal and abnormal phenomena. Decades of investigation have shown that craniofacial development is an intricate and complex series of events that require inductive and directive cell and molecular interactions to control the initiation, movement and differentiation of various embryonic cell populations across a spatial and temporal time continuum that results in the correct outgrowth, patterning and tissue integration required to make a face. This special issue of the Journal of Anatomy contains review articles written by speakers from the ‘Craniofacial Development: Making Faces’ symposium held as part of the Winter Meeting of the Anatomical Society at Oxford in January 2005. The volume covers wide-ranging aspects of craniofacial development from the evolution of the head, tissue patterning and morphogenesis to human syndromes and malformations. The thoughtful and insightful reviews illustrate many foci of current research in this area and highlight the challenges that lie ahead in fully understanding the mechanisms underlying the processes required to generate the vertebrate head.

Symposium on ‘Neural stem and progenitor cells: biology and clinical potential’, part one

In July 2004 the Department of Anatomy at University College Cork, Ireland, hosted the summer meeting of the Anatomical Society of Great Britain and Ireland in conjunction with a meeting of the Irish National Neuroscience Network. In addition to the normal ASGBI summer meeting proceedings, a special international symposium entitled ‘Neural stem and progenitor cells: biology and clinical potential’ was held. The meeting also included update talks and posters from members of the National Neuroscience Network (NNN), an ongoing nationwide interdisciplinary research programme funded by the Irish Government's National Development Plan. The meeting and symposium were organized by Professor John Fraher, Dr Aideen Sullivan, Dr Kieran McDermott and Professor Arthur Butt. The symposium brought together international researchers who have contributed to recent developments in neural stem cell biology. Throughout the two days of the symposium, the invited experts, from a diverse range of backgrounds from basic biology to clinical applications, addressed outstanding issues relating to neural stem and progenitor cell characterization and nomenclature in development and in adulthood, as well as novel approaches to cell replacement therapies for neurological disorders. Review articles resulting from this symposium comprise this special issue of the Journal of Anatomy, and part of one issue that will follow later in the year. The symposium articles presented in this issue focus on the characterization and potential clinical application of neural stem and progenitor cells, as well as papers presented by members of the NNN. The October issue will contain review articles from the symposium that addressed the related issue of defining NG2-expressing cells in the CNS and their roles in regeneration and remyelination. The first six papers presented in this issue relate to neural stem cell biology and the potential of stem cells to be used in therapeutic approaches to neurological disorders. The article by Watts et al. discusses the biology of neural stem cells in the adult brain, their relevance to brain injury and disease, and their potential to be used for the development of novel treatments for neurological diseases. The papers by Maxwell & Li and Sullivan & O’Keeffe focus on midbrain dopaminergic neurons, which are of much interest in the development of new therapies for Parkinson's disease. Maxwell & Li have identified a number of regulatory factors, including Pitx3, that influence the development of these neurons in vivo. They also describe the generation of dopaminergic neurons in vitro from embryonic stem cells, which may have the potential to be used in transplantation approaches to Parkinson's disease. Sullivan & O’Keeffe describe a neurotrophic protein, GDF5, which has actions on the induction, survival and differentiation of midbrain dopaminergic neurons. These properties could be used to induce neuroprotection and/or to enhance transplantation in Parkinson's disease. Zietlow et al. describe some of their recent work involving the transplantation of embryonic neural precursor cells into the adult rat striatum. Their finding that the long-term expansion of these cells in vitro impairs their ability to survive long term after transplantation has implications for the potential use of these cells for neural transplantation strategies. The paper by McDermott et al. is concerned with radial glial cells – their roles as neuronal progenitor cells, as well as their involvement in cell migration and axonal growth in the developing brain and spinal cord. Zhao et al. discuss the biology of cells that respond to demyelinating disorders of the central nervous system, such as multiple sclerosis. They describe the types of adult stem and/or progenitor cells that may be activated following demyelination and may contribute to remyelination and repair. The four papers presented by invited members of the NNN demonstrate a few of the research themes under investigation by the neuroscience research community in Ireland. Dinan & Scott describe the involvement of the hypothalamic–pituitary–adrenal axis in melancholic depression. In particular, the roles of the hypothalamic hormones, corticotrophin-releasing hormone and vasopressin, are discussed. The paper by Moynagh reviews the contribution of interleukin-1 signalling in astrocytes in neuropathological conditions such as multiple sclerosis and Alzheimer's disease, and the potential of this signalling pathway to be exploited as a therapeutic target in the treatment of many neurological diseases. O'Mara's paper is concerned with synaptic plasticity in the subiculum, as well as the roles of this brain area in spatial navigation, mnemonic processing and the control of responses to stress. Finally, the article by Hennessy et al. demonstrates how facial dysmorphogenesis can be measured using three-dimensional laser scanning and geometric morphometrics. These measurements can serve as an accessible and informative index of brain dysmorphogenesis in neurological and psychiatric disorders of early developmental origin.

EDITORIAL INTRODUCTION: Functional anatomy of the brain

EDITORIAL INTRODUCTION: Functional anatomy of the brain

The A.J. Ladman AAA/Wiley Exemplary Service Award

The A.J. Ladman AAA/Wiley Exemplary Service Award

Correspondence

In the August 2004 issue of Journal of Anatomy, Kong and colleagues reported that unilateral vasectomy in rabbits resulted in ipsilateral (‘vasectomy-induced’) damage to spermatogenesis – most severely at 10 days (in all testes), and less severe in about half the testes at 6 and 12 months. This testis-damaging effect of vasectomy contrasts with their previous results in the rhesus monkey in which the testes showed no such damage. Because of an interest in the keratinoid tough quality of mammalian sperm, and how they are disposed of after vasectomy (and because of the importance of vasectomy in humans), in the mid-1970s I studied this question in the rhesus monkey, hamster, rat and rabbit (Bedford, 1976). After vasectomy in these animals spermatogenesis usually continued normally. However, sperm accumulation brought a rupture at one or more focal points in the lower epididymis or vas deferens within a few weeks in the monkey, hamster and rat – but with the rabbit as a notable exception. Apparently because of the relatively elastic distensible quality of the lower duct in the rabbit, the accumulating sperm simply produced an increasing distension or dilatation of its vas deferens and cauda epididymidis, with little or no change in the upper epididymis. As this distal accumulation and distension progressed over the next months the intact rabbit cauda epididymdis and vas became relatively huge until, beginning at about 6 months after vasectomy, some ducts ruptured focally and formed granulomata (sperm disposal sites). In order to quantify this situation, Moore & Bedford (1978) counted the sperm total accumulating at 1, 2, 4 and 6 months after vasectomy. Somewhat surprisingly even to us, after vasectomy the number of spermatozoa accumulating in the distensible epididymis/vas at each time period was equivalent to the total that would be produced by a normal testis over the same time period – in other words, after vasectomy spermatogenesis had continued at a normal rate over a 6-month period in the rabbit. In both our studies the rabbit testicular weights (one sensitive indicator of function) were similar on the vasectomized and control sides, with the notable exception of occasional animals in which a granuloma had formed high in the epididymis. Regrettably, the conclusion of Kong et al. that vasectomy in the rabbit soon results in testicular damage is incorrect, and the pattern of their own results reinforces this view. The fact that the greatest testicular damage was seen in their study after only 10 days, when sperm accumulation is minimal, suggests that the damage may have resulted not from vasectomy per se but from local trauma or inflammation. This will occur quite readily after exposure of the vas deferens by incision of the skin and processus vaginalis of the rabbit scrotum, rather than via one small central incision in the high inguinal region. Since Kong et al. (2004) quote Bedford (1976) in explaining the testicular damage, it is puzzling that they do not comment also on the very different pattern of the respective results.

A.J. Ladman AAA/Wiley Exemplary Service Award.

A.J. Ladman AAA/Wiley Exemplary Service Award.

Immunohistochemistry of the canine vomeronasal organ

The publisher regrets that in Volume 202, Issue 6 of the Journal of Anatomy, the article Immunohistochemistry of the canine vomeronasal organ by J. C. Dennis et al. was inadvertently printed in black and white. It appears in this issue of the Journal of Anatomy (pp 329338) as it was originally intended.

The mechanics of the first bite.

An analysis of the action of the incisor teeth in humans is presented in terms of the fracture of food particles. It is predicted that the resistance of foods with an essentially linear elastic response to an initial bite by the incisors will depend on the square root of the product of two food properties, Young's modulus and toughness. This quantity should be approximately equal to the product of the stress at cracking during a bite, and the square root of the length of a notch or indentation from which that crack initiates. As a test of the theory, the relationship between in vivo stresses and the depth of incisal penetration, measured during bites on seven 'snack' foods by 10 subjects, and food properties established from mechanical testing, was investigated. Theory and experiment were found to be in excellent agreement. A dimensionless index of the efficiency of incision is suggested, relating fracture performance by subjects to values from a testing machine. This appears to have a high level of inter-subject discrimination with efficiencies varying about threefold. The method appears to have potential applications in dentistry, food science and studies of human and primate evolution.

Erratum

Journal of AnatomyVolume 202, Issue 4 p. 409-409 Free Access Erratum First published: 04 April 2003 https://doi.org/10.1046/j.1469-7580.2003.00182_2.xAboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Unfortunately in the December 2002 issue of the Journal of Anatomy, in the paper by Çavdar et al., the second author’s name is mis-spelled. The correct spelling is Filiz Yılmaz Onat. Reference Çavdar S, Onat FY, Yananli HR, Şehirli US, Tulay C, Saka E, Gürdal E (2002) Cerebellar connections to the rostral reticular nucleus of the thalamus in the rat. J. Anat. 202, 485– 491. Volume202, Issue4April 2003Pages 409-409 ReferencesRelatedInformation

Human Anatomy: Color Atlas and Text

Human Anatomy: Color Atlas and Text

How to make a hand: a 3‐day symposium held at the University of Dundee

Each new individual arises from a single cell which develops into an embryo. One of the most challenging problems is to determine how precise arrangements of cells and tissues are then generated in the embryo to make organs. In this issue we focus on the limb, tracing development from the initial bud to the final complex structure. Until about 10 years ago, little was known about the genetic and molecular basis of vertebrate limb development. This situation has changed dramatically, owing to the combined efforts of developmental biologists and clinical geneticists. Now that we know many of the genes that are required to make a limb, we are beginning to understand how anatomy is generated from the genetic information. This issue of the Journal of Anatomy consists mainly of reviews written by speakers at the ‘How to make a hand’ symposium. We start by considering how limb pattern is specified in the earliest stages of development (Panman & Zeller; Hill et al.) as revealed by powerful genetic studies in mice. Both papers address issues concerning Sonic hedgehog, one of the key genes in establishing the anatomy of the hand. Another gene in the same family, Indian Hedgehog, appears to be responsible for the polydactylous phenotype of a mouse mutant (Crick et al.). The importance of mouse models as informative models for understanding human development is illustrated by the fact that genes employed at these crucial early stages, including Sonic hedgehog, have been found to underlie human conditions in which there are marked anatomical abnormalities of the limb. This topic is considered in more detail by Wilkie, while Miedzybrodzka provides a clinical perspective on one of most common limb abnormalities, clubfoot. One of the crucial issues is how pattern information is translated into tissue organization. Lonai considers the involvement of extracellular matrix in epithelial–mesenchymal interactions in early stages of limb development. Early events establish the organization that leads to the complex anatomy of the vertebrate limb, with precise arrangements of several types of differentiated cells and tissues including cartilage, bone, tendon and muscle. The early skeleton is laid down in cartilage, and Sanz-Ezquerro & Tickle discuss skeletal morphogenesis of the digits with particular reference to experimental work in chick embryos. Buckingham et al. and Francis-West et al. review how limb musculature is established, including the origin of myogenic cells in the somites and muscle differentiation. These two studies, focused on observations in mouse and chick, respectively, together show how studies on different vertebrates are complementary and give added value. In the two research articles published in this issue, Martin & Mackay describe the specialized control of timing of limb development in the opposum Monodelphis; Oldfield & Evans cover tendon development. The limb is supplied with nerves and blood vessels. Turney et al. describe a new chick model for investigating mechanisms involved in limb innnervation. Vargesson addresses the genetic basis of vascularization, concentrating on the importance of TGF beta signalling, while Adams deals with the genes that are now known to be responsible for specifying arteries vs. veins. Finally, the limb must also be covered by skin that acts as a barrier between the internal and external environments, and, importantly in the hand (and foot!), becomes regionally specialized. Byrne et al. provide a detailed review of how the skin develops its barrier function, while Porter reviews the development of hairs, one of the main types of skin appendage. Inherited defects can affect the skin and even be restricted to just the skin on the hands; these are reviewed by McLean. The issue ends with a hypothesis about how the human hand may have evolved for throwing (Young). The February issue of Journal of Anatomy will contain two other review articles from the symposium that address methodology: Sharpe will highlight the possibilities of a new imaging method that could be applied to the developing limb, while Boyde discusses a method of looking at bone architecture.

Allometric analysis beyond heterogeneous regression slopes: use of the Johnson-Neyman technique in comparative biology.

Allometry (or scaling) is a common technique used to evaluate and compare physiological, morphological, and other variables in organisms of different size. The relationship between many variables (Y) and body mass (X) is well described by a power function of the form . Typically, the procedure involves b Y p aX log-transforming both the variable and body mass and calculating a linear regression of the form log (Y ) p log (a) . An advantage of log-linear analysis is that it allows b log (X) calculation of associated 95% confidence intervals for the regression mean and 95% prediction intervals. Furthermore, allometric regressions for two or more groups can be compared. This is often accomplished by ANCOVA (Fisher 1932), a statistical procedure that combines ANOVA and analysis of variance of regressions (ANOVAR) to compare treatment means (groups) after accounting for and removing their relationship with the covariate (often body mass). Generally, ANCOVA is more appropriate for most data than is ANOVA, carried out on ratios of the variable and covariate, because many variables do not have an isometric relationship with body mass (Huxley 1932; Gould 1966; Packard and Boardman 1987, 1988, 1999). A requirement of ANCOVA is that the relationship with the covariate is uniform across groups; that is, the regression slopes (b) must be identical. In practice, before commencing ANCOVA it must therefore be demonstrated that the slopes are not significantly different between groups. When the slopes differ, regression elevations (a) cannot be statistically compared using ANCOVA (Zar 1999). The standard texts on allometry (Peters 1983; Calder 1984; Schmidt-Nielsen 1984; Brown and West 2000) provide little advice on how to continue analysis

Symposium on the respiratory system

The summer 2001 meeting of the Anatomical Society of Great Britain and Ireland was held at University College, Dublin, on 10–12 July, and included a symposium on the biology of the respiratory system. It was the intention of the organizers to assemble a panel of speakers who could give the broadest possible view on this subject. The respiratory system is well suited to such a broad perspective since it has interdependencies with so many other systems as well as a rich phylogenetic and ontogenetic history. This symposium issue of the Journal of Anatomy presents the material covered by each speaker at the meeting. J. N. Maina shows how the comparative morphology of gas exchange mechanisms demonstrates the enormous range of strategies evolved by various taxa to deal with the problems of respiratory exchange under different environmental conditions. In addition to the tissues directly involved in gas exchange, adaptations were also needed in ancillary structures such as the diaphragm, body wall and the musculoskeletal anatomy of the air-conduction passages. M. Pickering and J. F. X. Jones consider how the dual evolutionary origin of the diaphragm is reflected by its current functional anatomy. J. H. Widdicombe gives insights into the complex mechanisms of ciliary action and mucous secretion, an essential requirement for protection of the respiratory epithelia from harmful elements in the external environment of air-breathing vertebrates. Efficient respiration also requires adaptations elsewhere, such as the central nervous and cardiovascular systems, to ensure that the respiratory movements are matched to the metabolic needs of the organism. J. F. R. Paton and M. Dutschmann describe the importance of central control of the glottis for functionally healthy breathing; A. Hislop gives a fascinating account of how the ontogenetic development of the respiratory organs and tissues involves a harmonious interdependence between the development and growth of the respiratory epithelia and that of the vasculature. Demands for adaptation are also made on the mature respiratory system in disease states. As N. Hopkins and P. McLoughlin show, the occurrence of pulmonary hypertension in chronic lung disease raises interesting questions. For example, why does the pulmonary vasculature have a different response to chronic hypoxia compared to the systemic? Is it possible that angiogenesis may occur in the chronically diseased adult lung as a means of modifying hypertension? Is it possible that vascular and other adaptations to disease in the mature lung may be achieved via pathways that are the same as those in normal lung development? We can expect to see efforts to investigate these issues intensifying in the coming years.

The modulation of endothelial cell permeability: winter meeting of the Anatomical Society of Great Britain and Ireland (ASGBI), London, UK, 2-4 January 2002.

In his treatise ‘Longevity and the causes of natural death’De-Martel (1688) wrote: ‘We must therefore enquire into other more true causes of old age and death, which to me seem to be the following. I suppose, that blood is the principle of life, as far as it is vital, that is, in motion by the hot particles contained therein; those who expire by age, do not die for being destitute of blood, but because it ceases to be vital, by reason of too early dissipation of the igneous particles, which in my opinion come to pass, as it doth in wine, which evaporates and loses its strength by the fault of the vessel, which by some opening or other gives passage to what gives virtue to wine. The tunicles and membranes of the veins and arteries which enclose blood, wear in time and wax thin, and their texture gives and breaks in several places, at which apertures the igneous particles abandon the blood. If we have the art to reinforce and strengthen anew the coats and membranes, that they might not let slip what maketh the blood vital, then life would be preserved perpetually.’ More than three centuries later, despite the discovery of key adhesion molecules which bind endothelial cells together, surface receptors which phosphorylate upon occupation and intracellular signalling molecules, we are still far from understanding the signalling pathways which modulate endothelial permeability. In fact the very transport pathways used, paracellular or transcellular, are still a matter of debate. During inflammatory events, does increased permeability result from opening of paracellular junctions or the formation of vesicular channels from luminal to abluminal surfaces? Moreover, within the paracellular pathway, the role of tight junctions and adherens junctions in determining barrier properties varies according to location of the vascular bed. In the blood–brain barrier, it is clear that the tight junctions, with a complex network of continuous junctional strands, control permeability. The role of tight junctions becomes accessory in systemic vessels where adherens junctions predominate in the paracellular clefts. Transgenic animal and in vitro studies have shown that molecules present in adherens junctions have a significant impact on both vascular permeability and angiogenesis. The discovery of a family of water channel proteins, the aquaporins, which are expressed in many endothelial and epithelia, has spawned research into another important mechanism by which fluid is transported across these cells. The molecules present in cell–cell and cell–matrix junctions clearly have functions beyond adhesion, being important signal transduction ligands vulnerable to both ‘inside-out’ and ‘outside-in’ signalling. In addition to inflammatory mediators such as histamine, hydrogen peroxide, thrombin and bradykinin, the so-called angiogenic growth factors VEGF and angiopoietins have clearly demonstrable roles in influencing vascular permeability and determining junctional integrity. VEGF is also an important survival factor. Where and whether the signalling pathways determining angiogenesis, endothelial survival and permeability meet may be the quest of the early years of the 21st century. Only then will it be possible to develop therapeutic interventions that can restore vascular integrity – a goal held so dear by de Martel. The clinical benefits of such interventions will be enormous, since many conditions (e.g. diabetic microangiopathy, sepsis, ischaemia and neoplasia to name but a few) all feature impaired endothelial permeability in their symptomatology. The symposium brought together anatomists, molecular biologists and physiologists to develop an integrated view of endothelial cell permeability. The reviews presented in this volume describe some of the recent exciting advances in the field of endothelial cell biology and provide a synthesis of molecular and structural approaches to understanding endothelial permeability. We believe that the contents of this volume will be widely cited and we were privileged to be able to organize the symposium and edit this thought-provoking issue of the Journal of Anatomy.