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Current Biology : CB Dec 2018Multicellular organisms rely on cell-to-cell communication and resource exchange to coordinate the various diverse processes involved in growth, development, and...
Multicellular organisms rely on cell-to-cell communication and resource exchange to coordinate the various diverse processes involved in growth, development, and environmental responses across tissues and organs. Most complex multicellular organisms have highly organised and specialised anatomies, which develop by processes underpinned by regulated mechanisms for intercellular coordination. Indeed, in 1897 Wilhelm Pfeffer noted that for a plant to coordinate its physiological responses across the whole, there must be continuity throughout the entire organism, and that connections between cells must transport material and messages between tissues. Intercellular communication is an integral factor in any tissue-wide or organ-wide process in a multicellular organism.
Topics: Cell Membrane; Plant Physiological Phenomena; Plasmodesmata
PubMed: 30562524
DOI: 10.1016/j.cub.2018.11.004 -
Disease Models & Mechanisms Mar 2022Whole-body health relies on complex inter-organ signalling networks that enable organisms to adapt to environmental perturbations and to changes in tissue homeostasis.... (Review)
Review
Whole-body health relies on complex inter-organ signalling networks that enable organisms to adapt to environmental perturbations and to changes in tissue homeostasis. The intestine plays a major role as a signalling centre by producing local and systemic signals that are relayed to the body and that maintain intestinal and organismal homeostasis. Consequently, disruption of intestinal homeostasis and signalling are associated with systemic diseases and multi-organ dysfunction. In recent years, the fruit fly Drosophila melanogaster has emerged as a prime model organism to study tissue-intrinsic and systemic signalling networks of the adult intestine due to its genetic tractability and functional conservation with mammals. In this Review, we highlight Drosophila research that has contributed to our understanding of how the adult intestine interacts with its microenvironment and with distant organs. We discuss the implications of these findings for understanding intestinal and whole-body pathophysiology, and how future Drosophila studies might advance our knowledge of the complex interplay between the intestine and the rest of the body in health and disease.
Topics: Animals; Drosophila; Drosophila melanogaster; Homeostasis; Intestines; Mammals; Signal Transduction
PubMed: 35344037
DOI: 10.1242/dmm.049332 -
EMBO Reports Sep 2019Multidirectional interactions between metabolic organs in the periphery and the central nervous system have evolved concomitantly with multicellular organisms to... (Review)
Review
Multidirectional interactions between metabolic organs in the periphery and the central nervous system have evolved concomitantly with multicellular organisms to maintain whole-body energy homeostasis and ensure the organism's adaptation to external cues. These interactions are altered in pathological conditions such as obesity and type 2 diabetes. Bioactive peptides and proteins, such as hormones and cytokines, produced by both peripheral organs and the central nervous system, are key messengers in this inter-organ communication. Despite the early discovery of the first hormones more than 100 years ago, recent studies taking advantage of novel technologies have shed light on the multiple ways used by cells in the body to communicate and maintain energy balance. This review briefly summarizes well-established concepts and focuses on recent advances describing how specific proteins and peptides mediate the crosstalk between gut, brain, and other peripheral metabolic organs in order to maintain energy homeostasis. Additionally, this review outlines how the improved knowledge about these inter-organ networks is helping us to redefine therapeutic strategies in an effort to promote healthy living and fight metabolic disorders and other diseases.
Topics: Animals; Diabetes Mellitus, Type 2; Energy Metabolism; Homeostasis; Humans; Models, Biological; Obesity
PubMed: 31423716
DOI: 10.15252/embr.201947903 -
Frontiers in Cell and Developmental... 2017The long-term maintenance of an organism's homeostasis and health relies on the accurate regulation of organ-organ communication. Recently, there has been growing... (Review)
Review
The long-term maintenance of an organism's homeostasis and health relies on the accurate regulation of organ-organ communication. Recently, there has been growing interest in using the gastrointestinal tract to elucidate the regulatory programs that underlie the complex interactions between organs. Data obtained in this field have dramatically improved our understanding of how organ-organ communication contributes to the regulation of various aspects of the intestine, including its metabolic and physiological status. However, although research uncovering regulatory programs associated with interorgan communication has provided key insights, the underlying mechanisms have not been extensively explored. In this review, we highlight recent findings describing gut-neighbor and neighbor-neighbor communication models in adults and larvae, respectively, with a special focus on how a range of critical strategies concerning continuous interorgan communication and adjustment can be used to manipulate different aspects of biological processes. Given the high degree of similarity between the and mammalian intestinal epithelia, it can be anticipated that further analyses of the gastrointestinal tract will facilitate the discovery of similar mechanisms underlying organ-organ communication in other mammalian organs, such as the human intestine.
PubMed: 28421183
DOI: 10.3389/fcell.2017.00029 -
The Journal of the Acoustical Society... May 2023As the ecological importance of gelatinous organisms becomes increasingly appreciated, so has the need for improved knowledge of their abundance and distribution....
As the ecological importance of gelatinous organisms becomes increasingly appreciated, so has the need for improved knowledge of their abundance and distribution. Acoustic backscattering measurements are routine for fisheries assessments but are not yet widely used to survey populations of gelatinous zooplankton. The use of acoustic backscattering techniques to understand the distribution and abundance of organisms requires an understanding of their target strength (TS). This study presents a framework for a sound scattering model for jellyfish based on the Distorted Wave Born Approximation that incorporates size, shape, and material properties of individual organisms. This model, with a full three-dimensional shape rendition, is applied to a common species of scyphomedusa (Chrysaora chesapeakei) and verified experimentally with broadband (52-90 and 93-161 kHz) laboratory TS measurements of live individuals. Cyclical changes in the organism's shape due to swimming kinematics were examined, as well as averages over swimming position and comparisons with scattering from simpler shapes. The model predicts overall backscattering levels and broad spectral behavior within <2 dB. Measured TS exhibits greater variability than is predicted by scaling the size of the organism in the scattering model, showing that density and sound speed vary among individuals.
Topics: Humans; Acoustics; Fisheries; Gelatin; Sound; Swimming
PubMed: 37222723
DOI: 10.1121/10.0019577 -
European Journal of Clinical Nutrition Feb 2019Body mass in humans and animals is strongly associated with the rate of heat production as defined by resting energy expenditure (REE). Beginning with the ancient Greeks... (Review)
Review
Body mass in humans and animals is strongly associated with the rate of heat production as defined by resting energy expenditure (REE). Beginning with the ancient Greeks up to the present time, philosophers and scientists have endeavored to understand the nature and sources of bodily heat. Today we recognize that body mass consists of organs and tissues, each of which produces a specified amount of heat at rest. An individual organ's REE can now be estimated in vivo as the product of its assumed mass-specific metabolic rate and its imaging-derived mass; whole-body REE reflects the sum of organ and tissue metabolic rates. The sizes of organs and total body mass in adults are governed by two main factors, a person's stature or height, and their level of adiposity. With greater body size, as represented by adult height independent of adiposity, organs remain stable or increase in mass according to distinct "scaling" patterns. Similarly, with greater relative adiposity organs adaptively accommodate to the increase in imposed mechanical and metabolic loading conditions. Through a detailed analysis of these stature and adiposity effects, we show how classical statistical REE prediction models can be mechanistically understood at the anatomic body composition level.
Topics: Body Composition; Energy Metabolism; Humans
PubMed: 30254244
DOI: 10.1038/s41430-018-0319-3 -
High Altitude Medicine & Biology Sep 2014Epigenetics refers to long-term modifications of gene activity that can be inherited, either somatically or transgenerationally, but that are independent of alterations... (Review)
Review
Epigenetics refers to long-term modifications of gene activity that can be inherited, either somatically or transgenerationally, but that are independent of alterations in the primary base sequence of the organism's DNA. These changes can include chemical modifications of both the DNA bases and the proteins that associate with the DNA helices to form chromatin, the nucleic acid:protein complex of which the chromosomes are comprised. Epigenetic modifications can affect the accessibility of the DNA for transcription factors (the DNA-binding proteins that specify which genes are to be active or silent by modulating the recruitment of the transcriptional machinery that reads the information encoded in the sequence) and thereby regulate the expression of genes and alter the phenotype of the organism. Epigenetic marks can also be re-established following mitosis, allowing patterns of differential gene expression to be transmitted from one cell generation to the next, and can even be maintained through meiosis, allowing transgenerational transfer of regulatory cues. Unlike the information encoded in the DNA sequence, which is invariant between most cell types and over time, epigenetic information is tissue specific and can change in response to exogenous and endogenous perturbations. This responsive capacity enables a sensitive and reactive system that can optimize gene expression in relevant tissue in response to environmental change. The realization that organisms are capable of genetically 'reprograming' themselves as well as 'preprograming' future cells, and even future offspring to optimize gene expression for a given environment may have tremendous ramifications on our understanding of both acclimatization and adaptation to hypoxia.
Topics: Acclimatization; Altitude; Altitude Sickness; DNA Methylation; Epigenesis, Genetic; Gene Expression Regulation; Genetic Markers; Histones; Humans; Hypoxia; Twin Studies as Topic
PubMed: 25184852
DOI: 10.1089/ham.2014.1016 -
Physics of Life Reviews Dec 2014The term "personality" is used to describe a distinctive and relatively stable set of mental traits that aim to explain the organism's behavior. The concept of... (Review)
Review
The term "personality" is used to describe a distinctive and relatively stable set of mental traits that aim to explain the organism's behavior. The concept of personality that emerged in human psychology has been also applied to the study of non-human organisms from birds to horses. In this paper, I critically review the concept of personality from an interdisciplinary perspective, and point to some ideas that may be used for developing a cognitive-biological theory of personality. Integrating theories and research findings from various fields such as cognitive ethnology, clinical psychology, and neuroscience, I argue that the common denominator of various personality theories are neural systems of threat/trust management and their emotional, cognitive, and behavioral dimensions. In this context, personality may be also conceived as a meta-heuristics both human and non-human organisms apply to model and predict the behavior of others. The paper concludes by suggesting a minimal computational model of personality that may guide future research.
Topics: Cognition; Computer Simulation; Emotions; Humans; Interdisciplinary Communication; Models, Biological; Models, Psychological; Neurosciences; Personality; Personality Disorders; Social Behavior; Thinking; Trust
PubMed: 25308343
DOI: 10.1016/j.plrev.2014.09.002 -
Neural Computation Feb 2023In this view, we address the problem of consciousness, and although we focus on its human presentation, we note that the phenomenon is present in numerous nonhuman...
In this view, we address the problem of consciousness, and although we focus on its human presentation, we note that the phenomenon is present in numerous nonhuman species and use findings from a variety of animal studies to explain our hypothesis for how consciousness is made. Consciousness occurs when mind contents, such as perceptions and thoughts, are spontaneously identified as belonging to a specific organism/owner. Conscious minds are said to have a self that experiences mental events. We hypothesize that the automatic identification that associates minds and organisms is provided by a continuous flow of homeostatic feelings. Those feelings arise from the uninterrupted process of life regulation and correspond to both salient physiological fluctuations such as hunger, pain, well-being, or malaise, as well as to states closer to metabolic equilibrium and best described as feelings of life/existence, such as breathing or body temperature. We also hypothesize that homeostatic feelings were the inaugural phenomena of consciousness in biological evolution and venture that they were selected because the information they provided regarding the current state of life regulation conferred extraordinary advantages to the organisms so endowed. The "knowledge" carried by conscious homeostatic feelings provided "overt" guidance for life regulation, an advance over the covert regulation present in nonconscious organisms. Finally, we outline a mechanism for the generation of feelings based on a two-way interaction between interoceptive components of the nervous system and a particular set of nonneural components of the organism's interior, namely, viscera and circulating chemical molecules involved in their operations. Feelings emerge from this interaction as continuous and hybrid phenomena, related simultaneously to two series of events. The first is best described by the terms neural/representational/and mental and the second by the terms nonneural/visceral/and chemical. We note that this account offers a solution for the mind-body problem: homeostatic feelings constitute the "mental" version of bodily processes.
Topics: Animals; Humans; Consciousness; Biological Evolution
PubMed: 35896152
DOI: 10.1162/neco_a_01521 -
Bone Feb 2019Hematopoiesis in land dwelling vertebrates and marine mammals occurs within the bone marrow, continually providing mature progeny over the course of an organism's... (Review)
Review
Hematopoiesis in land dwelling vertebrates and marine mammals occurs within the bone marrow, continually providing mature progeny over the course of an organism's lifetime. This conserved dependency highlights the critical relationship between these two organs, yet the skeletal and hematopoietic systems are often thought of as separate. In fact, data are beginning to show that skeletal disease pathogenesis influences hematopoiesis and viceversa, offering novel opportunities to approach disease affecting bone and blood. With a growing global population of aged individuals, interest has focused on cell autonomous changes in hematopoietic and skeletal systems that result in dysfunction. The purpose of this review is to summarize the literature on aging effects in both fields, and provide critical examples of organ cross-talk in the aging process.
Topics: Aging; Animals; Bone Marrow; Bone and Bones; Hematopoiesis; Hematopoietic Stem Cells; Humans; Signal Transduction
PubMed: 30010082
DOI: 10.1016/j.bone.2018.07.012