scholarly journals Insects Provide Unique Systems to Investigate How Early-Life Experience Alters the Brain and Behavior

2021 ◽  
Vol 15 ◽  
Author(s):  
Rebecca R. Westwick ◽  
Clare C. Rittschof

Early-life experiences have strong and long-lasting consequences for behavior in a surprising diversity of animals. Determining which environmental inputs cause behavioral change, how this information becomes neurobiologically encoded, and the functional consequences of these changes remain fundamental puzzles relevant to diverse fields from evolutionary biology to the health sciences. Here we explore how insects provide unique opportunities for comparative study of developmental behavioral plasticity. Insects have sophisticated behavior and cognitive abilities, and they are frequently studied in their natural environments, which provides an ecological and adaptive perspective that is often more limited in lab-based vertebrate models. A range of cues, from relatively simple cues like temperature to complex social information, influence insect behavior. This variety provides experimentally tractable opportunities to study diverse neural plasticity mechanisms. Insects also have a wide range of neurodevelopmental trajectories while sharing many developmental plasticity mechanisms with vertebrates. In addition, some insects retain only subsets of their juvenile neuronal population in adulthood, narrowing the targets for detailed study of cellular plasticity mechanisms. Insects and vertebrates share many of the same knowledge gaps pertaining to developmental behavioral plasticity. Combined with the extensive study of insect behavior under natural conditions and their experimental tractability, insect systems may be uniquely qualified to address some of the biggest unanswered questions in this field.

2014 ◽  
Vol 16 (1) ◽  
pp. 29-41 ◽  

Risk for adult psychiatric disorders is partially determined by early-life alterations occurring during neural circuit formation and maturation. In this perspective, recent data show that the serotonin system regulates key cellular processes involved in the construction of cortical circuits. Translational data for rodents indicate that early-life serotonin dysregulation leads to a wide range of behavioral alterations, ranging from stress-related phenotypes to social deficits. Studies in humans have revealed that serotonin-related genetic variants interact with early-life stress to regulate stress-induced cortisol responsiveness and activate the neural circuits involved in mood and anxiety disorders. Emerging data demonstrate that early-life adversity induces epigenetic modifications in serotonin-related genes. Finally, recent findings reveal that selective serotonin reuptake inhibitors can reinstate juvenile-like forms of neural plasticity, thus allowing the erasure of long-lasting fear memories. These approaches are providing new insights on the biological mechanisms and clinical application of antidepressants.


Author(s):  
Christopher Rosenmeier

Xu Xu and Wumingshi were among the most widely read authors in China during and after the Second Sino-Japanese War (1937–1945). Despite being an integral part of the Chinese literary scene, their bestselling fiction has, however, been given scant attention in histories of Chinese writing. This book is the first extensive study of Xu Xu and Wumingshi in English or any other Western language and it re-establishes their importance within the popular Chinese literature of the 1940s. Their romantic novels and short stories were often set abroad and featured a wide range of stereotypes, from pirates, spies and patriotic soldiers to ghosts, spirits and exotic women who confounded the mostly cosmopolitan male protagonists. Christopher Rosenmeier’s detailed analysis of these popular novels and short stories shows that such romances broke new ground by incorporating and adapting narrative techniques and themes from the Shanghai modernist writers of the 1930s, notably Shi Zhecun and Mu Shiying. The study thereby contests the view that modernism had little lasting impact on Chinese fiction, and it demonstrates that the popular literature of the 1940s was more innovative than usually imagined, with authors, such as those studied here, successfully crossing the boundaries between the popular and the elite, as well as between romanticism and modernism, in their bestselling works.


Author(s):  
Mary Jane West-Eberhard

The first comprehensive synthesis on development and evolution: it applies to all aspects of development, at all levels of organization and in all organisms, taking advantage of modern findings on behavior, genetics, endocrinology, molecular biology, evolutionary theory and phylogenetics to show the connections between developmental mechanisms and evolutionary change. This book solves key problems that have impeded a definitive synthesis in the past. It uses new concepts and specific examples to show how to relate environmentally sensitive development to the genetic theory of adaptive evolution and to explain major patterns of change. In this book development includes not only embryology and the ontogeny of morphology, sometimes portrayed inadequately as governed by "regulatory genes," but also behavioral development and physiological adaptation, where plasticity is mediated by genetically complex mechanisms like hormones and learning. The book shows how the universal qualities of phenotypes--modular organization and plasticity--facilitate both integration and change. Here you will learn why it is wrong to describe organisms as genetically programmed; why environmental induction is likely to be more important in evolution than random mutation; and why it is crucial to consider both selection and developmental mechanism in explanations of adaptive evolution. This book satisfies the need for a truly general book on development, plasticity and evolution that applies to living organisms in all of their life stages and environments. Using an immense compendium of examples on many kinds of organisms, from viruses and bacteria to higher plants and animals, it shows how the phenotype is reorganized during evolution to produce novelties, and how alternative phenotypes occupy a pivotal role as a phase of evolution that fosters diversification and speeds change. The arguments of this book call for a new view of the major themes of evolutionary biology, as shown in chapters on gradualism, homology, environmental induction, speciation, radiation, macroevolution, punctuation, and the maintenance of sex. No other treatment of development and evolution since Darwin's offers such a comprehensive and critical discussion of the relevant issues. Developmental Plasticity and Evolution is designed for biologists interested in the development and evolution of behavior, life-history patterns, ecology, physiology, morphology and speciation. It will also appeal to evolutionary paleontologists, anthropologists, psychologists, and teachers of general biology.


Studies of animal behavior often assume that all members of a species exhibit the same behavior. Geographic Variation in Behavior shows that, on the contrary, there is substantional variation within species across a wide range of taxa. Including work from pioneers in the field, this volume provides a balanced overview of research on behavioral characteristics that vary geographically. The authors explore the mechanisms by which behavioral differences evolve and examine related methodological issues. Taken together, the work collected here demonstrates that genetically based geographic variation may be far more widespread than previously suspected. The book also shows how variation in behavior can illuminate both behavioral evolution and general evolutionary patterns. Unique among books on behavior in its emphasis on geographic variation, this volume is a valuable new resource for students and researchers in animal behavior and evolutionary biology.


Author(s):  
Karen D. Williams ◽  
Marla B. Sokolowski

Why is there so much variation in insect behavior? This chapter will address the sources of behavioral variability, with a particular focus on phenotypic plasticity. Variation in social, nutritional, and seasonal environmental contexts during development and adulthood can give rise to phenotypic plasticity. To delve into mechanism underlying behavioral flexibility in insects, examples of polyphenisms, a type of phenotypic plasticity, will be discussed. Selected examples reveal that environmental change can affect gene expression, which in turn can affect behavioral plasticity. These changes in gene expression together with gene-by-environment interactions are discussed to illuminate our understanding of insect behavioral plasticity.


Author(s):  
Meg Dennison ◽  
Katie McLaughlin

Early-life adversity is associated with elevated risk for a wide range of mental disorders across the lifespan, including those that involve disruptions in positive emotionality. Although extensive research has evaluated heightened negative emotionality and threat processing as developmental mechanisms linking early-life adversity with mental health problems, emerging evidence suggests that positive emotions play an integral, but complex, role in the association of early-life adversity with psychopathology. This chapter identifies two pathways through which positive emotion influences risk for psychopathology following early-life adversity. First, experiences of early-life adversity may alter the development of the “positive valence system”, which in turn increases risk for psychopathology. Second, the association between adversity and psychopathology may vary as a function of individual differences in positive emotionality. We consider how the development of positive emotionality—measured at psychological, behavioral and neurobiological levels—may be altered by early-life adversity, creating a diathesis for psychopathology. We additionally review evidence for the role of positive emotion, measured at multiple levels, as a protective factor that buffers against the adverse impacts of adversity. In integrating these two roles, it is proposed that characteristics of environmental adversity, including developmental timing, duration, and type of adversity, may differentially impact the development of positive emotionality, leading to a better understanding of risks associated with specific adverse experiences. Methodological issues regarding the measurement of adverse environments as well as implications for early intervention and treatment are discussed.


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