scholarly journals Regulation of Morphological and Functional Aspects of Sexual Dimorphism in the Brain

2021 ◽  
Author(s):  
Chitose Orikasa
Keyword(s):  
Sexual Dimorphism ◽  
Sex Steroids ◽  
Perinatal Period ◽  
Adult Brain ◽  
Functional Aspects ◽  
Neuronal Functions ◽  
And Control ◽  
The Brain ◽  
Neuroendocrine Functions

Sexual dimorphism of the adult brain regulates sex-dependent functions including reproductive and neuroendocrine activities in rodents. It is determined by sex steroid hormones during a critical perinatal period in female and male rodents. Sex steroids act on each nuclear receptor in the brain and control different physiological and neuroendocrine functions and behaviors. Several regions of the brain show evident morphological sex differences that are involved in their physiological functions. This review addresses and focuses largely on the role of sex-dependent differences in the brain, and their crucial functions in animal models. Particularly, recent intriguing data concerning the diversity of neuronal functions and sexual dimorphism are discussed.

Sex steroids-induced neurogenesis in adult brain: a better look at mechanisms and mediators

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamideh Abotalebi ◽  
Babak Ebrahimi ◽  
Raziyeh Shahriyari ◽  
Reyhaneh Shafieian
Keyword(s):  
Sex Steroids ◽  
Ventricular Zone ◽  
Mammalian Species ◽  
Adult Brain ◽  
Sex Steroid ◽  
Subgranular Zone ◽  
Human Beings ◽  
The Relationship ◽  
The Brain

Abstract Adult neurogenesis is the production of new nerve cells in the adult brain. Neurogenesis is a clear example of the neuroplasticity phenomenon which can be observed in most of mammalian species, including human beings. This phenomenon occurs, at least, in two regions of the brain: the subgranular zone of the dentate gyrus in hippocampus and the ventricular zone of lateral ventricles. Numerous studies have investigated the relationship between sex steroid hormones and neurogenesis of adult brain; of which, mostly concentrated on the role of estradiol. It has been shown that estrogen plays a significant role in this process through both classic and non-classic mechanisms, including a variety of different growth factors. Therefore, the objective of this review is to investigate the role of female sex steroids with an emphasis on estradiol and also its potential implications for regulating the neurogenesis in the adult brain.

scholarly journals The Role of Iron in the Pathogenesis of Autism Spectrum Disorders in Children

2018 ◽  
Vol 17 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Olga V. Kostina
Keyword(s):  
Autism Spectrum Disorders ◽  
Iron Metabolism ◽  
Biochemical Parameters ◽  
Children With Autism ◽  
Neuropsychiatric Disorders ◽  
Perinatal Period ◽  
Autism Spectrum ◽  
Spectrum Disorders ◽  
The Brain

The review presents an analysis of the mechanisms of iron effect on the brain development. The importance of iron deficiency in the perinatal period is considered as a risk factor for the development of neuropsychiatric disorders in children with autism spectrum disorders (ASDs). Possible causes of sideropenia are discussed; data on haematological and biochemical parameters characterizing iron metabolism in children with ASDs are presented. The demand for studying the role of iron metabolism imbalance in the development of neuropsychiatric disorders in order to clarify pathogenetic mechanisms of ASDs and to determine methods for their correction is emphasized.

scholarly journals An Emerging Role of m6A in Memory: A Case for Translational Priming

2020 ◽  
Vol 21 (20) ◽  
pp. 7447
Author(s):  
Amanda M. Leonetti ◽  
Ming Yin Chu ◽  
Fiona O. Ramnaraign ◽  
Samuel Holm ◽  
Brandon J. Walters
Keyword(s):  
Learning And Memory ◽  
Memory Consolidation ◽  
Protein Translation ◽  
Memory Formation ◽  
Current Data ◽  
Neuron Development ◽  
Neuronal Functions ◽  
The Brain ◽  
Fine Tune

Investigation into the role of methylation of the adenosine base (m6A) of RNA has only recently begun, but it quickly became apparent that m6A is able to control and fine-tune many aspects of mRNA, from splicing to translation. The ability of m6A to regulate translation distally, away from traditional sites near the nucleus, quickly caught the eye of neuroscientists because of implications for selective protein translation at synapses. Work in the brain has demonstrated how m6A is functionally required for many neuronal functions, but two in particular are covered at length here: The role of m6A in 1) neuron development; and 2) memory formation. The purpose of this review is not to cover all data about m6A in the brain. Instead, this review will focus on connecting mechanisms of m6A function in neuron development, with m6A’s known function in memory formation. We will introduce the concept of “translational priming” and discuss how current data fit into this model, then speculate how m6A-mediated translational priming during memory consolidation can regulate learning and memory locally at the synapse.

scholarly journals Molecular and Cellular Impact of Inflammatory Extracellular Vesicles (EVs) Derived from M1 and M2 Macrophages on Neural Action Potentials

2020 ◽  
Vol 10 (7) ◽  
pp. 424
Author(s):  
Sarah Vakili ◽  
Taha Mohseni Ahooyi ◽  
Shadan S. Yarandi ◽  
Martina Donadoni ◽  
Jay Rappaport ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Immune Cells ◽  
Action Potentials ◽  
M2 Macrophage ◽  
M2 Macrophages ◽  
Neuronal Functions ◽  
The Brain ◽  
Macrophage Subtypes ◽  
M1 And M2 Macrophages

Several factors can contribute to neuroinflammatory disorders, such as cytokine and chemokines that are produced and released from peripherally derived immune cells or from locally activated cells such as microglia and perivascular macrophages in the brain. The primary function of these cells is to clear inflammation; however, following inflammation, circulating monocytes are recruited to the central nervous system (CNS). Monocyte-derived macrophages in the CNS play pivotal roles in mediating neuroinflammatory responses. Macrophages are heterogeneous both in normal and in pathological conditions due to their plasticity, and they are classified in two main subsets, classically activated (M1) or alternatively activated (M2). There is accumulating evidence suggesting that extracellular vesicles (EVs) released from activated immune cells may play crucial roles in mediating inflammation. However, a possible role of EVs released from immune cells such as M1 and M2 macrophages on neuronal functions in the brain is not known. In order to investigate the molecular and cellular impacts of macrophages and EVs released from macrophage subtypes on neuronal functions, we used a recently established in vitro M1 and M2 macrophage culture model and isolated and characterized EVs from these macrophage subtypes, treated primary neurons with M1 or M2 EVs, and analyzed the extracellular action potentials of neurons with microelectrode array studies (MEA). Our results introduce evidence on the interfering role of inflammatory EVs released from macrophages in interneuronal signal transmission processes, with implications in the pathogenesis of neuroinflammatory diseases induced by a variety of inflammatory insults.

scholarly journals Chemokines and chemokine receptors in the brain: implication in neuroendocrine regulation

2007 ◽  
Vol 38 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Céline Callewaere ◽  
Ghazal Banisadr ◽  
William Rostène ◽  
Stéphane Mélik Parsadaniantz
Keyword(s):  
Chemokine Receptors ◽  
Cell Types ◽  
Normal Brain ◽  
Ability To Act ◽  
The Central Nervous System ◽  
Neuronal Functions ◽  
The Brain ◽  
Neuroendocrine Functions

Chemokines are small secreted proteins that chemoattract and activate immune and non-immune cells both in vivo and in vitro. In addition to their well-established role in the immune system, several recent reports have suggested that chemokines and their receptors may also play a role in the central nervous system (CNS). The best known central action is their ability to act as immunoinflammatory mediators. Indeed, these proteins regulate leukocyte infiltration in the brain during inflammatory and infectious diseases. However, we and others recently demonstrated that they are expressed not only in neuroinflammatory conditions, but also constitutively by different cell types including neurons in the normal brain, suggesting that they may act as modulators of neuronal functions. The goal of this review is to highlight the role of chemokines in the control of neuroendocrine functions. First, we will focus on the expression of chemokines and their receptors in the CNS, with the main spotlight on the neuronal expression in the hypothalamo–pituitary system. Secondly, we will discuss the role – we can now suspect – of chemokines and their receptors in the regulation of neuroendocrine functions. In conclusion, we propose that chemokines can be added to the well-described neuroendocrine regulatory mechanisms, providing an additional fine modulatory tuning system in physiological conditions.

scholarly journals Authority and Universalism: Conventional Values in Descriptive Catalog Code

NASKO ◽  
2017 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Brian Dobreski
Keyword(s):  
Historical Analysis ◽  
Initial Step ◽  
Knowledge Organization ◽  
Human Welfare ◽  
Social Exchanges ◽  
Power And Control ◽  
Functional Aspects ◽  
Anglo American ◽  
And Control

Every standard embodies a particular set of values. Some aspects are privileged while others are masked. Values embedded within knowledge organization standards have special import in that they are further perpetuated by the data they are used to generate. Within libraries, descriptive catalog codes serve as prominent knowledge organization standards, guiding the creation of resource representations. Though the historical and functional aspects of these standards have received significant attention, less focus has been placed on the values associated with such codes. In this study, a critical, historical analysis of ten Anglo- American descriptive catalog codes and surrounding discourse was conducted as an initial step towards uncovering key values associated with this lineage of standards. Two values in particular were found to be highly significant: authority and universalism. Authority is closely tied to notions of power and control, particularly over practice or belief. Increasing control over resources, identities, and viewpoints are all manifestations of the value of authority within descriptive codes. Universalism has guided the widening coverage of descriptive codes in regards to settings and materials, such as the extension of bibliographic standards to non-book resources. Together, authority and universalism represent conventional values focused on facilitating orderly social exchanges. A comparative lack of emphasis on values concerning human welfare and empowerment may be unsurprising, but raises questions concerning the role of human values in knowledge organization standards. Further attention to the values associated with descriptive codes and other knowledge organization standards is important as libraries and other institutions seek to share their resource representation data more widely.

scholarly journals Gonadectomy and blood sampling procedures in small size teleost models

2020 ◽  
Author(s):  
Muhammad Rahmad Royan ◽  
Shinji Kanda ◽  
Daichi Kayo ◽  
Weiyi Song ◽  
Wei Ge ◽  
...  
Keyword(s):  
Sex Steroids ◽  
Teleost Fish ◽  
Oryzias Latipes ◽  
Blood Sampling ◽  
Model Organisms ◽  
Small Fish ◽  
Neuroendocrine Control ◽  
Sampling Procedures ◽  
The Brain

AbstractSex steroids, produced by the gonads, play an essential role in the neuroendocrine control of reproduction in all vertebrates by providing feedback to the brain and pituitary. Sex steroids also play an important role in tissue plasticity by regulating cell proliferation in several tissues including the brain and the pituitary. Therefore, investigating the role of sex steroids and mechanisms by which they act is crucial to better understand both feedback mechanism and tissue plasticity. Teleost fish, which possess a higher degree of tissue plasticity and variations in reproduction strategies compared to mammals, appear to be useful models to investigate these questions. The removal of the main source of sex steroid production using gonadectomy together with blood sampling to measure steroid levels, have been well-established and fairly feasible in bigger fish and are powerful techniques to investigate the role and effects of sex steroids. However, small fish such as zebrafish and medaka, which are particularly good model organisms considering the well-developed genetic toolkit and the numerous protocols available to investigate their biology and physiology, raise challenges for applying such protocols due to their small size. Here, we demonstrate the step-by-step procedure of gonadectomy in both males and females followed by blood sampling in a small sized teleost model, the Japanese medaka (Oryzias latipes). The use of these procedures combined with the other advantages of using these small teleost models will greatly improve our understanding of feedback mechanisms in the neuroendocrine control of reproduction and tissue plasticity provided by sex steroids in vertebrates.SUMMARYThe article describes a quick protocol to gonadectomize and sample blood from small teleost fish, using medaka (Oryzias latipes) as a model, to investigate the role of sex steroids in animal physiology.

scholarly journals Dehydroepiandrosterone Metabolism by 3β-Hydroxysteroid Dehydrogenase/Δ5-Δ4 Isomerase in Adult Zebra Finch Brain: Sex Difference and Rapid Effect of Stress

Endocrinology ◽  
2004 ◽  
Vol 145 (4) ◽  
pp. 1668-1677 ◽  
Author(s):  
Kiran K. Soma ◽  
Noel A. Alday ◽  
Michaela Hau ◽  
Barney A. Schlinger
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Zebra Finch ◽  
Sex Steroids ◽  
Hydroxysteroid Dehydrogenase ◽  
Adult Brain ◽  
Brain And Behavior ◽  
Rapid Modulation ◽  
And Behavior ◽  
The Brain

Abstract Dehydroepiandrosterone (DHEA) is a precursor to sex steroids such as androstenedione (AE), testosterone (T), and estrogens. DHEA has potent effects on brain and behavior, although the mechanisms remain unclear. One possible mechanism of action is that DHEA is converted within the brain to sex steroids. 3β-Hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) catalyzes the conversion of DHEA to AE. AE can then be converted to T and estrogen within the brain. We test the hypothesis that 3β-HSD is expressed in the adult brain in a region- and sex-specific manner using the zebra finch (Taeniopygia guttata), a songbird with robust sex differences in song behavior and telencephalic song nuclei. In zebra finch brain, DHEA is converted by 3β-HSD to AE and subsequently to estrogens and 5α- and 5β-reduced androgens. 3β-HSD activity is highest in the diencephalon and telencephalon. In animals killed within 2–3 min of disturbance, baseline 3β-HSD activity in portions of the telencephalon is higher in females than males. Acute restraint stress (10 min) decreases 3β-HSD activity in females but not in males, and in stressed animals, telencephalic 3β-HSD activity is greater in males than in females. Thus, the baseline sex difference is rapidly reversed by stress. To our knowledge, this is the first demonstration of 1) brain region differences in DHEA metabolism by 3β-HSD, 2) rapid modulation of 3β-HSD activity, and 3) sex differences in brain 3β-HSD and regulation by stress. Songbirds are good animal models for studying the regulation and functions of DHEA and neurosteroids in the nervous system.

scholarly journals Hypothalamic control of the male neonatal testosterone surge

2016 ◽  
Vol 371 (1688) ◽  
pp. 20150115 ◽  
Author(s):  
Jenny Clarkson ◽  
Allan E. Herbison
Keyword(s):  
Preoptic Area ◽  
Neonatal Period ◽  
Perinatal Period ◽  
Neuron Activity ◽  
Specific Population ◽  
Hypothalamic Control ◽  
Gnrh Neurons ◽  
Male Specific ◽  
The Brain

Sex differences in brain neuroanatomy and neurophysiology underpin considerable physiological and behavioural differences between females and males. Sexual differentiation of the brain is regulated by testosterone secreted by the testes predominantly during embryogenesis in humans and the neonatal period in rodents. Despite huge advances in understanding how testosterone, and its metabolite oestradiol, sexually differentiate the brain, little is known about the mechanism that actually generates the male-specific neonatal testosterone surge. This review examines the evidence for the role of the hypothalamus, and particularly the gonadotropin-releasing hormone (GnRH) neurons, in generating the neonatal testosterone surge in rodents and primates. Kisspeptin–GPR54 signalling is well established as a potent and critical regulator of GnRH neuron activity during puberty and adulthood, and we argue here for an equally important role at birth in driving the male-specific neonatal testosterone surge in rodents. The presence of a male-specific population of preoptic area kisspeptin neurons that appear transiently in the perinatal period provide one possible source of kisspeptin drive to neonatal GnRH neurons in the mouse.

Nerve and Brain

Mind Shift ◽  
2021 ◽  
pp. 63-79
Author(s):  
John Parrington
Keyword(s):  
Human Brain ◽  
Glial Cells ◽  
Large Scale ◽  
Brain Size ◽  
Adult Brain ◽  
The Other ◽  
Basic Unit ◽  
The Brain ◽  
Size And Structure

This chapter evaluates the basic unit of the human brain: the nerve cell, or neuron. These cells are also the main units of the peripheral nervous system, which sends messages from the brain to the other tissues and organs that make up our bodies. Neurons are the most well-known cells in the brain but they are not the only type of cell in this organ. The other main types are the glial cells, also known as neuroglia. Recent studies of the role of glial cells in the brain are revealing potentially important differences between humans and other species in the functions of these cells. The chapter then turns to the large-scale structure of the brain. The most dramatic changes in brain size and structure occurred in the final phase of human evolutionary change. Indeed, Neanderthals had brains similar in size to those of modern humans. An important feature of the human brain is that a larger fraction of its growth occurs outside the womb. Although humans reach adult brain size in childhood, brain development continues for decades afterwards.

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