Home

Zebrafish brain development

Atlas of Early Zebrafish Brain Development ScienceDirec

  1. Atlas of Early Zebrafish Brain Development: A Tool for Molecular Neurogenetics, Second Edition, remains the only neuroanatomical expression atlas of important genetic and immunohistochemical markers of this vertebrate model system
  2. g a leading vertebrate model for studies of circuit function and behaviour. An essential prerequisite for such studies is an understanding of the neuroanatomy of the brain. In collaboration with Jon Clarke's.
  3. Zebrafish, a popular aquarium fish, can reveal the inner workings of the nervous system, according to exciting research from OHSU Professor Kelly Monk, Ph.D. Dr. Monk will share insights on her team's recent discoveries and how they are opening up opportunities to learn more about brain biology and neurological disease
  4. Anatomy, development, and plasticity of the neurosecretory hypothalamus‎ in zebrafish The paraventricular nucleus (PVN) of the hypothalamus harbors diverse neurosecretory cells with critical physiological roles for the homeostasis
  5. In vivo imaging is a powerful tool that can be used to investigate the cellular mechanisms underlying nervous system development. Here we describe a technique for using time-lapse confocal microscopy to visualize large numbers of multicolor Brainbow-labeled cells in real time within the developing zebrafish nervous system
  6. The zebrafish is a well-established model system used to study and understand various human biological processes. The present study used OCT to investigate growth of the adult zebrafish brain. Twenty..

ZebrafishBrain — Zebrafish UC

The zebrafish has become the standard model for the study of the development of the brain in vertebrates. Molecular biologists, developmental biologists, and neuroscientists increasingly turn to this fish with it's now wide variety of available mutants and known marker genes A role of rbmx in zebrafish brain development is consistent with the suggestion that the human RBMX gene may be involved in neurological disorders that lead to functional and behavioral deficits such as mental retardation syndromes (Graves et al., 2002)

In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis To study adult brain regeneration in zebrafish, we developed a novel stab lesion assay that reproducibly injures the central dorsal telencephalon (DT), i.e. the inner parenchyma, by nasal insertion of a canula along the rostrocaudal body axis . A characteristic of the zebrafish brain is its widespread constitutive life-long neurogenesis pearing in the development of zebrafish, Danio (Brachydanio) rerio, embryos fertilized simultaneously in vitro (C. Walker and G. Streisinger, in Westerfield, 1994) and incubated at an optimal temperature with- out crowding (28.S0C, 5-10 embryos/ml). Asynchrony arises at the earliest stages, and it becomes more pro- nounced as time passes Atlas of Early Zebrafish Brain Development: A Tool for Molecular Neurogenetics, Second Edition, remains the only neuroanatomical expression atlas of important genetic and immunohistochemical markers of this vertebrate model system. It represents a key reference and interpretation matrix for analyzing expression domains of genes involved in Zebrafish brain development and neurogenesis, and.

Atlas of Early Zebrafish Brain Development-Dr. Thomas Mueller 2015-11-18 Atlas of Early Zebrafish Brain Development: A Tool for Molecular Neurogenetics, Second Edition, remains the only neuroanatomical expression atlas of important genetic and immunohistochemical markers of this vertebrate model system Neuroanatomy and circuit development. The developing zebrafish is rapidly becoming a leading vertebrate model for studies of circuit function and behaviour. An essential prerequisite for such studies is an understanding of the neuroanatomy of the brain. In collaboration with Jon Clarke's, lab in KCL, we have been developing an online, high. Hmgb1 (high mobility group box-1; amphoterin) is highly expressed in brain during early development of vertebrate and nonvertebrate species. However, its role in brain development remains elusive. Here we have cloned the zebrafish Hmgb1 and specifically manipulated Hmgb1 expression using injection of morpholino antisense oligonucleotides or Hmgb1 cRNA. . The HMGB1 knockdown morphants produced.

Figure 1. Simple organization of the neural tube of a zebrafish embryo after 24 h of development. A schematized cross-section through a 24 h embryo (left) indicating general architectural features, including the overlying non-neural ectoderm, the roofplate (RP), dorsal-, inter- and motorneurons, the floorplate (FP) and the underlying notochord, is transposed onto a lateral view of a zebrafish. Recent investigations employing zebrafish and other teleost fish continued this work in an evolutionary context, and specifically demonstrated that RA is required for the initiation of tooth development. RA is also sufficient in certain circumstances to induce de novo tooth formation. Both effects appear to involve cranial-neural crest cells. We describe a series of stages for development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad periods of embryogenesis—the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods. These divisions highlight the changing spectrum of major developmental processes that occur during.

Z-Brain Atlas - Z-Brain is a 3D reference atlas, that contains neuroanatomical labels and regional definitions within a standard coordinate space. The Zebrafish Virtual Atlas and The Zebrafish Anatomy Project - The Zebrafish Atlas contains 2- and 3-dimensional, anatomical reference slides of zebrafish to support research and education worldwide. Characterization of the zebrafish lgi1a gene. The main objectives of this study were to determine whether knockdown of lgi1 expression in zebrafish would result in seizure-like behavior and whether embryonic development, particularly of the brain, is affected. As a result of partial duplication within the zebrafish genome during evolution, there are now two copies of many genes, including lgi1 Zebrafish brain aging was evaluated by analyzing signal attenuation rates and texture features in regions of interest (ROIs). Optical scattering originates from light interaction with biological structures. During development, the zebrafish brain gains cells. Signal attenuation rate, therefore, increases with increasing zebrafish brain age. Researchers studying the brain love zebrafish. Their embryos are clear, making them easy to observe, and their brains develop very quickly. What's more, scientists have sequenced the entire zebrafish genome — by knowing which genes do what, scientists can tinker with the genetic blueprint to model a host of neurological conditions from depression to autism spectrum disorders Zebrafish as a model for vertebrate brain ventricle development In some respects, formation of the zebrafish neural tube appears different from that of frog, as in the brain region the zebrafish neural tube is initially straight whereas in the frog Xenopus the presumptive brain undergoes some morphogenesis prior to neural tube closure

Since, the central neuroendocrine systems are responsible for the control of homeostatic processes in the body, including reproduction, growth, metabolism and energy balance, as well as stress responsiveness, the involvement of zebrafish dax1 into brain development might affect sexual differentiation through endocrine systems 4. Early Development of the Zebrafish Circadian System. Among the advantages of the zebrafish model for experimental manipulation are its small size and ease of maintenance in large numbers, its short generation time and high fecundity, its external fertilization, and the rapid development of transparent embryos

Frontiers | Common and Distinct Features of Adult

PHF8 regulates cell survival in the zebrafish brain and jaw development, thus providing a potentially relevant biological context for understanding the clinical symptoms associated with PHF8 patients While notable similarities and differences exist between the embryonic brain development in human and zebrafish, zebrafish nonetheless represents a tractable model for understanding development of vertebrate nervous system and brain disorders such as autism in humans (Tropepe and Sive, 2003). The zebrafish brain has the typical vertebrate. Imaging brain development in immobilized zebrafish embryos and head explants. A,B: As the zebrafish embryo develops from the 15-somite stage (16.5 hours postfertilization [hpf]) to the 24-hr stage, the body axis undergoes substantial straightening. The head region also undergoes changes in its curvature In a screen for embryonic mutants in the zebrafish a large number of mutants were isolated with abnormal brain morphology. We describe here 26 mutants in 13 complementation groups that show abnormal development of large regions of the brain. Early neurogenesis is affected in white tail (wit) Neuroanatomy of the Zebrafish Brain-Mario F. Wulliman 1997-03-14 gene-expression patterns in the zebrafish correspond well The zebrafish belongs to the teleostean family of with the neuromeric model of Puelles and Rubenstein cyprinids (minnows), which includes other neurobiologi (1993) is very encouraging for further research in this call

Zebrafish as a Developmental System

Brain Awareness Lecture: Zebrafish and the Secret to Brain

Zebrafish Development - Embryolog

  1. Similar to mammals, meninges overlay the zebrafish brain (Caruncho et al., 1993).Recent studies in mice revealed the presence of lymphatic vessels in the dura mater, which function in macromolecule clearance (Aspelund et al., 2015; Louveau et al., 2015).To investigate zebrafish as a potential tool for the study of brain lymphatic development and function we analyzed Tg(kdr-l:HRAS-mCherry-CAAX.
  2. e when and how the zebrafish BBB becomes functional in different brain regions, we performed intracardiac injections of fluorescently conjugated tracers (1 kDa NHS and 10 kDa Dex-tran) simultaneously at different developmental stages and imaged live fish after 1 hr of tracer circu
  3. The key role that GLUT2 protein plays in embryonic brain development in zebrafish has now been reported by researchers. A new article proves that this molecule depletion alters the development of.
  4. The findings may form the basis for the development of future treatments using brain stem cells, such as for brain cancer, neurodegenerative diseases like Alzheimer's and Parkinson's, and various.
  5. Pericytes are first visualized in the zebrafish brain at 48 hpf and vSMCs at around 80 hpf. We tested multiple stages of development and chose two stages to study. At 4 dpf, pdgfrb -expressing pericytes have been present for about 2 days, while vSMCs are only starting to express acta2 and are therefore not fully differentiated
  6. It will also involve the analysis of high throughput data produced by RNA-seq and ChIP-seq experiments. The candidate will benefit from the expertise of Paula Alexdandre's Lab in manipulating zebrafish and brain development and David Michod's lab in paediatric brain tumour and epigenetics. References: 1. D
  7. The researchers hope to conduct further studies of how FGPs interact with blood vessels and the blood-brain barrier. The researchers noted that, unlike mammals, embryonic zebrafish can be observed under a microscope as they develop, providing an easy means for studying the role of FGPs in protecting the brain

The results show that cells forming the RG cluster in the adult zebrafish brain mainly correspond to various glial cell types in the murine brain, i.e. astrocytes and radial glia-like neural stem cells (RGLs) of different maturation stages, neurogenic intermediate progenitor cells (nIPCs) with minor proportions corresponding to neuroblasts. Closing Date: 15 March 2021. We are looking for a highly motivated PhD student interested in zebrafish brain development, RNA metabolism, gene editing and transcriptomic analyses to join the Nikolaou Lab at the University of Bath. The deadline for applications is 31st January 2021. The anticipated start date for this project is early October 2021 In zebrafish larvae, functional imaging, mainly by means of calcium imaging, enables one to non-invasively and systematically probe response properties of neurons at a single cell resolution over a wide extent of the brain or even across the entire brain (Ahrens et al., 2012, 2013). Thus, this technological advance, combined with rich genetic.

Rink E, Wullimann MF. Development of the catecholaminergic system in the early zebrafish brain: an immunohistochemical study. Brain Res Dev Brain Res 2002; 137(1):89-100. CrossRef PubMed Google Schola Electroporation is a technique for the introduction of nucleic acids and other macromolecules into cells. In chick embryos it has been a particularly powerful technique for the spatial and temporal control of gene expression in developmental studies. Electroporation methods have also been reported for Xenopus, zebrafish, and mouse. We present a new protocol for zebrafish brain electroporation F-spondin is part of a group of evolutionarily conserved extracellular matrix proteins in vertebrates. It is highly expressed in the embryonic floor plate, and it can bind to the ECM and promote neuronal outgrowth. A characterization of F-spondin expression patterns in the adult zebrafish brain was previously reported by our group. However, given its importance during development, we aimed to.

brain, hexb−/−) zebrafish are viable and apparently resistant to Hexb deficiency. In all, we identified cellular consequences of loss of Hexb enzyme activity during embryonic brain development, showing early effects on glia, which possibly underlie the behavioral aber-rations Antonia Groneberg's innovative depiction of zebrafish brain development has just reeled in Science's annual Dance Your Ph.D. prize. A dancer since she was young, Groneberg taught. Whilst the vascular anatomy of the embryonic fish , the anatomy of the embryonic and adult brain [11, 12], and heart have been elegantly described, there is a need for a detailed record of zebrafish development that spans the entire life history of the organism and presents its anatomy

Knockdown of Zebrafish glut2 Disrupts Brain Development. To study the function of glut2 during the early development in zebrafish, we investigated the effects of abrogation of glut2 by using two different antisense morpholinos, one to inhibit translation at the start methionine (ATG MO) and a second one designed to interfere with splicing. In addition, we have developed software for zebrafish behavioral and neuroanatomical analysis and a library of enhancer trap lines for manipulating the nervous system. Enhancer trap lines with strong expression in the nervous system are included in our Brain Browser, an atlas of zebrafish transgenic lines Hence, studies using zebrafish have the potential to provide fundamental insights about brain development and function, and also elucidate neural and molecular mechanisms of neurological diseases. We will discuss here recent discoveries on the diverse roles of radial glia and astroglia in neurogenesis, in modulating neuronal activity and in. Fengzhu Xiong, Sean Megason (Harvard Medical School)See also http://www.olympusbioscapes.com/gallery/2011/index.htmlThis movie provides a single-cell resolut.. The identified studies used zebrafish to examine the effects of nicotine exposure on early development, addiction, anxiety, and learning. The methods used included green fluorescent protein-labeled proteins to track in vivo nicotine-altered neuron development, nicotine-conditioned place preference, and locomotive sensitization linked with high-throughput molecular and genetic screens and.

BIOL3530: Molecular and Developmental Biology, Vertebrate

The Zebrafish Brain Browser is a tool for 3D visualization of transgene and gene expression patterns in 6 dpf larval zebrafish. At present, the database includes expression patterns for 264 transgenic, enhancer trap or immunostained larvae, each scanned at high resolution and registered to a single reference brain Melatonin has been widely used as a probiotic agent capable of producing strong neurotransmitter secretion regulatory effects, and the microbiota-gut-brain axis-related studies have also highlighted the role of the gut microbiota in neuromodulation. In the present study, a zebrafish neural hyperactivity model was established using caffeine induction to explore the regulatory effects of. Although specific oligosaccharides accumulate in the adult brain, hexb −/−) zebrafish are viable and apparently resistant to Hexb deficiency. In all, we identified cellular consequences of loss of Hexb enzyme activity during embryonic brain development, showing early effects on glia, which possibly underlie the behavioral aberrations

Visualizing the Developing Brain in Living Zebrafish using

Evaluation of zebrafish brain development using optical

Trim69 regulates zebrafish brain development by ap-1

Zebrafish Stem Cells Could Repair Human Blindness - Save

ZFIN Zebrafish Developmental Stage

Z-Brain is an atlas of the larval zebrafish brain. It can be combined with pERK-based neural-activity measurements from freely behaving zebrafish to identify brain regions involved in generating. The Blood Retinal Barrier (BRB) and Blood Brain Barrier (BBB) is established at 3 dpf in zebrafish. To determine the temporal sequence of establishment of the BRB and BBB in zebrafish, we injected two fluorescent dyes into the circulatory system of Tg(flk1:mCherry) [22, 23] embryos at 2 dpf, 2.5 dpf and 3 dpf.The vasculature of flk1:mCherry embryos is labeled with a red fluorescent protein. Chong, M. & Drapeau, P. Interaction between hind brain and spinal networks during the development of locomotion in zebrafish. Dev. Neurobiol. 67 , 933-947 (2007)

ZFIN Embyonic Developmental Stages - ZFIN The Zebrafish

The zebrafish is a well-established vertebrate model for in vivo study of vascular development.18 Its accessible, small and transparent embryo facilitates high resolution in vivo imaging of the brain vasculature.19 In the present study, we used larval zebrafish as a model and found that endogenous H 2 S plays an important role in the brain. These findings demonstrate that adult zebrafish possess a BBB but it is not known when this barrier becomes functional during zebrafish development. Expression of claudin-5 and ZO-1 have been detected in cerebral microvessels of larval zebrafish from as early as 2 and 3 days post-fertilisation (d.p.f.) respectively [ 7 , 9 ] Anatomy of the 24, 48, 72 and 120 hours Zebrafish (. Danio rerio. ) Embryo. This collection of sections through zebrafish embryos at four different stages of development is thought to provide some help to understand how the zebrafish embryo looks inside. Thin section in Araldite were stained with methylene blue FIGURE 2 Immunohistochemistry of Amigo1 expression during early development of the zebrafish brain. A, whole mount immunostaining of Amigo1 in 28-hpf larvae. Anti-Amigo1 antibodies were used as the primary antibodies, and goat anti-chicken Alexa 488 antibodies were used as the secondary antibodies for fluorescent labeling Trim69 was expressed in zebrafish embryos brain at various early developmental stages. Whole mount in situ hybridization was done in order to examine the expression of trim69 in zebrafish embryos during different stages of development. It was found that trim69 was ubiquitously expressed in zebrafish embryos' brain of 24hpf, 48hpf, and 72hpf. And it was restrictedly expressed in the eye.

Zebrabow: multispectral cell labeling for cell tracing and

Frontiers The Effects of Early Life Stress on the Brain

Zebrafish is an attractive model organism to study vertebrate brain development. Its transparency makes it possible to follow development using live imaging. In a transgenic line where a subset of neurons is labeled by GFP expression, their migration, proliferation and the extension of axons can be observed by laser scanning confocal microscopy. Atlas of Early Zebrafish Brain Development: A Tool for Molecular Neurogenetics - Kindle edition by Mueller, Thomas, Dr., Wullimann, Mario. Download it once and read it on your Kindle device, PC, phones or tablets. Use features like bookmarks, note taking and highlighting while reading Atlas of Early Zebrafish Brain Development: A Tool for Molecular Neurogenetics ZFIN is hiring both a software developer and a curator! The Zebrafish Information Network (ZFIN) is the database of genetic and genomic data for the zebrafish (Danio rerio) as a model organism.ZFIN provides a wide array of expertly curated, organized and cross-referenced zebrafish research data

BIOL1020 Genetics blog: Zebrafish : The Current and Future

Imaging a zebrafish's brain at all stages of its developmen

This study was undertaken to ascertain whether defined markers of early zebrafish brain development are affected by chronic ethanol exposure or morpholino knockdown of agrin, sonic hedgehog, retinoic acid, and fibroblast growth factors, four signaling molecules that are suggested to be ethanol sensitive. Zebrafish embryos were exposed to 2% ethanol from 6 to 24 hpf or injected with agrin, shha. The zebrafish has become the standard model for the study of the development of the brain in vertebrates. Molecular biologists, developmental biologists, and neuroscientists increasingly turn to this fish with it's now wide variety of available mutants and known marker genes. This book is intended as a basic handbook and guideline for zebrafish researchers who seek to understand early brain.

Emergence of Neuronal Diversity during Vertebrate Brain

Trim69 was found to be expressed in zebrafish embryo brain at the early stages. Knockdown of trim69 led to deformed brain development, obvious signs of apoptosis present in the head, and decreased expression of neuronal differentiation and stem cell markers The zebrafish brain aminergic systems share many structural properties with the mammalian systems. The noradrenergic, serotonergic, and histaminergic systems are highly similar. The dopaminergic systems also show similarities with the major difference being the lack of dopaminergic neurons in zebrafish mesencephalon To examine whether the apoptosis of ECs contributes to brain vessel pruning, we monitored the development of the brain vasculature in individual larval zebrafish with 1-h interval during 3-3.5 dpf, when most brain vessel pruning events occur (Chen et al., 2012)

Neurogenesis in zebrafish - Neural Developmen

In zebrafish larvae, functional imaging, mainly by means of calcium imaging, enables one to non-invasively and systematically probe response properties of neurons at a single cell resolution over a wide extent of the brain or even across the entire brain (Ahrens et al., 2012, 2013). Thus, this technological advance, combined with rich genetic. Zebrafish exposed to the leading cannabinoids found in cannabis in the earliest stages of development suffer a significant drop in neural activity later in life, according to a new study that has. PHF8 regulates cell survival in the zebrafish brain and jaw development, thus providing a potentially relevant biological context for understanding the clinical symptoms associated with PHF8 patients. Lastly, genetic and molecular evidence supports a model whereby PHF8 regulates zebrafish neuronal cell survival and jaw development in part by.

lockjaw encodes a zebrafish tfap2a required for early

Atlas of Early Zebrafish Brain Development: A Tool for

Hmgb1 (high mobility group box-1; amphoterin) is highly expressed in brain during early development of vertebrate and nonvertebrate species. However, its role in brain development remains elusive. Here we have cloned the zebrafish Hmgb1 and specifically manipulated Hmgb1 expression using injection of morpholino antisense oligonucleotides or Hmgb1 cRNA We study early development using the zebrafish, as well as mouse, cell culture, and cavefish (Astyanax mexicanus) models.. A large component of our efforts are devoted to understanding mechanisms guiding the formation of blood and lymphatic vessels This includes the Plexin-A1 gene. If we switch off this gene in zebrafish, brain development disorders similar to those in humans appear, Dworschak explains. He hopes that the results of the. DEVELOPMENTAL DYNAMICS 221:231-237 (2001) BRIEF COMMUNICATION Zebrafish E-Cadherin: Expression During Early Embryogenesis and Regulation During Brain Development SHERRY G. BABB,1 JESSICA BARNETT,1 ANDREW L. DOEDENS,1 NICOLE COBB,1 QIN LIU,2 BARBARA C. SORKIN,3 PAMELA C. YELICK,3 PAMELA A. RAYMOND,2 AND JAMES A. MARRS1* 1 Department of Medicine, Indiana University Medical Center, Indianapolis. Aberrant brain development with clusters of apoptotic cells and poor brain circulation illustrates brain malfunction in mct8-deficient zebrafish. Hypothyroidism often causes impaired brain development and induces neuropsychomotor defects (5, 9, 36)

Epigenetic regulators Rbbp4 and Hdac1 are overexpressed in

RBMX gene is essential for brain development in zebrafish

The zebrafish, a common laboratory animal used in early drug development, is deemed a good candidate to test toxicity as an alternative to rodents and other mammals The team explains that the development of the zebrafish's nervous systems starts with a brain primordium and a neural tube. These go on to develop and innervate (send nerve bundles) throughout. Zebrafish are a wonderful model for studying hair cell development for a number of reasons. The hair cells are exposed and can be easily seen under the microscope in the live fish Zebrafish are a widely accepted biomedical model for understanding embryonic brain development. About 80 per cent of the genes found in people have a counterpart in zebrafish — and possess very similar developmental processes as humans. Sources and more informatio

Cadmium inhibits neurogenesis in zebrafish embryonic brain

GLUT2 is a glucose transporter that facilitates the entry of glucose―a monosaccharide crucial for proper brain function― inside cells. In order to investigate GLUT2 function in embryonic brain development, the UB group knocked down GLUT2 in zebrafish embryos and examine the anomalies that took place Zebrafish Brain Development AI TAKANO1,3*, RIYO ZOCHI1, MASAHIKO HIBI2, TOSHIO TERASHIMA1, and YU KATSUYAMA1 1 Division of Anatomy and Neurobiology, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan 2 Laboratory for Vertabrate Body Axis, RIKEN Center for Developmental Biology

Defective adgra2 (gpr124) splicing and function in

Regeneration of the adult zebrafish brain from neurogenic

in the brain ventricles of zebrafish embryos. App in ependymal cilia persisted in adult zebrafish 31. and was also detected in mouse and human brain. Finally, we found morphologically abnormal 32 ependymal cilia and smaller brain ventricles in . appa-/ appb-/ mutant zebrafish. Our findings 3 Here we demonstrate that bisphenol A (BPA) exposure during a time point analogous to the second trimester in humans has real and measurable effects on brain development and behavior. Furthermore, our study is the first, to our knowledge, to show that bisphenol S, a replacement used in BPA-free products, equally affects neurodevelopment. These findings suggest that BPA-free products are not. Qi HH, Sarkissian M, Hu GQ, Wang Z, Bhattacharjee A, Gordon DB et al. Histone H4K20/H3K9 demethylase PHF8 regulates zebrafish brain and craniofacial development. Nature . 2010 Jul 23;466(7305):503-507 Hexb enzyme deficiency leads to lysosomal abnormalities in radial glia and microglia in zebrafish brain development Laura E. Kuil , 1 Anna López Martí , 1 , † Ana Carreras Mascaro , 1 , † Jeroen C. van den Bosch , 1 Paul van den Berg , 1 Herma C. van der Linde , 1 Kees Schoonderwoerd , 1 George J. G. Ruijter , 1 and Tjakko J. van Ham Objectives. Neuronal development and function is dependent on the interaction between the central nervous system and immune system. Microglia are resident macrophages of the brain critical for regulating neuronal activity during embryonic development. 5-methyltetrahydrofolate (5MTHF), the bioactive folate form, is essential for fetal brain development and immune function