Forebrain Architecture and Development in Cyclostomes, with Reference to the Early Morphology and Evolution of the Vertebrate Head

2021 ◽  
pp. 1-13
Author(s):  
Fumiaki Sugahara ◽  
Yasunori Murakami ◽  
Juan Pascual-Anaya ◽  
Shigeru Kuratani
Keyword(s):  
Brain Development ◽  
Brain Evolution ◽  
Ct Scanning ◽  
Craniofacial Morphology ◽  
Last Common Ancestor ◽  
Developmental Studies ◽  
Developmental Mechanism ◽  
Anterior Division ◽  
Head Morphology ◽  
The Brain

The vertebrate head and brain are characterized by highly complex morphological patterns. The forebrain, the most anterior division of the brain, is subdivided into the diencephalon, hypothalamus, and telencephalon from the neuromeric subdivision into prosomeres. Importantly, the telencephalon contains the cerebral cortex, which plays a key role in higher order cognitive functions in humans. To elucidate the evolution of the forebrain regionalization, comparative analyses of the brain development between extant jawed and jawless vertebrates are crucial. Cyclostomes – lampreys and hagfishes – are the only extant jawless vertebrates, and diverged from jawed vertebrates (gnathostomes) over 500 million years ago. Previous developmental studies on the cyclostome brain were conducted mainly in lampreys because hagfish embryos were rarely available. Although still scarce, the recent availability of hagfish embryos has propelled comparative studies of brain development and gene expression. By integrating findings with those of cyclostomes and fossil jawless vertebrates, we can depict the morphology, developmental mechanism, and even the evolutionary path of the brain of the last common ancestor of vertebrates. In this review, we summarize the development of the forebrain in cyclostomes and suggest what evolutionary changes each cyclostome lineage underwent during brain evolution. In addition, together with recent advances in the head morphology in fossil vertebrates revealed by CT scanning technology, we discuss how the evolution of craniofacial morphology and the changes of the developmental mechanism of the forebrain towards crown gnathostomes are causally related.

Inductive patterning of the embryonic brain in Drosophila

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2121-2128
Author(s):  
Damon T. Page
Keyword(s):  
Brain Development ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Embryonic Brain ◽  
Germ Layers ◽  
Brain Anomaly ◽  
Prechordal Plate ◽  
Foregut Endoderm ◽  
The Brain ◽  
Brain Patterning

In vertebrates (deuterostomes), brain patterning depends on signals from adjacent tissues. For example, holoprosencephaly, the most common brain anomaly in humans, results from defects in signaling between the embryonic prechordal plate (consisting of the dorsal foregut endoderm and mesoderm) and the brain. I have examined whether a similar mechanism of brain development occurs in the protostome Drosophila, and find that the foregut and mesoderm act to pattern the fly embryonic brain. When the foregut and mesoderm of Drosophila are ablated, brain patterning is disrupted. The loss of Hedgehog expressed in the foregut appears to mediate this effect, as it does in vertebrates. One mechanism whereby these defects occur is a disruption of normal apoptosis in the brain. These data argue that the last common ancestor of protostomes and deuterostomes had a prototype of the brains present in modern animals, and also suggest that the foregut and mesoderm contributed to the patterning of this ‘proto-brain’. They also argue that the foreguts of protostomes and deuterostomes, which have traditionally been assigned to different germ layers, are actually homologous.

scholarly journals SIRT6 Through the Brain Evolution, Development, and Aging

2021 ◽  
Vol 13 ◽  
Author(s):  
Alfredo Garcia-Venzor ◽  
Debra Toiber
Keyword(s):  
Embryonic Development ◽  
Neurodegenerative Diseases ◽  
Brain Development ◽  
Aging Process ◽  
Brain Aging ◽  
Brain Evolution ◽  
Loss Of Function ◽  
Brain Health ◽  
Development And Aging ◽  
The Brain

During an organism’s lifespan, two main phenomena are critical for the organism’s survival. These are (1) a proper embryonic development, which permits the new organism to function with high fitness, grow and reproduce, and (2) the aging process, which will progressively undermine its competence and fitness for survival, leading to its death. Interestingly these processes present various similarities at the molecular level. Notably, as organisms became more complex, regulation of these processes became coordinated by the brain, and failure in brain activity is detrimental in both development and aging. One of the critical processes regulating brain health is the capacity to keep its genomic integrity and epigenetic regulation—deficiency in DNA repair results in neurodevelopmental and neurodegenerative diseases. As the brain becomes more complex, this effect becomes more evident. In this perspective, we will analyze how the brain evolved and became critical for human survival and the role Sirt6 plays in brain health. Sirt6 belongs to the Sirtuin family of histone deacetylases that control several cellular processes; among them, Sirt6 has been associated with the proper embryonic development and is associated with the aging process. In humans, Sirt6 has a pivotal role during brain aging, and its loss of function is correlated with the appearance of neurodegenerative diseases such as Alzheimer’s disease. However, Sirt6 roles during brain development and aging, especially the last one, are not observed in all species. It appears that during the brain organ evolution, Sirt6 has gained more relevance as the brain becomes bigger and more complex, observing the most detrimental effect in the brains of Homo sapiens. In this perspective, we part from the evolution of the brain in metazoans, the biological similarities between brain development and aging, and the relevant functions of Sirt6 in these similar phenomena to conclude with the evidence suggesting a more relevant role of Sirt6 gained in the brain evolution.

Bone-brain crosstalk and potential associated diseases

2016 ◽  
Vol 28 (2) ◽  
Author(s):  
Audrey Rousseaud ◽  
Stephanie Moriceau ◽  
Mariana Ramos-Brossier ◽  
Franck Oury
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Development ◽  
Cognitive Functions ◽  
Intimate Relationship ◽  
Whole Body ◽  
Reciprocal Relationships ◽  
Skeletal Homeostasis ◽  
The Central Nervous System ◽  
The Brain

AbstractReciprocal relationships between organs are essential to maintain whole body homeostasis. An exciting interplay between two apparently unrelated organs, the bone and the brain, has emerged recently. Indeed, it is now well established that the brain is a powerful regulator of skeletal homeostasis via a complex network of numerous players and pathways. In turn, bone via a bone-derived molecule, osteocalcin, appears as an important factor influencing the central nervous system by regulating brain development and several cognitive functions. In this paper we will discuss this complex and intimate relationship, as well as several pathologic conditions that may reinforce their potential interdependence.

Neurodevelopment in the first three years: implications for child development, professional practice and policy

2014 ◽  
Vol 9 (2) ◽  
pp. 154-164 ◽  
Author(s):  
Danya Glaser
Keyword(s):  
Brain Development ◽  
Brain Activity ◽  
Brain Maturation ◽  
Policy And Practice ◽  
Content Type ◽  
Key Issues ◽  
And Function ◽  
The Relationship ◽  
The Brain ◽  
Brain Connections

Purpose – The purpose of this paper is to outline brain structure and development, the relationship between environment and brain development and implications for practice. Design/methodology/approach – The paper is based on a selected review of the literature and clinical experience. Findings – While genetics determine the sequence of brain maturation, the nature of brain development and functioning is determined by the young child's caregiving environment, to which the developing brain constantly adapts. The absence of input during sensitive periods may lead to later reduced functioning. There is an undoubted immediate equivalence between every mind function – emotion, cognition, behaviour and brain activity, although the precise location of this in the brain is only very partially determinable, since brain connections and function are extremely complex. Originality/value – This paper provides an overview of key issues in neurodevelopment relating to the development of young children, and implications for policy and practice.

scholarly journals Retrotransposon-induced mosaicism in the neural genome

Open Biology ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 180074 ◽  
Author(s):  
Gabriela O. Bodea ◽  
Eleanor G. Z. McKelvey ◽  
Geoffrey J. Faulkner
Keyword(s):  
Brain Development ◽  
Adult Neurogenesis ◽  
Neurological Disease ◽  
Dynamic Structure ◽  
Neurological Function ◽  
Developing Brain ◽  
Neural Cells ◽  
The Past ◽  
Retrotransposon Activity ◽  
The Brain

Over the past decade, major discoveries in retrotransposon biology have depicted the neural genome as a dynamic structure during life. In particular, the retrotransposon LINE-1 (L1) has been shown to be transcribed and mobilized in the brain. Retrotransposition in the developing brain, as well as during adult neurogenesis, provides a milieu in which neural diversity can arise. Dysregulation of retrotransposon activity may also contribute to neurological disease. Here, we review recent reports of retrotransposon activity in the brain, and discuss the temporal nature of retrotransposition and its regulation in neural cells in response to stimuli. We also put forward hypotheses regarding the significance of retrotransposons for brain development and neurological function, and consider the potential implications of this phenomenon for neuropsychiatric and neurodegenerative conditions.

scholarly journals Evolution in the Brain, Evolution in the Mind: The Hierarchical Brain and the Interface between Psychoanalysis and Neuroscience

2017 ◽  
Vol 19 (3) ◽  
pp. 349-377
Author(s):  
Leonardo Niro Nascimento
Keyword(s):  
Brain Evolution ◽  
The Other ◽  
Common Source ◽  
Evolutionary Models ◽  
Anatomy And Physiology ◽  
Psychodynamically Oriented ◽  
The One ◽  
The Mind ◽  
The Brain ◽  
Shed Light

This article first aims to demonstrate the different ways the work of the English neurologist John Hughlings Jackson influenced Freud. It argues that these can be summarized in six points. It is further argued that the framework proposed by Jackson continued to be pursued by twentieth-century neuroscientists such as Papez, MacLean and Panksepp in terms of tripartite hierarchical evolutionary models. Finally, the account presented here aims to shed light on the analogies encountered by psychodynamically oriented neuroscientists, between contemporary accounts of the anatomy and physiology of the nervous system on the one hand, and Freudian models of the mind on the other. These parallels, I will suggest, are not coincidental. They have a historical underpinning, as both accounts most likely originate from a common source: John Hughlings Jackson's tripartite evolutionary hierarchical view of the brain.

scholarly journals Evolutionary modifications in human brain connectivity associated with schizophrenia

Brain ◽  
2019 ◽  
Vol 142 (12) ◽  
pp. 3991-4002 ◽  
Author(s):  
Martijn P van den Heuvel ◽  
Lianne H Scholtens ◽  
Siemon C de Lange ◽  
Rory Pijnenburg ◽  
Wiepke Cahn ◽  
...  
Keyword(s):  
Human Brain ◽  
Brain Connectivity ◽  
Brain Evolution ◽  
Higher Order ◽  
Brain Functions ◽  
Human Brain Evolution ◽  
The Brain

See Vértes and Seidlitz (doi:10.1093/brain/awz353) for a scientific commentary on this article. Is schizophrenia a by-product of human brain evolution? By comparing the human and chimpanzee connectomes, van den Heuvel et al. demonstrate that connections unique to the human brain show greater involvement in schizophrenia pathology. Modifications in service of higher-order brain functions may have rendered the brain more vulnerable to dysfunction.

scholarly journals Cerebral Cavernous Hemangioma in a Dog

2019 ◽  
Vol 47 ◽  
Author(s):  
Viviane Motta dos Santos Moretto ◽  
Luciana Maria Curtio Soares ◽  
Esthefanie Nunes ◽  
Uiara Hanna Araújo Barreto ◽  
Valéria Régia Franco Sousa ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Endothelial Cells ◽  
Cavernous Hemangioma ◽  
Clinical Signs ◽  
Ct Scanning ◽  
Ct Scans ◽  
Elastic Fibers ◽  
Post Contrast ◽  
The Right ◽  
The Brain

Background: Cerebral cavernous hemangioma is a rare neoplasm of vascular origin in the brain, characterized by abnormally dilated vascular channels surrounded by endothelium without muscle or elastic fibers. Presumptive diagnosis is performed by magnetic resonance or computed tomography (CT) scanning and can be confirmed by histopathology. The prognosis of intracranial cavernous hemangioma is poor, with progression of clinical signs culminating in spontaneous death or euthanasia. The purpose of this paper is to report a case of cerebral cavernous hemangioma in a dog, presenting the clinical findings, tomographic changes, and pathological findings.Case: This case involved a 2-year-old medium sized mixed breed female dog presenting with apathy, hyporexia, ataxia, bradycardia, dyspnea, and seizure episodes for three days. Hemogram and serum biochemistry of renal and hepatic function and urinalysis did not reveal any visible changes. CT scanning was also performed. The scans revealed a hyperdense nodule of 15.9 x 14 mm, with well defined borders, and a hypodense halo without post-contrast enhancement and mass effect in the right parietal lobe was observed in both transverse and coronal sections. Based on the image presented in the CT scans, the nodule was defined as a hemorrhagic brain lesion. The animal died after a seizure. The right telencephalon was subjected to necropsy, which revealed a reddish-black wel-defined nodule 1.7 cm in diameter extending from the height of the piriform lobe to the olfactory trine at the groove level and extending towards the lateral ventricle, with slight compression and deformation of the thalamus but no other macroscopic alterations in the other organs. The histopathology indicated that this nodular area in the encephalus contained moderate, well-delimited but unencapsulated cellularity, composed of large vascular spaces paved with endothelial cells filled with erythrocytes, some containing eosinophilic fibrillar material (fibrin) and others with organized thrombus containing occasional neutrophil aggregates. The endothelial cells had cytoplasm with indistinct borders, elongated nuclei, scanty crust-like chromatin, and cellular pleomorphism ranging from discrete to moderate, without mitotic figures.Discussion: The histological findings characterized the morphological changes in the brain as cavernous hemangioma, and the growth and compression of this neoplasm were considered the cause of the clinical signs of this dog. The main complaint was seizures, although ataxia and lethargy were also noted. These clinical signs are often related to changes in the anterior brain and brainstem. The literature does not list computed tomography as a complementary diagnostic method in cases of cerebral cavernous hemangioma in dogs, but CT scanning was useful in confirming cerebral hemorrhage. The main differential diagnosis for cerebral cavernous hemangioma would be a hamartoma, but what differentiates them histologically is the presence of normal interstices between the blood vessels, since no intervening neural tissue occurs in the case of cerebral hemangioma. Therefore, even in the absence of immunohistochemistry to more confidently confirm a cavernous hemangioma, the clinical signs, CT scans and especially the pathological findings were consistent with a case of cerebral cavernous hemangioma, a benign neoplasm with a poor prognosis due to the severe neurological changes it causes and its difficult treatment.

scholarly journals Generation of Vascularized Brain Organoids to Study Neurovascular Interactions

2022 ◽  
Author(s):  
Zhen-Ge Luo ◽  
Xin-Yao Sun ◽  
Xiang-Chun Ju ◽  
Yang Li ◽  
Peng-Ming Zeng ◽  
...  
Keyword(s):  
Brain Development ◽  
Neural Development ◽  
Immune Cells ◽  
Aging Process ◽  
Neural Progenitors ◽  
Brain Disorders ◽  
Specific Population ◽  
Neurovascular Interactions ◽  
The Brain

The recently developed brain organoids have been used to recapitulate the processes of brain development and related diseases. However, the lack of vasculatures, which regulate neurogenesis, brain disorders, and aging process, limits the utility of brain organoids. In this study, we induced vessel and brain organoids respectively, and then fused two types of organoids together to obtain vascularized brain organoids. The fused brain organoids were engrafted with robust vascular network-like structures, and exhibited increased number of neural progenitors, in line with the possibility that vessels regulate neural development. Fusion organoids also contained functional blood-brain-barrier (BBB)-like structures, as well as microglial cells, a specific population of immune cells in the brain. The incorporated microglia responded actively to immune stimuli to the fused brain organoids. Thus, the fusion organoids established in this study allow modeling interactions between the neuronal and non-neuronal components in vitro, in particular the vasculature and microglia niche.

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