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1.
Curr Opin Neurol ; 35(5): 660-671, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36069419

RESUMO

PURPOSE OF REVIEW: Intracellular inclusions consisting of the abnormal TDP-43 protein and its nucleocytoplasmic mislocalization in selected cell types are hallmark pathological features of sALS. Descriptive (histological, morphological), anatomical, and molecular studies all have improved our understanding of the neuropathology of sporadic amyotrophic lateral sclerosis (sALS). This review highlights some of the latest developments in the field. RECENT FINDINGS: Increasing evidence exists from experimental models for the prion-like nature of abnormal TDP-43, including a strain-effect, and with the help of neuroimaging-based studies, for spreading of disease along corticofugal connectivities in sALS. Progress has also been made with respect to finding and establishing reliable biomarkers (neurofilament levels, diffusor tensor imaging). SUMMARY: The latest findings may help to elucidate the preclinical phase of sALS and to define possible mechanisms for delaying or halting disease development and progression.


Assuntos
Esclerose Amiotrófica Lateral , Esclerose Amiotrófica Lateral/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Corpos de Inclusão/metabolismo , Corpos de Inclusão/patologia , Neuroanatomia
3.
Oper Neurosurg (Hagerstown) ; 23(4): 279-286, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36103318

RESUMO

BACKGROUND: The complexity of the relationships among the structures within the brain makes efficient mastery of neuroanatomy difficult for medical students and neurosurgical residents. Therefore, there is a need to provide real-time segmentation of neuroanatomic images taken from various perspectives to assist with training. OBJECTIVE: To develop the initial foundation of a neuroanatomic image segmentation algorithm using artificial intelligence for education. METHODS: A pyramidal scene-parsing network with a convolutional residual neural network backbone was assessed for its ability to accurately segment neuroanatomy images. A data set of 879 images derived from The Neurosurgical Atlas was used to train, validate, and test the network. Quantitative assessment of the segmentation was performed using pixel accuracy, intersection-over-union, the Dice similarity coefficient, precision, recall, and the boundary F1 score. RESULTS: The network was trained, and performance was assessed class wise. Compared with the ground truth annotations, the ensembled results for our artificial intelligence framework for the pyramidal scene-parsing network during testing generated a total pixel accuracy of 91.8%. CONCLUSION: Using the presented methods, we show that a convolutional neural network can accurately segment gross neuroanatomy images, which represents an initial foundation in artificial intelligence gross neuroanatomy that will aid future neurosurgical training. These results also suggest that our network is sufficiently robust, to an unprecedented level, for performing anatomic category recognition in a clinical setting.


Assuntos
Inteligência Artificial , Neuroanatomia , Algoritmos , Humanos , Aprendizado de Máquina , Redes Neurais de Computação
4.
J Anat ; 241(4): 981-1013, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36037801

RESUMO

Although our knowledge on crocodylomorph palaeoneurology has experienced considerable growth in recent years, the neuroanatomy of many crocodylomorph taxa has yet to be studied. This is true for Australian taxa, where thus far only two crocodylian crocodylomorphs have had aspects of their neuroanatomy explored. Here, the neuroanatomy of the Australian mekosuchine crocodylian Trilophosuchus rackhami is described for the first time, which significantly increases our understanding on the palaeoneurology of Australian crocodylians. The palaeoneurological description is based on the taxon's holotype specimen (QMF16856), which was subjected to a µCT scan. Because of the exceptional preservation of QMF16856, most neuroanatomical elements could be digitally reconstructed and described in detail. Therefore, the palaeoneurological assessment presented here is hitherto the most in-depth study of this kind for an extinct Australian crocodylomorph. Trilophosuchus rackhami has a brain endocast with a distinctive morphology that is characterized by an acute dural peak over the hindbrain region. While the overall morphology of the brain endocast is unique to T. rackhami, it does share certain similarities with the notosuchian crocodyliforms Araripesuchus wegeneri and Sebecus icaeorhinus. The endosseous labyrinth displays a morphology that is typical for crocodylians, although a stand-out feature is the unusually tall common crus. Indeed, the common crus of T. rackhami has one of the greatest height ratios among crocodylomorphs with currently known endosseous labyrinths. The paratympanic pneumatic system of T. rackhami is greatly developed and most similar to those of the extant crocodylians Osteolaemus tetraspis and Paleosuchus palpebrosus. The observations on the neuroanatomy of T. rackhami are also discussed in the context of Crocodylomorpha. The comparative palaeoneurology reinforces previous evaluations that the neuroanatomy of crocodylomorphs is complex and diverse among species, and T. rackhami has a peculiar neuromorphology, particularly among eusuchian crocodyliforms.


Assuntos
Jacarés e Crocodilos , Fósseis , Jacarés e Crocodilos/anatomia & histologia , Animais , Austrália , Evolução Biológica , Neuroanatomia , Crânio/anatomia & histologia
5.
Curr Biol ; 32(15): 3302-3316.e2, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35809569

RESUMO

In addition to being among the most iconic and bizarre-looking Cambrian animals, radiodonts are a group that offers key insight into the acquisition of the arthropod body plan by virtue of their phylogenetic divergence prior to all living members of the phylum. Nonetheless, radiodont fossils are rare and often fragmentary, and contentions over their interpretation have hindered resolution of important evolutionary conundrums. Here, we describe 268 specimens of Stanleycaris hirpex from the Cambrian Burgess Shale, including many exceptionally preserved whole-body specimens, informing the most complete reconstruction of a radiodont to date. The trunk region of Stanleycaris has up to 17 segments plus two pairs of filiform caudal blades. The recognition of dorsal sclerotic segmentation of the trunk cuticle and putative unganglionated nerve cords provides new insight into the relative timing of acquisition of segmental traits, the epitome of the arthropod body plan. In addition to the pair of stalked lateral eyes, the short head unexpectedly bears a large median eye situated behind a preocular sclerite on an anteriorly projecting head lobe. Upon re-evaluation, similar median eyes can be identified in other Cambrian panarthropods demonstrating a deep evolutionary continuity. The exquisitely preserved brain of Stanleycaris is consistent with the hypothesized deutocerebral innervation of the frontal appendages, reconciling neuroanatomical evidence with external morphology in support of an ancestrally bipartite head and brain for arthropods. We propose that the integration of this bipartite head prior to the acquisition of most segmental characters exclusively in the arthropod trunk may help explain its developmental differentiation.


Assuntos
Artrópodes , Animais , Artrópodes/anatomia & histologia , Evolução Biológica , Fósseis , Neuroanatomia , Filogenia
6.
Proc Natl Acad Sci U S A ; 119(28): e2118295119, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35787056

RESUMO

The biological foundation for the language-ready brain in the human lineage remains a debated subject. In humans, the arcuate fasciculus (AF) white matter and the posterior portions of the middle temporal gyrus are crucial for language. Compared with other primates, the human AF has been shown to dramatically extend into the posterior temporal lobe, which forms the basis of a number of models of the structural connectivity basis of language. Recent advances in both language research and comparative neuroimaging invite a reassessment of the anatomical differences in language streams between humans and our closest relatives. Here, we show that posterior temporal connectivity via the AF in humans compared with chimpanzees is expanded in terms of its connectivity not just to the ventral frontal cortex but also to the parietal cortex. At the same time, posterior temporal regions connect more strongly to the ventral white matter in chimpanzees as opposed to humans. This pattern is present in both brain hemispheres. Additionally, we show that the anterior temporal lobe harbors a combination of connections present in both species through the inferior fronto-occipital fascicle and human-unique expansions through the uncinate and middle and inferior longitudinal fascicles. These findings elucidate structural changes that are unique to humans and may underlie the anatomical foundations for full-fledged language capacity.


Assuntos
Substância Branca , Animais , Mapeamento Encefálico/métodos , Humanos , Idioma , Vias Neurais/anatomia & histologia , Neuroanatomia , Pan troglodytes/anatomia & histologia , Lobo Temporal/anatomia & histologia , Lobo Temporal/diagnóstico por imagem , Substância Branca/anatomia & histologia , Substância Branca/diagnóstico por imagem
7.
PLoS One ; 17(7): e0269773, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35797364

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that can cause significant social, communication, and behavioral challenges. Diagnosis of ASD is complicated and there is an urgent need to identify ASD-associated biomarkers and features to help automate diagnostics and develop predictive ASD models. The present study adopts a novel evolutionary algorithm, the conjunctive clause evolutionary algorithm (CCEA), to select features most significant for distinguishing individuals with and without ASD, and is able to accommodate datasets having a small number of samples with a large number of feature measurements. The dataset is unique and comprises both behavioral and neuroimaging measurements from a total of 28 children from 7 to 14 years old. Potential biomarker candidates identified include brain volume, area, cortical thickness, and mean curvature in specific regions around the cingulate cortex, frontal cortex, and temporal-parietal junction, as well as behavioral features associated with theory of mind. A separate machine learning classifier (i.e., k-nearest neighbors algorithm) was used to validate the CCEA feature selection and for ASD prediction. Study findings demonstrate how machine learning tools might help move the needle on improving diagnostic and predictive models of ASD.


Assuntos
Transtorno do Espectro Autista , Adolescente , Algoritmos , Transtorno do Espectro Autista/diagnóstico por imagem , Biomarcadores , Criança , Humanos , Aprendizado de Máquina , Imageamento por Ressonância Magnética/métodos , Neuroanatomia , Neuroimagem
8.
Curr Protoc ; 2(7): e509, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35857886

RESUMO

Congenital neurodevelopmental anomalies are present from birth and are characterized by an abnormal development of one or more structures of the brain. Brain structural anomalies are highly comorbid with neurodevelopmental and neuropsychiatric disorders such as intellectual disability, autism spectrum disorders, epilepsy, and schizophrenia, and 80% are of genetic origin. We aim to address an important neurobiological question: How many genes regulate the normal anatomy of the brain during development. To do so, we developed a quantitative approach for the assessment of a total of 106 neuroanatomical parameters in mouse mutant embryos at embryonic day 18.5 across two planes commonly used in brain anatomical studies, the coronal and sagittal planes. In this article we describe the techniques we developed and explain why ultrastandardized procedures involving embryonic mouse brains are even more of prime importance for morphological phenotyping than adult mouse brains. We focus our analysis on brain size anomalies and on the most frequently altered brain regions including the cortex, corpus callosum, hippocampus, ventricles, caudate putamen, and cerebellum. Our protocols allow a standardized histology pipeline from embryonic mouse brain preparation to sectioning, staining, and scanning and neuroanatomical analyses at well-defined positions on the coronal and sagittal planes. Together, our protocols will help scientists in deciphering congenital neurodevelopmental anomalies and anatomical changes between groups of mouse embryos in health and genetic diseases. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Fixation and preparation of embryonic mouse brain samples Basic Protocol 2: Sectioning, staining, and scanning of embryonic mouse brain sections Basic Protocol 3: Coronal neuroanatomical measurements of embryonic mouse brain structures Basic Protocol 4: Sagittal neuroanatomical measurements of embryonic mouse brain structures.


Assuntos
Encefalopatias , Neuroanatomia , Animais , Encéfalo/anormalidades , Cerebelo , Técnicas Histológicas/métodos , Camundongos , Neuroanatomia/métodos
9.
Curr Eye Res ; 47(10): 1374-1380, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35904450

RESUMO

PURPOSE: To provide a complete nerve architecture and main sensory neuropeptide distribution in the chicken cornea. METHODS: Adult chickens aged 6 months and 4 years were used. The whole cornea was stained with protein gene product (PGP) 9.5 antibody-a pan marker for nerve fibers, calcitonin gene-related peptide (CGRP), and substance P (SP) antibodies; whole-mount images were acquired to build an entire view of corneal innervation. Relative corneal epithelial nerve fiber densities, including subbasal bundles and superficial terminals, were assessed by computer-assisted analysis. RESULTS: An average of about 76.3 ± 5.7 (n = 8 corneas, 4 M/4F) stromal nerve trunks enter the cornea radially and are evenly distributed around the limbus with no significant difference between male and female chickens. The subbasal nerve bundles do not extend in a given direction and, as a result, do not form a vortex in the center of the cornea. Furthermore, the chicken cornea contains more SP-positive nerves than CGRP-positive nerves. It is also shown that aging significantly reduces corneal epithelial nerve density in chickens. CONCLUSIONS: This is the first study to provide a complete map of the entire corneal nerves and CGRP and SP sensory neuropeptide distribution in the adult chicken cornea. The findings show chicken corneal innervation has many differences to human and mammal cornea.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Neuropeptídeos , Adulto , Envelhecimento/fisiologia , Animais , Galinhas , Córnea/metabolismo , Feminino , Humanos , Masculino , Mamíferos/metabolismo , Neuroanatomia , Neuropeptídeos/metabolismo , Substância P
10.
Rev Colomb Psiquiatr (Engl Ed) ; 51(2): 133-145, 2022.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35717384

RESUMO

INTRODUCTION: Lithium treatment of bipolar disorder (BD) has been associated with less cognitive impairment and fewer changes in structural brain anatomy compared to other treatments. However, the studies are heterogeneous and few assess whether these effects are related. The objective of this study was to evaluate and relate cognitive performance and structural neuroanatomy in patients treated with and without lithium. METHODS: Cross-sectional study that included 48 subjects with BD-I, of which 22 were treated with lithium and 26 without lithium. Performance was assessed on Wechsler III (WAIS III), TMT A and B (Trial Making Test) neuropsychological tests, California verbal learning test (CVLT), Rey complex figure test and Wisconsin card sorting test. Brain structures obtained by magnetic resonance imaging (MRI) were evaluated. The standardised mean difference (SMD) between both groups was calculated, adjusted for confounding variables using a propensity score, and the Spearman correlation coefficient (ρ) was used to assess the relationship between cognitive performance and neuroanatomical regions. RESULTS: Compared to the group without lithium, the group with lithium had fewer perseverative errors in the Wisconsin test (SMD = -0.69) and greater left and right cortical areas (SMD = 0.85; SMD = 0.92); greater surface area in the left anterior cingulate (SMD = 1.32), right medial orbitofrontal cortex (SMD = 1.17), right superior frontal gyrus (SMD = 0.82), and right and left precentral gyrus (SMD = 1.33; SMD = 0.98); greater volume of the right amygdala (SMD = 0.57), right hippocampus (SMD = 0.66), right putamen (SMD = 0.87) and right thalamus (SMD = .67). In the lithium group, a correlation was found with these errors and the thickness of the left precentral gyrus (ρ = -0.78), the volume of the right thalamus (ρ = -0.44), and the right amygdala (ρ = 0.6). CONCLUSIONS: The lithium group had better cognitive flexibility and greater dimension in some frontal and subcortical cortical regions. Furthermore, there was a moderate to high correlation between performance in this executive function and the thickness of the right precentral gyrus, and the volumes of the thalamus and the right amygdala. These findings could suggest a neuroprotective effect of lithium.


Assuntos
Transtorno Bipolar , Transtorno Bipolar/tratamento farmacológico , Cognição , Estudos Transversais , Humanos , Lítio/uso terapêutico , Transtornos do Humor , Neuroanatomia
11.
Hum Brain Mapp ; 43(14): 4492-4507, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35678552

RESUMO

Individual neuroanatomy can influence motor responses to transcranial magnetic stimulation (TMS) and corticomotor excitability after intermittent theta burst stimulation (iTBS). The purpose of this study was to examine the relationship between individual neuroanatomy and both TMS response measured using resting motor threshold (RMT) and iTBS measured using motor evoked potentials (MEPs) targeting the biceps brachii and first dorsal interosseus (FDI). Ten nonimpaired individuals completed sham-controlled iTBS sessions and underwent MRI, from which anatomically accurate head models were generated. Neuroanatomical parameters established through fiber tractography were fiber tract surface area (FTSA), tract fiber count (TFC), and brain scalp distance (BSD) at the point of stimulation. Cortical magnetic field induced electric field strength (EFS) was obtained using finite element simulations. A linear mixed effects model was used to assess effects of these parameters on RMT and iTBS (post-iTBS MEPs). FDI RMT was dependent on interactions between EFS and both FTSA and TFC. Biceps RMT was dependent on interactions between EFS and and both FTSA and BSD. There was no groupwide effect of iTBS on the FDI but individual changes in corticomotor excitability scaled with RMT, EFS, BSD, and FTSA. iTBS targeting the biceps was facilitatory, and dependent on FTSA and TFC. MRI-based measures of neuroanatomy highlight how individual anatomy affects motor system responses to different TMS paradigms and may be useful for selecting appropriate motor targets when designing TMS based therapies.


Assuntos
Córtex Motor , Estimulação Magnética Transcraniana , Potencial Evocado Motor/fisiologia , Humanos , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Neuroanatomia , Plasticidade Neuronal/fisiologia , Ritmo Teta/fisiologia
12.
Scott Med J ; 67(3): 80-86, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35695250

RESUMO

BACKGROUND: A recent trend in medical education is developing a more dynamic and integrated curriculum. Team-based learning (TBL) increases students' engagement and the active construction of anatomical knowledge. This initial study aimed to empirically observe medical students' perceptions of their achievement of learning outcomes and the construction of their neuroanatomy knowledge, critical thinking, and problem-solving using an interactive whiteboard (IWB) as a teaching strategy. METHODS: An independent neuroanatomy lab survey collected students' perceptions and comments about their learning experiences using the IWB on a questionnaire using a 5-point Likert scale. RESULTS: Student participants felt that using the IWB has facilitated their learning experience. 94.2% of student participants endorsed feelings that new technology has helped them achieve their learning outcomes, helped them integrate both their basic science and clinical science/skills knowledge (90.4%), enhanced their problem-solving skills (92.3%), facilitated their interaction with the neuroanatomy faculty (96.2%) and increase their critical thinking (88.4%). CONCLUSION: Collecting such empirical data about students' perceptions and their learning environment should help neurosciences faculty in medical schools better outline their activities to faculty at other medical institutions. Applying these methods may enhance the learning process, save time during neuroanatomy lab, and it could also help overcome the shortage of qualified neuroanatomy educators.


Assuntos
Educação Médica , Estudantes de Medicina , Currículo , Educação Médica/métodos , Humanos , Neuroanatomia , Aprendizagem Baseada em Problemas/métodos
13.
Science ; 376(6597): 1070-1074, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35653486

RESUMO

Autism spectrum disorder (ASD) is highly heterogeneous. Identifying systematic individual differences in neuroanatomy could inform diagnosis and personalized interventions. The challenge is that these differences are entangled with variation because of other causes: individual differences unrelated to ASD and measurement artifacts. We used contrastive deep learning to disentangle ASD-specific neuroanatomical variation from variation shared with typical control participants. ASD-specific variation correlated with individual differences in symptoms. The structure of this ASD-specific variation also addresses a long-standing debate about the nature of ASD: At least in terms of neuroanatomy, individuals do not cluster into distinct subtypes; instead, they are organized along continuous dimensions that affect distinct sets of regions.


Assuntos
Transtorno do Espectro Autista , Encéfalo , Aprendizado Profundo , Transtorno do Espectro Autista/patologia , Encéfalo/anormalidades , Neuroimagem Funcional , Humanos , Neuroanatomia
14.
Brain Struct Funct ; 227(6): 2191-2207, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35672532

RESUMO

Efficient communication across fields of research is challenging, especially when they are at opposite ends of the physical and digital spectrum. Neuroanatomy and neuroimaging may seem close to each other. When neuroimaging studies try to isolate structures of interest, according to a specific anatomical definition, a variety of challenges emerge. It is a non-trivial task to convert the neuroanatomical knowledge to instructions and rules to be executed in neuroimaging software. In the process called "virtual dissection" used to isolate coherent white matter structure in tractography, each white matter pathway has its own set of landmarks (regions of interest) used as inclusion and exclusion criteria. The ability to segment and study these pathways is critical for scientific progress, yet, variability may depend on region placement, and be influenced by the person positioning the region (i.e., a rater). When raters' variability is taken into account, the impact made by each region of interest becomes even more difficult to interpret. A delicate balance between anatomical validity, impact on the virtual dissection and raters' reproducibility emerge. In this work, we investigate this balance by leveraging manual delineation data of a group of raters from a previous study to quantify which set of landmarks and criteria contribute most to variability in virtual dissection. To supplement our analysis, the variability of each pathway with a region-by-region exploration was performed. We present a detailed exploration and description of each region, the causes of variability and its impacts. Finally, we provide a brief overview of the lessons learned from our previous virtual dissection projects and propose recommendations for future virtual dissection protocols as well as perspectives to reach better community agreement when it comes to anatomical definitions of white matter pathways.


Assuntos
Substância Branca , Dissecação , Humanos , Processamento de Imagem Assistida por Computador/métodos , Neuroanatomia , Neuroimagem , Reprodutibilidade dos Testes , Substância Branca/diagnóstico por imagem
15.
J Cogn Neurosci ; 34(8): 1355-1375, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35640102

RESUMO

The neural basis of language has been studied for centuries, yet the networks critically involved in simply identifying or understanding a spoken word remain elusive. Several functional-anatomical models of critical neural substrates of receptive speech have been proposed, including (1) auditory-related regions in the left mid-posterior superior temporal lobe, (2) motor-related regions in the left frontal lobe (in normal and/or noisy conditions), (3) the left anterior superior temporal lobe, or (4) bilateral mid-posterior superior temporal areas. One difficulty in comparing these models is that they often focus on different aspects of the sound-to-meaning pathway and are supported by different types of stimuli and tasks. Two auditory tasks that are typically used in separate studies-syllable discrimination and word comprehension-often yield different conclusions. We assessed syllable discrimination (words and nonwords) and word comprehension (clear speech and with a noise masker) in 158 individuals with focal brain damage: left (n = 113) or right (n = 19) hemisphere stroke, left (n = 18) or right (n = 8) anterior temporal lobectomy, and 26 neurologically intact controls. Discrimination and comprehension tasks are doubly dissociable both behaviorally and neurologically. In support of a bilateral model, clear speech comprehension was near ceiling in 95% of left stroke cases and right temporal damage impaired syllable discrimination. Lesion-symptom mapping analyses for the syllable discrimination and noisy word comprehension tasks each implicated most of the left superior temporal gyrus. Comprehension but not discrimination tasks also implicated the left posterior middle temporal gyrus, whereas discrimination but not comprehension tasks also implicated more dorsal sensorimotor regions in posterior perisylvian cortex.


Assuntos
Percepção da Fala , Acidente Vascular Cerebral , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Neuroanatomia , Fala , Acidente Vascular Cerebral/patologia , Lobo Temporal/patologia
16.
Hum Brain Mapp ; 43(14): 4310-4325, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35607841

RESUMO

Skilled reading is important in daily life. While the understanding of the neurofunctional organization of this uniquely human skill has advanced significantly, it does not take into consideration the common bilingual experiences around the world. To examine the role of early bilingualism on the neural substrates supporting English word processing, we compared brain activity, as well as functional connectivity, in Spanish-English early bilingual adults (N = 25) and English monolingual adults (N = 33) during single-word processing. Activation analysis revealed no significant differences between the two groups. A seed-to-voxel analysis using eight a priori selected seed-regions (placed in regions known to be involved in reading) revealed relatively stronger functional connectivity in bilinguals between two sets of regions: left superior temporal gyrus seed positively with left lingual gyrus and left middle frontal gyrus seed negatively with left anterior cingulate cortex. Together these results suggest that an early Spanish-English bilingual experience does not modulate local brain activity for English word reading. It does, however, have some influence on the functional intercommunication between brain regions during reading, specifically in two regions associated with reading, which are functionally connected to those inside and outside of the reading network. We conclude that brain regions involved in processing English words are not that different in Spanish-English early bilingual adults relative to monolingual adult users of English.


Assuntos
Multilinguismo , Neuroanatomia , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico , Humanos , Lobo Temporal
17.
Int J Mol Sci ; 23(10)2022 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-35628615

RESUMO

In the last decades, new evidence on brain structure and function has been acquired by morphological investigations based on synergic interactions between biochemical anatomy approaches, new techniques in microscopy and brain imaging, and quantitative analysis of the obtained images. This effort produced an expanded view on brain architecture, illustrating the central nervous system as a huge network of cells and regions in which intercellular communication processes, involving not only neurons but also other cell populations, virtually determine all aspects of the integrative function performed by the system. The main features of these processes are described. They include the two basic modes of intercellular communication identified (i.e., wiring and volume transmission) and mechanisms modulating the intercellular signaling, such as cotransmission and allosteric receptor-receptor interactions. These features may also open new possibilities for the development of novel pharmacological approaches to address central nervous system diseases. This aspect, with a potential major impact on molecular medicine, will be also briefly discussed.


Assuntos
Neuroanatomia , Neurofarmacologia , Comunicação Celular/fisiologia , Sistema Nervoso Central/fisiologia , Modelos Neurológicos
18.
J Neuroendocrinol ; 34(5): e13115, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35502534

RESUMO

The anatomy and morphology of gonadotropin-releasing hormone (GnRH) neurons makes them both a joy and a challenge to investigate. They are a highly unique population of neurons given their developmental migration into the brain from the olfactory placode, their relatively small number, their largely scattered distribution within the rostral forebrain, and, in some species, their highly varied individual anatomical characteristics. These unique features have posed technological hurdles to overcome and promoted fertile ground for the establishment and use of creative approaches. Historical and more contemporary discoveries defining GnRH neuron anatomy remain critical in shaping and challenging our views of GnRH neuron function in the regulation of reproductive function. We begin this review with a historical overview of anatomical discoveries and developing methodologies that have shaped our understanding of the reproductive axis. We then highlight significant discoveries across specific groups of mammalian species to address some of the important comparative aspects of GnRH neuroanatomy. Lastly, we touch on unresolved questions and opportunities for future neuroanatomical research on this fascinating and important population of neurons.


Assuntos
Hormônio Liberador de Gonadotropina , Neuroanatomia , Animais , Hormônio Liberador de Gonadotropina/metabolismo , Mamíferos , Neurônios/metabolismo , Prosencéfalo , Reprodução
19.
J Comp Neurol ; 530(14): 2416-2438, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35593178

RESUMO

The central complex (CX) in the brain of insects is a highly conserved group of midline-spanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution three-dimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.


Assuntos
Neurônios , Neurópilo , Animais , Abelhas , Encéfalo , Insetos , Neuroanatomia
20.
Neuroimage ; 257: 119243, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35508216

RESUMO

Although initially showing great potential, oxytocin treatment has encountered a translational hurdle in its promise of treating the social deficits of autism. Some debate surrounds the ability of oxytocin to successfully enter the brain, and therefore modify neuroanatomy. Moreover, given the heterogeneous nature of autism, treatment will only amerliorate symptoms in a subset of patients. Therefore, to determine whether oxytocin changes brain circuitry, and whether it does so variably, depending on genotype, we implemented a large randomized, blinded, placebo-controlled, preclinical study on chronic intranasal oxytocin treatment in three different mouse models related to autism with a focus on using neuroanatomical phenotypes to assess and subset treatment response. Intranasal oxytocin (0.6IU) was administered daily, for 28 days, starting at 5 weeks of age to the 16p11.2 deletion, Shank3 (exon 4-9) knockout, and Fmr1 knockout mouse models. Given the sensitivity of structural magnetic resonance imaging (MRI) to the neurological effects of interventions like drugs, along with many other advantages, the mice underwent in vivo longitudinal and high-resolution ex vivo imaging with MRI. The scans included three in vivo T1weighted, 90 um isotropic resolution scans and a T2-weighted, 3D fast spin echo with 40um isotropic resolution ex vivo scan to assess the changes in neuroanatomy using established automated image registration and deformation based morphometry approaches in response to oxytocin treatment. The behavior of the mice was assessed in multiple domains, including social behaviours and repetitive behaviours, among others. Treatment effect on the neuroanatomy did not reach significance, although the pattern of trending effects was promising. No significant effect of treatment was found on social behavior in any of the strains, although a significant effect of treatment was found in the Fmr1 mouse, with treatment normalizing a grooming deficit. No other treatment effect on behavior was observed that survived multiple comparisons correction. Overall, chronic treatment with oxytocin had limited effects on the three mouse models related to autism, and no promising pattern of response susceptibility emerged.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Ocitocina , Administração Intranasal , Animais , Transtorno do Espectro Autista/tratamento farmacológico , Transtorno Autístico/tratamento farmacológico , Modelos Animais de Doenças , Proteína do X Frágil de Retardo Mental , Humanos , Camundongos , Proteínas dos Microfilamentos/uso terapêutico , Proteínas do Tecido Nervoso , Neuroanatomia , Ocitocina/farmacologia , Distribuição Aleatória , Comportamento Social
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