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1.
EMBO J ; 39(13): e104163, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32484994

RESUMO

The relationships between impaired cortical development and consequent malformations in neurodevelopmental disorders, as well as the genes implicated in these processes, are not fully elucidated to date. In this study, we report six novel cases of patients affected by BBSOAS (Boonstra-Bosch-Schaff optic atrophy syndrome), a newly emerging rare neurodevelopmental disorder, caused by loss-of-function mutations of the transcriptional regulator NR2F1. Young patients with NR2F1 haploinsufficiency display mild to moderate intellectual disability and show reproducible polymicrogyria-like brain malformations in the parietal and occipital cortex. Using a recently established BBSOAS mouse model, we found that Nr2f1 regionally controls long-term self-renewal of neural progenitor cells via modulation of cell cycle genes and key cortical development master genes, such as Pax6. In the human fetal cortex, distinct NR2F1 expression levels encompass gyri and sulci and correlate with local degrees of neurogenic activity. In addition, reduced NR2F1 levels in cerebral organoids affect neurogenesis and PAX6 expression. We propose NR2F1 as an area-specific regulator of mouse and human brain morphology and a novel causative gene of abnormal gyrification.


Assuntos
Fator I de Transcrição COUP/metabolismo , Neocórtex/embriologia , Células-Tronco Neurais/metabolismo , Lobo Occipital/embriologia , Atrofias Ópticas Hereditárias/embriologia , Lobo Parietal/embriologia , Animais , Fator I de Transcrição COUP/genética , Modelos Animais de Doenças , Humanos , Camundongos , Neocórtex/patologia , Células-Tronco Neurais/patologia , Lobo Occipital/patologia , Atrofias Ópticas Hereditárias/genética , Atrofias Ópticas Hereditárias/patologia , Fator de Transcrição PAX6/genética , Fator de Transcrição PAX6/metabolismo , Lobo Parietal/patologia
2.
Dev Psychopathol ; 30(3): 743-762, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30068407

RESUMO

The prenatal period is increasingly considered as a crucial target for the primary prevention of neurodevelopmental and psychiatric disorders. Understanding their pathophysiological mechanisms remains a great challenge. Our review reveals new insights from prenatal brain development research, involving (epi)genetic research, neuroscience, recent imaging techniques, physical modeling, and computational simulation studies. Studies examining the effect of prenatal exposure to maternal distress on offspring brain development, using brain imaging techniques, reveal effects at birth and up into adulthood. Structural and functional changes are observed in several brain regions including the prefrontal, parietal, and temporal lobes, as well as the cerebellum, hippocampus, and amygdala. Furthermore, alterations are seen in functional connectivity of amygdalar-thalamus networks and in intrinsic brain networks, including default mode and attentional networks. The observed changes underlie offspring behavioral, cognitive, emotional development, and susceptibility to neurodevelopmental and psychiatric disorders. It is concluded that used brain measures have not yet been validated with regard to sensitivity, specificity, accuracy, or robustness in predicting neurodevelopmental and psychiatric disorders. Therefore, more prospective long-term longitudinal follow-up studies starting early in pregnancy should be carried out, in order to examine brain developmental measures as mediators in mediating the link between prenatal stress and offspring behavioral, cognitive, and emotional problems and susceptibility for disorders.


Assuntos
Encéfalo/embriologia , Encéfalo/fisiopatologia , Transtornos do Neurodesenvolvimento/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Estresse Psicológico/complicações , Tonsila do Cerebelo/embriologia , Tonsila do Cerebelo/fisiopatologia , Cerebelo/embriologia , Cerebelo/fisiopatologia , Feminino , Hipocampo/embriologia , Hipocampo/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Rede Nervosa/embriologia , Rede Nervosa/fisiopatologia , Transtornos do Neurodesenvolvimento/psicologia , Lobo Parietal/embriologia , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/embriologia , Córtex Pré-Frontal/fisiopatologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/psicologia , Estudos Prospectivos , Fatores de Risco , Lobo Temporal/embriologia , Lobo Temporal/fisiopatologia
3.
Ultrasound Obstet Gynecol ; 47(2): 217-23, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25728404

RESUMO

OBJECTIVE: To determine the association between sonographic assessment of fetal biparietal diameter (BPD) and pregnancy outcome. METHODS: This was a retrospective cohort study of pregnancies at 37-42 weeks of gestation which had antepartum sonographic measurement of BPD within 7 days before delivery. Eligibility was limited to singleton pregnancies with neither known structural or chromosomal abnormalities nor prelabor Cesarean delivery (CD). The association of BPD with outcome was analyzed using multivariate logistic regression, receiver-operating characteristics curves and stratification according to BPD quartiles. RESULTS: In total, 3229 women were eligible for analysis, of whom 2483 (76.9%) had a spontaneous vaginal delivery (SVD), 418 (12.9%) underwent operative vaginal delivery (OVD) and 328 (10.2%) underwent CD. The mean BPD in the obstetric intervention groups (OVD and CD) was significantly higher than that in the SVD group (P < 0.001). After adjusting for confounders, increased BPD was an independent risk factor such that higher values of BPD were associated with progressively higher risk of obstetric intervention (adjusted odds ratio, 1.05 for each 1-mm increase in BPD (95% CI, 1.02-1.09)), but no clear cut-off value for obstetric intervention was found. The fourth quartile group (BPD ≥ 97 mm) was associated with a significantly lower SVD rate (P < 0.001) and higher OVD rate (P = 0.04), relative to the first (BPD 88-90 mm) and second (BPD 91-93 mm) quartile groups, with no apparent adverse impact on immediate neonatal outcome. CONCLUSIONS: Increased BPD within the week prior to delivery is an independent risk factor such that higher values of BPD are associated with progressively higher risk of obstetric intervention; however, in our experience, no adverse neonatal outcome resulted from such intervention. Thus, increased BPD should not discourage a trial of vaginal delivery.


Assuntos
Parto Obstétrico/estatística & dados numéricos , Desenvolvimento Fetal , Lobo Parietal/diagnóstico por imagem , Resultado da Gravidez , Ultrassonografia Pré-Natal/métodos , Adulto , Parto Obstétrico/métodos , Feminino , Humanos , Modelos Logísticos , Análise Multivariada , Complicações do Trabalho de Parto/etiologia , Tamanho do Órgão , Lobo Parietal/embriologia , Lobo Parietal/crescimento & desenvolvimento , Valor Preditivo dos Testes , Gravidez , Curva ROC , Estudos Retrospectivos , Fatores de Risco
4.
J Ultrasound Med ; 33(7): 1165-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24958402

RESUMO

OBJECTIVES: To determine whether the biparietal diameter measurement is altered in first-trimester fetuses with holoprosencephaly. METHODS: Cases of holoprosencephaly were collected retrospectively from 4 fetal medicine centers, and first-trimester biparietal diameter measurements were reviewed. The diagnosis of holoprosencephaly was established sonographically by the detection of abnormal choroid plexus morphologic characteristics (absent "butterfly" sign) and the identification of a monoventricular cerebral cavity on axial views of the fetal brain. The proportion of fetuses with biparietal diameter measurements below the 5th percentile for crown-rump length was determined. RESULTS: Among 45 cases of holoprosencephaly reviewed, 43 had information on both biparietal diameter and crown-rump length measurements. The biparietal diameter was below the 5th percentile for crown-rump length in 14 (32.6%) fetuses. Chromosomal analysis was available in 41; no statistically significant difference in biparietal diameter measurement between those with associated chromosomal anomalies and those without anomalies was noted. A supplementary analysis using head circumference measurement showed an even greater proportion of fetuses with holoprosencephaly with measurements below the 5th percentile for crown-rump length (18 of 42 [42.9%]). CONCLUSIONS: One-third of first-trimester fetuses with a sonographic diagnosis of holoprosencephaly had a biparietal diameter that was smaller than expected for crown-rump length. In this subset of fetuses, the evaluation of intracranial anatomy for signs of holoprosencephaly may be more difficult to perform due to the smaller size of the brain. Therefore, the detection of a biparietal diameter below the 5th percentile as expected from crown-rump length on the first-trimester scan may be a warning sign of holoprosencephaly and should prompt a detailed examination of the intracranial anatomy.


Assuntos
Estatura Cabeça-Cóccix , Doenças Fetais/diagnóstico por imagem , Holoprosencefalia/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Ultrassonografia Pré-Natal , Feminino , Doenças Fetais/fisiopatologia , Holoprosencefalia/embriologia , Holoprosencefalia/fisiopatologia , Humanos , Lobo Parietal/embriologia , Gravidez , Primeiro Trimestre da Gravidez , Estudos Retrospectivos
5.
Hum Brain Mapp ; 34(10): 2494-510, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22461404

RESUMO

Recent in vivo neuroimaging studies revealed that several brain networks are altered in prenatal cocaine exposure (PCE) affected adolescent brains. However, due to a lack of dense and corresponding cortical landmarks across individuals, the systematical alterations of functional connectivities in large-scale brain networks and the alteration of structural brain architecture in PCE affected brain are largely unknown. In this article, we adopted a newly developed data-driven strategy to build a large set of cortical landmarks that are consistent and corresponding across PCE adolescents and their matched controls. Based on these landmarks, we constructed large-scale functional connectomes and applied the well-established approaches of deriving genomics signatures in genome-wide gene expression studies to discover functional connectomics signatures for the characterization of PCE adolescent brains. Results derived from experimental data demonstrated that 10 structurally disrupted landmarks were identified in PCE, and more importantly, the discovered informative functional connectomics signatures among consistent landmarks distinctively differentiate PCE brains from their matched controls.


Assuntos
Adolescente , Pontos de Referência Anatômicos/patologia , Encéfalo/efeitos dos fármacos , Cocaína/efeitos adversos , Conectoma , Neuroimagem/métodos , Efeitos Tardios da Exposição Pré-Natal/patologia , Algoritmos , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Estudos de Casos e Controles , Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Feminino , Seguimentos , Perfilação da Expressão Gênica , Humanos , Masculino , Troca Materno-Fetal , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/embriologia , Lobo Parietal/crescimento & desenvolvimento , Gravidez , Complicações na Gravidez/fisiopatologia
6.
J Ultrasound Med ; 32(2): 269-77, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23341383

RESUMO

OBJECTIVES: To determine reference ranges for measurements of fetal cerebral fissures by 3-dimensional (3D) sonography in the multiplanar mode and to evaluate the reliability and concordance of these measurements. METHODS: A cross-sectional study was conducted on 393 women with normal pregnancies at 22 weeks to 33 weeks 6 days. The distances between the internal bone plate of the fetal calvaria and the sylvian, parieto-occipital, hippocampal, and calcarine fissures were assessed. To obtain the distances for the first 3 fissures, a 3D sweep was made in the axial plane, at the level of the lateral ventricles. To obtain the distance for the calcarine fissure, a coronal sweep was used, at the level of the occipital lobes. To evaluate the correlation between the fissures and gestational age, polynomial regression was performed with adjustments using the coefficient of determination (R(2)). Reliability was determined with intraclass correlation coefficients and concordance with concordance limits. RESULTS: The mean distances ± SD to the sylvian, parieto-occipital, hippocampal, and calcarine fissures were 10.42 ± 2.28, 22.38 ± 3.23, 24.88 ± 4.67, and 21.19 ± 2.73 mm, respectively. These distances correlated with gestational age such that the best fit with the linear equation produced R(2) values of 0.582, 0.627, 0.860, and 0.458 for the sylvian, parieto-occipital, hippocampal, and calcarine fissures. Reliability analyses showed intraobserver and interobserver intraclass correlation coefficients of 0.90 to 0.95 and 0.85 to 0.97. The concordance limits were-1.33 to 1.30 and -2.38 to 2.28 mm for the intraobserver evaluation and -1.60 to 2.57 and -3.51 to 2.73 mm for the interobserver evaluation. CONCLUSIONS: Cerebral fissures can be measured by 3D sonography at 22 to 33 weeks of pregnancy with acceptable reliability and concordance. Reference ranges for this gestational period have thus been described.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/embriologia , Ecoencefalografia/métodos , Imageamento Tridimensional , Segundo Trimestre da Gravidez , Ultrassonografia Pré-Natal , Adolescente , Adulto , Córtex Cerebral/anatomia & histologia , Estudos Transversais , Feminino , Idade Gestacional , Hipocampo/diagnóstico por imagem , Hipocampo/embriologia , Humanos , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/embriologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/embriologia , Gravidez , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Adulto Jovem
7.
Dev Neurosci ; 33(2): 99-109, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21613774

RESUMO

The principal function of the γ-aminobutyric acid (GABA) system in the adult brain is inhibition; however, in the neonatal brain, GABA provides much of the excitatory drive. As the brain develops, transmembrane chloride gradients change and the inhibitory role of GABA is initiated and continues throughout juvenile and adult life. Previous studies have shown that GABA(A) receptor subunit expression is developmentally regulated, and it is thought that the change in GABA function from excitation to inhibition corresponds to the changeover in expression of 'immature' to 'mature' subunit isoforms. We examined the protein expression pattern and distribution of GABA type A (GABA(A)) receptor α1-, α3- and ß2-subunits in the parietal cortex and hippocampus of the developing piglet brain. Four perinatal ages were studied; 14 days preterm (P-14), 10 days preterm (P-10), day of birth (P0) and at postnatal day 7 (P7). Animals were obtained by either caesarean section or spontaneous birth. Protein expression levels and subunit localization were analysed by Western blotting and immunohistochemistry, respectively. In the cortex and hippocampus, GABA(A) receptor α1-subunit showed greatest expression at P7 when compared to all other age groups (p < 0.05). In contrast, α3 expression in the cortex was elevated in preterm brain, peaking at P0, followed by a significant reduction by P7 (p < 0.05); a similar trend was observed in the hippocampus. GABA(A) receptor ß2-subunit protein expression appeared relatively constant across all time points studied in both the cortex and hippocampus. Immunolabelling of the α1-, α3- and ß2-subunits was observed throughout all cortical layers at every age. GABA(A) receptor α3-subunit appeared to show specific localization to layers V and VI whilst labelling for the ß2-subunit was observed in layer IV. In the hippocampus of all animals, the α1- and ß2-subunits were shown to immunolabel various cells and processes in the dentate gyrus (DG), CA1 and CA3; the α3-subunit was barely observed except at the stratum moleculare of the DG. We report for the first time the ontogenesis of GABA(A) receptor subunits α1, α3 and ß2 in the perinatal pig brain.


Assuntos
Encéfalo/metabolismo , Hipocampo , Lobo Parietal , Subunidades Proteicas/metabolismo , Receptores de GABA-A , Animais , Animais Recém-Nascidos/metabolismo , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Idade Gestacional , Hipocampo/embriologia , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Humanos , Imuno-Histoquímica , Lobo Parietal/embriologia , Lobo Parietal/crescimento & desenvolvimento , Lobo Parietal/metabolismo , Ratos , Receptores de GABA-A/análise , Receptores de GABA-A/metabolismo , Sus scrofa , Fatores de Tempo , Distribuição Tecidual , Ácido gama-Aminobutírico/metabolismo
8.
Gynecol Obstet Fertil ; 37(4): 367-71, 2009 Apr.
Artigo em Francês | MEDLINE | ID: mdl-19362034

RESUMO

OBJECTIVES: The aim of this study was to evaluate the accuracy of ultrasound fetal weight prediction at due date and to find parameters that may affect this prediction. PATIENTS AND METHODS: We retrospectively studied 201 patients at due date in a university hospital in 2006, the fetal weight estimation being performed by Obstetric-gynecology (OB-Gyn). Estimated fetal weight was calculated with the Hadlock's formula, including biparietal diameter, cephalic circumference, abdominal perimeter and femoral length and was compared with birth weight. RESULTS: The mean birth weight was 3561+/-415 g. The mean absolute weight difference was 261+/-190 g (absolute range: 0 to 1183 g, actual range: -935 to 1183 g). Body mass index>30 kg/m(2) was associated with greater fetal weight inaccuracy (p=0,013). Fetal weight estimation was not influenced by fetal macrosomia, oligoanamnios or maternal weight gain during pregnancy. DISCUSSION AND CONCLUSION: The sonographic estimated fetal weight and birth weight are correlated with a mean absolute percentage error of 7%. However, clinicians should be aware of the risk of inaccuracy in obese women.


Assuntos
Peso ao Nascer , Peso Fetal , Abdome/anatomia & histologia , Abdome/embriologia , Feminino , Fêmur/anatomia & histologia , Fêmur/embriologia , Humanos , Recém-Nascido , Internato e Residência , Lobo Parietal/anatomia & histologia , Lobo Parietal/embriologia , Paridade , Gravidez , Estudos Retrospectivos , Crânio/anatomia & histologia , Crânio/embriologia
9.
Invest Clin ; 50(4): 465-78, 2009 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-20306720

RESUMO

The effects of prenatal expossure to paraquat (PQ) were studied on postnatal development of mouse parietal cerebral cortex, in particular, the ontogenesis of amino acid synaptic transmission. Pregnant NMRI mice were separated into two groups: the experimental group received 5 doses of 10 mg PQ/kg body weight, between days of gestation (G)12 and G20, whereas the control group received physiological saline solution. Levels of neurotransmitter amino acids: Asp, Glu, Gly, GABA and Tau were determined by HPLC between postnatal (P) days P1 and P30. Between P3 and P15, a significant increment in the levels of excitatory amino acids, Asp and Glu, were observed in mice exposed to PQ, as compared with the control group. With respect to the inhibitory neurotransmitter levels, in the group exposed to PQ, the more important changes were observed in Gly between P1 and P15. In relation to taurine, its levels remained significantly higher between P1 and P7 with respect to the control group. It is important to emphasize that at P30, the levels of all neurotransmitters in the experimental group were significantly lower than those of control. In conclusion, prenatal exposure to PQ caused neurotoxicity in the developing mouse parietal cortex, as shown by the alterations in the basal levels of amino acid neurotransmitters, with the excitatory predominating over inhibitory neurotransmission, throughout the studied developmental period. These alterations could indicate the occurrence of important cortical injuries, such as decrement in some neuronal populations, inadequate formation of intrinsic cortical circuits and alterations in synaptogenic processes.


Assuntos
Aminoácidos/fisiologia , Herbicidas/efeitos adversos , Exposição Materna/efeitos adversos , Paraquat/efeitos adversos , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/embriologia , Transmissão Sináptica/efeitos dos fármacos , Animais , Feminino , Camundongos
10.
Dev Neurosci ; 30(1-3): 211-20, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18075267

RESUMO

The subplate is a transient structure essential for normal development of the cortex. We used magnetic resonance imaging of the fetal brain to assess cortical subplate evolution between 20 and 35 weeks gestation. Two-dimensional measures of diameter were obtained for the cortex, subplate and fetal white matter. The subplate was originally seen as a continuous band at early gestations measuring up to 4.5 mm. It became magnetic resonance invisible from approximately 28 weeks initially from the depths of the sulci and then from the tops of the gyri. The disappearance of the subplate was regional, involuting most rapidly in the parietal lobe and remaining prominent in the anterior temporal lobe up to 35 weeks. x


Assuntos
Movimento Celular/fisiologia , Córtex Cerebral/embriologia , Feto/embriologia , Imageamento por Ressonância Magnética/métodos , Neurônios/fisiologia , Células-Tronco/fisiologia , Mapeamento Encefálico/métodos , Diferenciação Celular/fisiologia , Córtex Cerebral/fisiologia , Ventrículos Cerebrais/embriologia , Ventrículos Cerebrais/fisiologia , Feminino , Desenvolvimento Fetal/fisiologia , Feto/fisiologia , Idade Gestacional , Humanos , Processamento de Imagem Assistida por Computador/métodos , Vias Neurais/embriologia , Vias Neurais/fisiologia , Neurônios/citologia , Lobo Parietal/embriologia , Lobo Parietal/fisiologia , Gravidez , Células-Tronco/citologia , Telencéfalo/embriologia , Telencéfalo/fisiologia , Lobo Temporal/embriologia , Lobo Temporal/fisiologia , Fatores de Tempo
11.
Anat Embryol (Berl) ; 211(6): 757-64, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17072644

RESUMO

This study aimed to clarify the development of sulci and gyri on the external surface of the cerebrum of cynomolgus monkeys. Sulcus formation began with the appearance of the lateral fissure on embryonic day (ED) 70, followed by delineations of four cerebral lobes by the emergence of the parietooccipital sulcus, central sulcus, and preoccipital notch on EDs 80-90. The following primary sulci were then visible until ED 120: the superior temporal sulcus on ED 90; the intraparietal sulcus, lunate sulcus, inferior occipital sulcus, and arcuate sulcus on ED 100; and the principle sulcus on ED 110; the occipitotemporal sulcus, anterior middle temporal sulcus, and superior postcentral dimple on ED 120. These sulci demarcated the superior temporal gyrus on ED 90, the precentral gyrus, supramarginal gyrus, and angular gyrus on ED 100, and the inferior and middle temporal gyri, postocentral gyrus, superior parietal lobule, superior, middle and inferior frontal gyri, and inferior occipital gyrus on ED 120. Except for the intermediate and lateral orbitofrontal sulci, the sulci that appeared on ED 130 and thereafter were not related to the gyrus demarcations. Intriguingly, the brain markedly gained weight on EDs 100 and 120, corresponding to the embryonic ages when almost all gyri were visible. The results suggest that a rapid growth of the cerebrum involves convolutions of the gyri by a regular sequence of the sulcus formation in cynomolgus monkeys. This study further provides a standard of reference for normal development in the cerebral cortical morphology of cynomolgus monkeys.


Assuntos
Giro do Cíngulo/embriologia , Macaca fascicularis/embriologia , Telencéfalo/embriologia , Animais , Encéfalo/anatomia & histologia , Encéfalo/embriologia , Feminino , Lobo Frontal/embriologia , Masculino , Modelos Biológicos , Tamanho do Órgão , Lobo Parietal/embriologia , Lobo Temporal/embriologia
12.
J Comp Neurol ; 484(2): 156-67, 2005 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-15736232

RESUMO

After completion of neuronal migration to form the cerebral cortex, axons undergo rapid elongation to their intra- and subcortical targets, from midgestation through infancy. We define axonal development in the human parietal white matter in this critical period. Immunocytochemistry and Western blot analysis were performed on 46 normative cases from 20-183 postconceptional (PC) weeks. Anti-SMI 312, a pan-marker of neurofilaments, stained axons as early as 23 weeks. Anti-SMI 32, a marker for nonphosphorylated neurofilament high molecular weight (NFH), primarily stained neuronal cell bodies (cortical, subcortical, and Cajal-Retzius). Anti-SMI 31, which stains phosphorylated NFH, was used as a marker of axonal maturity, and showed relatively low levels of staining (approximately one-fourth of adult levels) from 24-34 PC weeks. GAP-43, a marker of axonal growth and elongation, showed high levels of expression in the white matter from 21-64 PC weeks and lower, adult-like levels beyond 17 postnatal months. The onset of myelination, as seen by myelin basic protein expression, was approximately 54 weeks, with progression to "adult-like" staining by 72-92 PC weeks. This study provides major insight into axonal maturation during a critical period of growth, over an age range not previously examined and one coinciding with the peak period of periventricular leukomalacia (PVL), the major disorder underlying cerebral palsy in premature infants. These data suggest that immature axons are susceptible to damage in PVL and that the timing of axonal maturation must be considered toward establishing its pathology relative to the oligodendrocyte/myelin/axonal unit.


Assuntos
Axônios/fisiologia , Feto/embriologia , Fibras Nervosas Mielinizadas/fisiologia , Telencéfalo/embriologia , Telencéfalo/crescimento & desenvolvimento , Adulto , Pré-Escolar , Feto/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Lactente , Recém-Nascido , Lobo Parietal/embriologia , Lobo Parietal/crescimento & desenvolvimento
13.
J Comp Neurol ; 442(1): 35-47, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11754365

RESUMO

Neuropeptide Y (NPY) is present in most cerebrocortical areas during fetal and postnatal development. In the rat frontal cortex, a dense radial fiber network containing NPY immunoreactivity is observed transiently as early as embryonic day 17 (E17) and disappears at the end of the first postnatal week. We have investigated the distribution of NPY receptors in the frontoparietal cortex at 13 stages of development, from E15 fetuses to adults, by in vitro autoradiography, using (125)I-pPYY as a radioligand. Quantitative receptor density was measured through all cortical layers at each developmental stage. Pharmacological identification of (125)I-pPPY binding sites was made by competition experiments using pNPY or [Leu(31),Pro(34)]pNPY and pNPY(13-36), as selective competitors for Y1 and Y2 receptors, respectively. NPY receptors were first detected in the cerebral cortex at low densities at E19 in a thin layer of tissue corresponding to the inner half of the intermediate zone (IZ) and the upper ventricular zone (VZ). The neuroepithelium did not contain binding sites. High densities of sites were observed by E21 onward to P10 in the deep cortical layers corresponding to the IZ and layers V-VI. A decreasing gradient of receptor density was observed from layer VI to the marginal zone (layer I). The distribution of NPY receptors does not match with the perikarya of transient NPY-immunoreactive neurons located in the cortical plate but does coincide with their axonal extension. The receptor density decreased abruptly between P10 and P12 in deep layers, whereas a moderate expression of binding sites is detected from P10 to P12 in layers I-III. By P14, the binding level was the lowest observed in the postnatal period. From P21 onward, receptors were observed in superficial layers I-III, and their density rose by two- to threefold up to adulthood. Competition studies indicated that the NPY receptors located in the deep cortical layers of the E21 or P1 rat cortex exhibit Y2 receptor type characteristics. The binding sites detected in the superficial layers from P10 to P12 rats also show Y2 receptors characteristics, unlike the NPY receptors in layers II-III of the adult, which behave like Y1 receptors. These data show that different NPY receptor types are successively expressed in specific layers during late gestation and early postnatal life in the rat frontoparietal cortex.


Assuntos
Diferenciação Celular/fisiologia , Lobo Frontal/metabolismo , Neurônios/metabolismo , Neuropeptídeo Y/análogos & derivados , Neuropeptídeo Y/metabolismo , Lobo Parietal/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Células-Tronco/metabolismo , Envelhecimento/fisiologia , Animais , Animais Recém-Nascidos , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/fisiologia , Feminino , Feto , Lobo Frontal/embriologia , Lobo Frontal/crescimento & desenvolvimento , Radioisótopos do Iodo/farmacocinética , Neurônios/citologia , Neuropeptídeo Y/farmacocinética , Lobo Parietal/embriologia , Lobo Parietal/crescimento & desenvolvimento , Fragmentos de Peptídeos/farmacocinética , Peptídeo YY/farmacocinética , Gravidez , Ensaio Radioligante , Ratos , Ratos Wistar , Células-Tronco/citologia
14.
Neuroreport ; 5(2): 133-6, 1993 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-7906557

RESUMO

Repair of mechanically injured primary somatosensory cortex in 3 week old mice was studied by placing small, solid foetal neurotransplants into large cortical cavities. After transplantation, the graft and host tissues were distinguished immunocytochemically owing to their expression of two different Thy-1 antigens. Cell proliferation was monitored by 3H-thymidine autoradiography. The following observations were made two months after operation: (i) In 8 out of 11 grafted animals new cortical tissue had taken the place of the cavity. (ii) Five of these 8 animals contained only host tissue; the remainder presented a small piece of grafted tissue. (iii) In the restored cortical area, newly generated cells were predominantly of host origin. These data suggest that the restorative capacity of the already post-mitotic cerebral cortex is not lost and may be reactivated. The presence of a foetal neural graft seems to favour this process.


Assuntos
Transplante de Tecido Encefálico , Transplante de Tecido Fetal , Lobo Parietal/transplante , Córtex Somatossensorial/lesões , Fatores Etários , Animais , Antígenos de Superfície/análise , Biomarcadores , Divisão Celular , Glicoproteínas de Membrana/análise , Camundongos , Camundongos Endogâmicos C57BL , Regeneração Nervosa , Proteínas do Tecido Nervoso/análise , Lobo Parietal/embriologia , Córtex Somatossensorial/patologia , Córtex Somatossensorial/fisiologia , Antígenos Thy-1 , Cicatrização
15.
Brain Res ; 282(2): 131-40, 1983 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6831236

RESUMO

Trophic interactions during development of brain regions were examined in rats using intraocular grafts of central nervous tissue. The increase in volume of transplanted fetal parietal cerebral cortex, as measured through the cornea, was markedly augmented by the presence of several different previously grafted CNS areas such as locus coeruleus, tectum, or cerebral cortex. DNA measurements and histological examinations suggested that this increased volume was due both to hyperplasia and hypertrophy. Previous grafts of iris, in contrast, did not significantly alter the final size of subsequently grafted cortex pieces. Contact between the two transplants was found to be critical in eliciting the trophic response. Growth-stimulated cortical grafts had a better organized cyto-architecture with larger neurons, including typical pyramidal cells, more neuropil, a lower cell density, and a more organotypic distribution of the cell bodies than non-stimulated controls. The experiments thus demonstrate a profound effect of adjacent neural tissue on development of neocortex. It is concluded that trophic interactions upon brain development can be revealed by sequential intraocular grafting.


Assuntos
Córtex Cerebral/embriologia , Locus Cerúleo/embriologia , Colículos Superiores/embriologia , Animais , Córtex Cerebral/análise , DNA/análise , Indução Embrionária , Feminino , Proteína Glial Fibrilar Ácida , Proteínas de Filamentos Intermediários/metabolismo , Lobo Parietal/embriologia , Ratos , Ratos Endogâmicos
16.
Brain Res ; 393(1): 75-84, 1986 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3524758

RESUMO

Cortex cerebri pieces from fetal donors were homologously and bilaterally grafted to the anterior chamber of the eye of 1.5-, 3.0- and 7.5-month-old rats. Repeated stereoscopic in vivo measurements revealed that the grafts in the young group grew to a size twice as large as those in the older two groups. The degree of gliosis was studied immunohistochemically using antibodies against glial fibrillary acidic protein. Both grafts to young and to older hosts were clearly gliotic as compared to normal cerebral cortex. However, the gliosis was significantly more pronounced in grafts to 3.0- and 7.5-month-old hosts as compared to grafts to 1.5-month-old hosts. The vascular component was evaluated using antibodies against laminin. We found laminin immunofluorescence to be an excellent marker of brain tissue vascularization, particularly at the capillary level, revealing the entire capillary tree and endothelial budding. The density of the vascular plexus and the average thickness of the capillaries of cortex cerebri grafted to the youngest recipients was remarkably similar to normal cerebral cortex. In marked contrast, grafts to the older hosts had a clearly pathological vascular network characterized by few, thick-walled blood vessels and very few normal-looking capillaries. We conclude that host age factors profoundly influence development and growth of intraocular brain tissue grafts.


Assuntos
Lobo Parietal/embriologia , Animais , Vasos Sanguíneos/embriologia , Feto , Imunofluorescência , Proteína Glial Fibrilar Ácida/metabolismo , Laminina/metabolismo , Neuroglia/citologia , Lobo Parietal/metabolismo , Lobo Parietal/transplante , Ratos
17.
Brain Res ; 285(2): 171-80, 1983 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6351965

RESUMO

Pieces of cortex cerebri anlage were dissected out from 16- to 17-day-old fetuses and transplanted to the cortical and cerebellar regions of 5- to 6-day-old rat pups. Twelve animals with grafts in the cortical region and 5 animals with grafts in the cerebellar region were studied 1.5-4 months later. Cresyl violet stained sections revealed no gross difference in either cell morphology, cell density or cell distribution between grafts in the two locations. A molecular layer-like zone was present on all free surfaces of the grafts, whether facing a ventricle or the meninges. The astrocytic development was studied using immunohistochemistry with antibodies against glial fibrillary acidic protein, (GFA), and the S-100 protein. Both antibodies visualized starshaped astrocytes and perivascular membranes surrounding blood vessels. Semi-quantitative measurements as well as computerized image analysis showed that the total amount of GFA-like immunoreactivity was much higher in both types of grafts than in corresponding host cortex cerebri. No differences in amount of S-100-like immunoreactivity could be demonstrated. As S-100 is thought to be a more general astrocytic marker than GFA, this suggests that the difference in GFA-like immunoreactivity is due mainly to an increased amount of GFA within the individual astrocytes. It is concluded that grafts of fetal cortex cerebri pieces to the CNS of young hosts develop a profound astrocytic reaction characterized by an increased amount of GFA-like immunoreactivity.


Assuntos
Astrócitos/fisiologia , Lobo Parietal/transplante , Animais , Computadores , Imunofluorescência , Proteína Glial Fibrilar Ácida , Proteínas de Filamentos Intermediários/metabolismo , Lobo Parietal/citologia , Lobo Parietal/embriologia , Ratos , Ratos Endogâmicos , Proteínas S100/metabolismo
18.
Toxicology ; 65(3): 333-46, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1992564

RESUMO

Dithiocarbamates are known to form lipid-soluble complexes with lead and greatly increase brain lead levels. The present study was undertaken to investigate whether lead acetate, when administered together with disulfiram (Antabuse, metabolite of dithiocarbamate) during development, would induce morphological changes in brain astrocytes. Female Sprague-Dawley rats were given 0.25% lead acetate in the drinking water from day one of pregnancy and this treatment was continued after birth until the litters were 4 weeks old. In addition, some dams received disulfiram in a dose of 0.1 mmol/kg p.o. twice weekly and after parturition this dose was given s.c. directly to the offspring twice a week. Lead acetate and disulfiram treatments were discontinued at weaning and animals sacrificed 3 weeks later. Samples of parietal cortex, hippocampal formation and cerebellar cortex were dissected out and smeared onto glass-slides and astrocytes were visualized in toto using immunohistochemistry with antibodies against glial fibrillary acid protein (GFA), enabling morphometric analysis with a computerized image analyser. Animals treated with lead acetate showed a minor increase in the size of the GFA-immunoreactive astrocytes in parietal cortex smears, while animals treated with disulfiram showed no difference in size or form compared to controls. However, in combined lead acetate and disulfiram-treated animals a profound increase in astrocyte size and an increase in the number of processes of the individual GFA-immunoreactive astrocytes could be demonstrated in parietal cortex. No significant changes were noted in GFA-immunoreactive astrocytes of hippocampal smears following the different treatments, while GFA-immunoreactive astrocytes in cerebellar cortex smears were significantly smaller and had reduced number or processes following the combined lead acetate and disulfiram treatment compared to lead acetate treatment or controls. It is concluded that combined exposure to lead acetate and disulfiram during development induces regionally specific changes in GFA-immunoreactive astrocyte morphology. Furthermore, the present study demonstrates the usefulness of smear preparations combined with computerized image analysis to study the morphology of GFA-immunoreactive astrocytes as an index of toxic effects in CNS.


Assuntos
Astrócitos/efeitos dos fármacos , Dissulfiram/toxicidade , Compostos Organometálicos/toxicidade , Animais , Animais Lactentes , Peso Corporal/efeitos dos fármacos , Córtex Cerebelar/citologia , Córtex Cerebelar/efeitos dos fármacos , Córtex Cerebelar/embriologia , Interações Medicamentosas , Feminino , Proteína Glial Fibrilar Ácida/análise , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/embriologia , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Lobo Parietal/citologia , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/embriologia , Gravidez , Ratos
19.
J Child Neurol ; 18(1): 35-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12661936

RESUMO

We report two cases of leptomeningeal angiomatosis in atypical frontoparietotemporal locations without an associated facial port-wine stain. Evidence of a leptomeningeal angioma was found in each when they were evaluated for headaches and seizures. The diagnosis of a leptomeningeal angioma was suggested by calcifications noted on computed tomographic scan of the head and confirmed with contrast-enhanced magnetic resonance images of the brain. We hypothesize that given the lack of occipital involvement with the angioma, and therefore the noncontiguous nature of this lesion with the developing upper facial ectoderm, the failure to develop a facial angioma would be expected. We found that the useof an anticonvulsant along with a migraine prophylactic medication appeared to have the greatest efficacy in these two cases, whereas anticonvulsants alone were less helpful. This diagnosis should be considered in any child presenting with seizures or complicated migraines and intracranial calcifications.


Assuntos
Neoplasias Encefálicas/diagnóstico , Epilepsia do Lobo Temporal/diagnóstico , Neoplasias Faciais/diagnóstico , Lobo Frontal , Lobo Occipital , Lobo Parietal , Síndrome de Sturge-Weber/diagnóstico , Lobo Temporal , Adolescente , Animais , Neoplasias Encefálicas/embriologia , Neoplasias Encefálicas/genética , Artérias Cerebrais/embriologia , Artérias Cerebrais/patologia , Embrião de Galinha , Criança , Diagnóstico Diferencial , Dominância Cerebral/fisiologia , Eletroencefalografia , Epilepsia do Lobo Temporal/embriologia , Epilepsia do Lobo Temporal/genética , Neoplasias Faciais/embriologia , Neoplasias Faciais/genética , Feminino , Lobo Frontal/embriologia , Lobo Frontal/patologia , Humanos , Masculino , Meninges/irrigação sanguínea , Meninges/embriologia , Meninges/patologia , Lobo Occipital/embriologia , Lobo Occipital/patologia , Lobo Parietal/embriologia , Lobo Parietal/patologia , Síndrome de Sturge-Weber/embriologia , Síndrome de Sturge-Weber/genética , Lobo Temporal/embriologia , Lobo Temporal/patologia
20.
Ultrasound Med Biol ; 21(2): 139-42, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7571122

RESUMO

To determine the value of prenatal ultrasonographic scapula measurements for fetal growth and development as an adjunct to assessing in utero development, a prospective study of ultrasonography was conducted in 343 pregnant women with uneventful pregnancies with gestational ages from 16 to 41 weeks, and several biometric measurements were obtained. The relationships of scapula length with gestational age and with biparietal diameter, femur length, abdominal circumference and scapula length were examined. With the ultrasonographic examinations of 343 healthy pregnant women, a nomogram of scapula length measurements estimating gestational age and predicting the biparietal diameter, abdominal circumference, and femur length was generated. Linear relationships were found between the scapula length and the gestational age (R2 = 0.94, p < 0.0001), the biparietal diameter (R2 = 0.94, p < 0.0001), abdominal circumference (R2 = 0.94, p < 0.0001), and the femur length (R2 = 0.95, p < 0.0001). The rate of increase of scapula length was significantly higher before 28 weeks of gestation than in later pregnancy (p < 0.0001). The correlation coefficients between gestational age and scapula length were 0.95 before 28 weeks of gestation and 0.86 in later weeks. These results suggest that scapula length measurement is a valuable parameter for the assessment of fetal growth and development.


Assuntos
Desenvolvimento Embrionário e Fetal/fisiologia , Idade Gestacional , Escápula/embriologia , Ultrassonografia Pré-Natal , Abdome/embriologia , Adulto , Antropometria , Feminino , Fêmur/diagnóstico por imagem , Fêmur/embriologia , Humanos , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/embriologia , Gravidez , Estudos Prospectivos , Valores de Referência , Escápula/diagnóstico por imagem
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