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Article in Chinese | WPRIM | ID: wpr-936287


OBJECTIVE@#To clarify the functional effects of differential expression of ring finger and tryptophan-aspartic acid 2 (RFWD2) on dendritic development and formation of dendritic spines in cerebral cortex neurons of mice.@*METHODS@#Immunofluorescent staining was used to identify the location and global expression profile of RFWD2 in mouse brain and determine the co-localization of RFWD2 with the synaptic proteins in the cortical neurons. We also examined the effects of RFWD2 over-expression (RFWD2-Myc) and RFWD2 knockdown (RFWD2-shRNA) on dendritic development, dendritic spine formation and synaptic function in cultured cortical neurons.@*RESULTS@#RFWD2 is highly expressed in the cerebral cortex and hippocampus of mice, and its expression level was positively correlated with the development of cerebral cortex neurons and dendrites. RFWD2 expression was detected on the presynaptic membrane and postsynaptic membrane of the neurons, and its expression levels were positively correlated with the length, number of branches and complexity of the dendrites. In cultured cortical neurons, RFWD2 overexpression significantly lowered the expressions of the synaptic proteins synaptophysin (P < 0.01) and postsynapic density protein 95 (P < 0.01), while RFWD2 knockdown significantly increased their expressions (both P < 0.05). Compared with the control and RFWD2-overexpressing cells, the neurons with RFWD2 knockdown showed significantly reduced number of dendritic spines (both P < 0.05).@*CONCLUSION@#RFWD2 can regulate the expression of the synaptic proteins, the development of the dendrites, the formation of the dendritic spines and synaptic function in mouse cerebral cortex neurons through ubiquitination of Pea3 family members and c-Jun, which may serve as potential treatment targets for neurological diseases.

Animals , Aspartic Acid/metabolism , Cerebral Cortex , Dendritic Spines/metabolism , Mice , Neurons/metabolism , Synapses , Tryptophan/metabolism
Neuroscience Bulletin ; (6): 47-68, 2022.
Article in English | WPRIM | ID: wpr-929080


Human cortical radial glial cells are primary neural stem cells that give rise to cortical glutaminergic projection pyramidal neurons, glial cells (oligodendrocytes and astrocytes) and olfactory bulb GABAergic interneurons. One of prominent features of the human cortex is enriched with glial cells, but there are major gaps in understanding how these glial cells are generated. Herein, by integrating analysis of published human cortical single-cell RNA-Seq datasets with our immunohistochemistical analyses, we show that around gestational week 18, EGFR-expressing human cortical truncated radial glial cells (tRGs) give rise to basal multipotent intermediate progenitors (bMIPCs) that express EGFR, ASCL1, OLIG2 and OLIG1. These bMIPCs undergo several rounds of mitosis and generate cortical oligodendrocytes, astrocytes and olfactory bulb interneurons. We also characterized molecular features of the cortical tRG. Integration of our findings suggests a general picture of the lineage progression of cortical radial glial cells, a fundamental process of the developing human cerebral cortex.

Astrocytes , Cell Differentiation , Cerebral Cortex , Humans , Neuroglia , Oligodendroglia
Acta Physiologica Sinica ; (6): 145-154, 2022.
Article in Chinese | WPRIM | ID: wpr-927590


The aim of this study was to investigate the harmful effects of acute hypoxia on mouse cerebral cortex and hippocampus and the underlying mechanism. Mouse model of acute hypoxia was constructed by using a sealed glass jar. Laser speckle contrast imaging was used to detect the changes of cerebral blood flow after different time duration of hypoxia. Total superoxide dismutase (T-SOD) and malondialdehyde (MDA) assay kits were used to detect oxidative stress in cerebral cortex and hippocampus. Immunofluorescent staining was used to detect neuroinflammatory response of microglia in the cerebral cortex and hippocampus. One-step TUNEL method was used to detect neuronal apoptosis. The results showed that, compared with non-hypoxia (0 min hypoxia) group, 30 min hypoxia group exhibited decreased cerebral blood flow, higher percentage of CD68+/Iba1+ microglia, and increased neural apoptosis in the cerebral cortex and hippocampus. Compared with 30 min group, 60 min hypoxia group showed significantly decreased cerebral blood flow, increased MDA content in the cortex, as well as greater percentage of CD68+/Iba1+ microglia and neuronal apoptosis in the cerebral cortex and hippocampus. These results suggest that acute hypoxia damages brain tissue in a time-dependent manner and the oxidative stress and neuroinflammation are important mechanisms.

Animals , Cerebral Cortex/metabolism , Hippocampus/metabolism , Hypoxia , Malondialdehyde , Mice , Oxidative Stress , Superoxide Dismutase/pharmacology
Chinese Medical Journal ; (24): 591-597, 2022.
Article in English | WPRIM | ID: wpr-927512


BACKGROUND@#Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans.@*METHODS@#We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient.@*RESULTS@#The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion.@*CONCLUSION@#Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.

Aged , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Arteries , Atrophy , Brain/metabolism , Cerebral Cortex/metabolism , Cerebrovascular Circulation , Constriction, Pathologic/pathology , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Positron-Emission Tomography/methods
Rev. argent. neurocir ; 35(2): 273, jun. 2021.
Article in Spanish | LILACS, BINACIS | ID: biblio-1398834


El reconocimiento de los puntos craneométricos, giros y surcos cerebrales es esencial para la localización de lesio-nes, tanto superficiales como profundas, y programar es-trategias quirúrgicas que impacten en la óptima evolución de nuestros pacientes. Si bien estas destrezas y aptitudes son posibles de adquirir a través del estudio de especíme-nes anatómicos formolizados y de imágenes de resonan-cia magnética, en un escenario quirúrgico real, esto no es tan simple. Al exponer la superficie cerebral, existen va-riaciones anatómicas de los giros y surcos que, a su vez, se encuentran cubiertos de venas y aracnoides con líquido cefalorraquídeo. El desarrollo de los corredores microqui-rúrgicos trans-cisternales, trans-surcales y a través de las fisuras exige el reconocimiento preciso de estas estructu-ras anatómicas

Cerebrum , Cerebral Cortex , Neurosurgery
Arq. neuropsiquiatr ; 79(4): 346-349, Apr. 2021. tab, graf
Article in English | LILACS | ID: biblio-1278379


ABSTRACT The longstanding study of gross anatomy experienced a considerable improvement with the advent of the microscope in the early 17th century. The representative personality of this new era certainly was Marcello Malpighi, seen as "founder of microscopic anatomy". He studied, with a rudimentary compound microscope, numerous tissues and organs of several classes of animals, as well as plants. He described, for the first time, the microscopic structure of the nervous system, identifying in the gray matter of its various levels minute elements he took as "glands". It should be reminded that the concept of "cell" (and "nerve cell") was unknown at his time. Many researchers followed, performing microscopic studies, but without better results, and Malpighi's view was maintained until the beginning of the 19th century, when new histological processing and staining techniques appeared, as well as improved microscopes.

RESUMO O estudo de longa data da anatomia macroscópica experimentou um incremento considerável com o advento do microscópio no início do século 17. A personalidade representativa dessa nova era foi, certamente, Marcello Malpighi, considerado "fundador da anatomia microscópica". Ele estudou, com um microscópio composto rudimentar, numerosos tecidos e órgãos de diversas classes de animais, assim como plantas. Descreveu, pela primeira vez, a estrutura microscópica do sistema nervoso, identificando na substância cinzenta dos vários níveis elementos de minúsculas dimensões, que denominou "glândulas". Deve-se lembrar que o conceito de "célula" (e de "célula nervosa") era desconhecido naquele tempo. Muitos pesquisadores seguiram realizando estudos microscópicos, mas sem resultados melhores, e o entendimento de Malpighi foi mantido até o início do século 19, quando apareceram técnicas histológicas novas de processamento e de coloração, assim como microscópios mais aprimorados.

Animals , History, 17th Century , Nervous System , Neurons , Staining and Labeling , Cerebral Cortex , Gray Matter , Italy
Clin. biomed. res ; 41(3): 220-223, 20210000. tab
Article in English | LILACS | ID: biblio-1342397


Introduction: It is well established that cortical volume are decreased in patients with schizophrenia. One possible explanation is that the increased pro-inflammatory status in schizophrenia is related to volumetric decrease of gray matter. The aim of this study was to correlate interleukin 6 (IL-6) with cortical volume in patients with schizophrenia and controls. Methods: We selected 36 patients with schizophrenia and 35 controls. Interleukin 6 (IL-6) was correlated with cortical volume in patients with schizophrenia and controls. Results: IL-6 was negatively correlated with cortical volume (p = 0.027; rho = −0.370) in patients, but not in controls (p = 0.235). Discussion: Our results are in line with previous studies suggesting that chronic inflammatory activation in patients with schizophrenia could be one plausible mechanism that could contribute for the cortical volumetric decrease often seen in this population. However, this cross-sectional study with a small number of patients does not allow us to establish causal relations. (AU)

Humans , Male , Female , Adult , Middle Aged , Schizophrenia , Cerebral Cortex/physiopathology , Interleukin-6 , Cerebral Cortex , Inflammation
Braz. oral res. (Online) ; 35: e022, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1153612


Abstract This study aimed to determine the mean distances between apexes of the maxillary posterior teeth and the maxillary sinus, between apexes of the mandibular posterior teeth and the mandibular canal, and between the root apexes of all teeth and the adjacent cortical plates. A total of 800 cone-beam computed tomography (CBCT) scans (400 maxillary and 400 mandibular) were obtained from patients indicated for several treatments. The proximity between apexes and anatomical structures, and the relationship between apexes and adjacent cortical plates were assessed together with the risk of over-instrumentation. Paired-sample comparisons were performed by using the paired t-test. The means were compared by ANOVA, Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. a) Most of the apexes classified as A (high-risk proximity) were observed in maxillary first and second molars, in mandibular first and second molars, and in second premolars in relation to near anatomical structures. b) A predominance of class A (86.42%) was noticed in the first premolars, between apexes of maxillary teeth and adjacent cortical plates. c) The distance between apexes of mandibular teeth and buccal cortical plates showed a predominance of medium-risk proximity (B) in all the groups, except the first premolars, with the highest risk (82.22%), and the second molars, with low-risk proximity (C) to distal and mesiobuccal apexes (91.77% and 89.62%). CBCT images are important for endodontic diagnosis and treatment, since many teeth have high risk proximity to near anatomical structures and adjacent cortical plates.

Humans , Maxillary Sinus , Tooth Root/diagnostic imaging , Cerebral Cortex , Cone-Beam Computed Tomography , Molar/diagnostic imaging
Arq. bras. neurocir ; 39(4): 284-288, 15/12/2020.
Article in English | LILACS | ID: biblio-1362329


Discovered in 1865 by Jules Bernard Luys, the subthalamic nucleus is a set of small nuclei located in the diencephalon, inferior to the thalamus and superior to the substantia nigra, that can be visualized in a posterior coronal section. Histologically, it consists of neurons compactly distributed and filled with a large number of blood vessels and sparse myelinated fibers. This review presents an analysis of this anatomical region, considering what is most recent in the literature. Subthalamic neurons are excitatory and use glutamate as the neurotransmitter. In healthy individuals, these neurons are inhibited by nerve cells located in the side globus pallidus. However, if the fibers that make up the afferent circuit are damaged, the neurons become highly excitable, thus causing motor disturbances that can be classified as hyperkinetic, for example ballism and chorea, or hypokinetic, for example Parkinson disease (PD). The advent of deep brain stimulation has given the subthalamic nucleus great visibility. Studies reveal that the stimulation of this nucleus improves themotor symptoms of PD.

Subthalamic Nucleus/anatomy & histology , Subthalamic Nucleus/abnormalities , Subthalamic Nucleus/surgery , Parkinson Disease , Substantia Nigra/anatomy & histology , Cerebral Cortex/anatomy & histology , Corpus Striatum/anatomy & histology , Deep Brain Stimulation/methods , Globus Pallidus/anatomy & histology , Motor Cortex/anatomy & histology
Arq. bras. neurocir ; 39(4): 261-270, 15/12/2020.
Article in English | LILACS | ID: biblio-1362320


In 1909, Korbinian Brodmann described 52 functional brain areas, 43 of them found in the human brain. More than a century later, his devoted functional map was incremented by Glasser et al in 2016, using functional nuclear magnetic resonance imaging techniques to propose the existence of 180 functional areas in each hemisphere, based on their cortical thickness, degree of myelination (cortical myelin content), neuronal interconnection, topographic organization, multitask answers, and assessment in their resting state. This opens a huge possibility, through functional neuroanatomy, to understand a little more about normal brain function and its functional impairment in the presence of a disease.

History, 21st Century , Brain Mapping/history , Cerebellar Cortex/anatomy & histology , Cerebral Cortex/physiology , Cerebral Cortex/injuries , Magnetic Resonance Spectroscopy/methods , Cerebrum/physiology , Mirror Neurons/physiology , Functional Neuroimaging/methods , Neuroanatomy/history
Pesqui. vet. bras ; 40(12): 1077-1087, Dec. 2020. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1155034


The central nervous system is vulnerable to complications caused by diabetes. These complications lead to increased oxidative stress in the brain, resulting in damage to the cerebral cortex, among other regions. Insulin and hypoglycemic agents are still the most widely used treatments. However, current research with an experimental model of diabetes suggests the use of antioxidants, such as melatonin. Thus, we tested the hypothesis that exogenous melatonin may decrease or prevent the effects of diabetes in the frontal cortex of the rat brain. Fifty albino rats were allocated into five groups: GC = rats without diabetes induction, GD = diabetic rats induced by streptozotocin, GDM = streptozotocin-induced and melatonin-treated diabetic rats, GDI = diabetic rats induced by streptozotocin and treated with insulin, GDMI = diabetic rats induced by streptozotocin and treated with melatonin and insulin simultaneously. Diabetes was induced by intraperitoneal administration of streptozotocin (60mg/kg). Insulin (5U/day) was administered subcutaneously and melatonin (10mg/kg) by drinking water; both treatments last days after. We analyzed animals' weight, the cytokines IL-6 and TNF-α, apoptosis, glycogen, and did morphometry and histopathology of the frontal cortex were analyzed. The results showed that the cerebral cortex of the diabetic animals presented axonal degeneration, reduced number of neurons in the cortex, reduced glycogen, increased IL-6 and TNF-α expression, high apoptotic index, and reduced animal weight and the brain. Treatment with melatonin associated or not with insulin prevented such effects. Thus, we conclude that melatonin associated with insulin may be an alternative for avoiding the impact of diabetes in the brain's frontal cortex.(AU)

O sistema nervoso central é vulnerável a complicações originadas pelo diabetes estresse oxidativo no cérebro e resultando em lesões no córtex cerebral, dentre outras regiões. A insulina e hipoglicemiantes ainda são os tratamentos mais utilizados, entretanto, pesquisas atuais com modelo experimental do diabetes sugerem a utilização de antioxidantes como, por exemplo, a melatonina. Assim, testamos a hipótese de que a melatonina exógena pode diminuir ou prevenir os efeitos do diabetes no córtex frontal do cérebro de ratos. Foram utilizados 50 ratos albinos, divididos em 5 grupos: GC = ratos sem indução ao diabetes, GD = ratos induzidos ao diabetes pela estreptozotocina, GDM = ratos induzidos ao diabetes pela estreptozotocina e tratados com melatonina, GDI = ratos induzidos ao diabetes pela estreptozotocina e tratados com insulina, GDMI = ratos induzidos ao diabetes pela estreptozotocina e tratados com melatonina e insulina simultaneamente. O diabetes foi induzido pela administração intraperitoneal de estreptozotocina (60mg/kg). A insulina (5U/dia) foi administrada por via subcutânea e a melatonina (10mg/kg) pela água de beber. Ambos tratamentos foram realizados durante 30 dias após a indução. Foram analisados o peso dos animais, do cerebro, as citocinas IL-6 e TNF-α, apoptose, glicogênio, além da morfometria e histopatologia do córtex frontal. Os resultados mostraram que o córtex cerebral dos animais diabéticos apresentou degeneração axonal, redução do número de neurônios no córtex, redução do glicogênio, aumento da expressão do IL-6 e TNF-α, elevação do índice apoptótico, além da redução do peso dos animais e do cérebro. O tratamento com melatonina associada ou não a insulina preveniu tais efeitos. Assim, concluímos que a melatonina associada ou não a insulina pode ser uma alternativa na prevenção dos efeitos do diabetes no córtex frontal do cérebro.(AU)

Animals , Rats , Immunohistochemistry , Cerebral Cortex , Melatonin , Rats/abnormalities , Apoptosis , Oxidative Stress
Int. j. morphol ; 38(5): 1217-1222, oct. 2020. graf
Article in English | LILACS | ID: biblio-1134428


SUMMARY: Repeated stress is a risk factor for memory impairment and neurological abnormalities in both humans and animals. We sought to investigate the extent of (i) brain tissue injury; (ii) nitrosative and oxidative stress in brain tissue homogenates; (iii) apoptotic and survival biomarkers in brain tissue homogenates; and (iv) immobility and climbing abilities, induced over a period of three weeks by chronic unpredictable stress (CUS). Wistar rats were either left untreated (Control group) or exposed to a variety of unpredictable stressors daily before being sacrificed after 3 weeks (model group). Assessment of depression-like behavior was performed and animals were then culled and harvested brain tissues were stained with basic histological staining and examined under light microscopy. In addition, brain tissue homogenates were prepared and assayed for these parameters; inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), superoxide dismutase (SOD), caspase-3, and B-cell lymphoma 2 (Bcl-2). Histology images showed CUS induced profound damage to the cerebral cortex as demonstrated by severe neuronal damage with shrunken cells, disrupted atrophic nuclei, perineuronal vacuolation and swollen glial cells. CUS also significantly (p<0.05) induced iNOS, MDA, and caspase-3, whereas SOD and Bcl-2 brain tissue levels were inhibited by CUS. In addition, data from the depression-like behavior, forced swimming test showed significant (p<0.05) increase in animal immobility and decrease in climbing ability in the model group of rats. Thus, here we demonstrated a reliable rat model of chronic stress-induced brain injury, which can further be used to investigate beneficial drugs or agents used for a period of three weeks to protect against CUS-induced brain damage.

RESUMEN: El estrés crónico es un factor de riesgo para el deterioro de la memoria y las anomalías neurológicas tanto en humanos como en animales. Intentamos investigar el alcance de lesión del tejido cerebral; (ii) estrés nitrosativo y oxidativo en homogeneizados de tejido cerebral; (iii) biomarcadores apoptóticos y de supervivencia en homogeneizados de tejido cerebral; y (iv) inmovilidad y habilidades de escalada, inducidas durante un período de tres semanas por estrés crónico impredecible (ECI). Se dejaron sin tratamiento (grupo control) ratas Wistar, o se expusieron a una variedad de factores estresantes impredecibles diariamente antes de ser sacrificadas después de 3 semanas (grupo modelo). Se realizó una evaluación del comportamiento similar a la depresión y luego se sacrificaron los animales y se tiñeron los tejidos cerebrales con tinción histológica básica y se examinaron con microscopía óptica. Además, se prepararon homogeneizados de tejido cerebral y se analizaron los siguientes parámetros; óxido nítrico sintasa inducible (iNOS), malondialdehído (MDA), superóxido dismutasa (SOD), caspasa- 3 y linfoma de células B 2 (Bcl-2). Las imágenes histológicas mostraron que el CUS indujo un daño profundo en la corteza cerebral como lo demuestra el daño neuronal severo con células encogidas, núcleos atróficos alterados, vacuolación perineuronal y células gliales inflamadas. ECI también indujo significativamente (p <0,05) iNOS, MDA y caspase-3, mientras que los niveles de tejido cerebral SOD y Bcl-2 fueron inhibidos por ECI. Además, los datos del comportamiento similar a la de- presión, la prueba de natación forzada mostró un aumento significativo (p <0,05) en la inmovilidad animal y una disminución en la capacidad de escalada en el grupo modelo de ratas. Por lo tanto, aquí demostramos un modelo confiable de daño cerebral crónico en rata inducido por el estrés, que se puede utilizar para investigar medicamentos o agentes beneficiosos usados durante un período de tres semanas para proteger el daño cerebral inducido por ECI.

Animals , Male , Rats , Stress, Psychological/complications , Brain Damage, Chronic/pathology , Superoxide Dismutase/analysis , Behavior, Animal , Brain Injuries/metabolism , Biomarkers , Cerebral Cortex , Chronic Disease , Analysis of Variance , Rats, Wistar , Apoptosis , Oxidative Stress , Nitric Oxide Synthase/analysis , Proto-Oncogene Proteins c-bcl-2 , Depression , Disease Models, Animal , Caspase 3/analysis , Nitrosative Stress , Malondialdehyde/analysis
Rev. bras. neurol ; 56(2): 46-52, abr.-jun. 2020. ilus, tab
Article in English | LILACS | ID: biblio-1103037


The nature of memory and the search for its localization have been a subject of interest since Antiquity. After millennia of hypothetical concepts the core memory-related structures finally began to be identified through modern scientifically-based methods at the diencephalic, hippocampal, and neocortical levels. However, there was a clear temporal delay between the finding of these anatomic structures ignoring their function, and their identification related to memory function. Thus, the core structures begun to be identified with a pure anatomical view in the late Middle Ages on, while the memory function related to them was discovered much later, in the late Modern Period.

A natureza da memória e a busca de sua localização tem sido objeto de interesse desde a Antiguidade. Após milênios de conceitos hipotéticos as estruturas centrais relacionadas com a memória finalmente começaram a ser identificadas através de métodos modernos com base científica, nos níveis diencefálico, hipocampal e neocortical. Entretanto, houve um claro retardo temporal entre o achado dessas estruturas anatômicas ignorando sua função e sua identificação relacionada à função da memória. Assim, as estruturas centrais começaram a ser identificadas com uma visão puramente anatômica da Idade Média tardia em diante, enquanto a função da memória relacionada com as mesmas foi descoberta muito mais tarde, no Período Moderno tardio.

Humans , History, 19th Century , History, 20th Century , Cerebral Cortex/anatomy & histology , Cerebrum/anatomy & histology , Memory/physiology , Neocortex , Diencephalon , Hippocampus
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 42(1): 6-13, Jan.-Feb. 2020. tab, graf
Article in English | LILACS | ID: biblio-1055355


Objective: To test the feasibility and to present preliminary results of a neuroimaging protocol to evaluate adolescent depression in a middle-income setting. Methods: We assessed psychotropic medication-free adolescents (age range 14-16 years) with a diagnosis of major depressive disorder (MDD). Participants underwent a comprehensive clinical evaluation and both structural and functional magnetic resonance imaging (fMRI). In this pilot study, a preliminary single-group analysis of resting-state fMRI (rs-fMRI) data was performed, with a focus on the default mode network (DMN), cognitive control network (CCN), and salience network (SN). Results: The sample included 29 adolescents with MDD (mean age 16.01, SD 0.78) who completed the protocol. Only two participants were excluded due to MRI quality issues (head movement), and were not included in the analyses. The scans showed significant connectivity between the medial prefrontal cortex and posterior cingulate cortex (DMN), the ACC and anterior insula (SN), and the lateral prefrontal cortex and dorsal parietal cortex (CCN). Conclusion: We demonstrated the feasibility of implementing a complex neuroimaging protocol in a middle-income country. Further, our preliminary rs-fMRI data revealed patterns of resting-state connectivity consistent with prior research performed in adolescents from high-income countries.

Humans , Male , Adolescent , Magnetic Resonance Imaging/methods , Depressive Disorder, Major/diagnostic imaging , Neuroimaging/methods , Quality Control , Socioeconomic Factors , Brazil , Cerebral Cortex/diagnostic imaging , Feasibility Studies , Surveys and Questionnaires , Reproducibility of Results , Depressive Disorder, Major/physiopathology , Neural Pathways , Neuropsychological Tests
Article in English | WPRIM | ID: wpr-785551


Repetitive transcranial magnetic stimulation (rTMS) has been known to improve the motor function through modulation of excitability in the cerebral cortex. However, most studies with rTMS were limited to post-stroke patients with mild to moderate motor impairments. The effect of rTMS on severe upper-limb motor impairment remains unclear. Therefore, this study investigated the effects of rTMS on the upper extremity function in post-stroke patients with severe upper-limb motor impairment. Subjects were divided into 3 groups, low-, high-frequency rTMS and control group were received stimulation 10 times for 2 weeks. The motor scale of Fugl-Meyer Assessment (FMA) and cortical excitability on the unaffected hemisphere were measured before and after performing 10 rTMS sessions. The motor scale of upper extremity FMA (UE-FMA) and shoulder component of the UE-FMA were significantly improved in both low- and high-frequency rTMS groups. However, no significant improvement was observed in the wrist and hand components. No significant differences were noted in low- and high-frequency rTMS groups. The amplitude of motor evoked potential on the unaffected hemisphere showed a significant decrease in the low- and high-frequency stimulation groups. rTMS may be helpful in improving upper extremity motor function even in post-stroke patients with severe upper-limb motor impairment.

Cerebral Cortex , Evoked Potentials, Motor , Hand , Humans , Recovery of Function , Shoulder , Transcranial Magnetic Stimulation , Upper Extremity , Wrist
Acta cir. bras ; 35(7): e202000705, 2020. tab, graf
Article in English | LILACS | ID: biblio-1130657


Abstract Purpose Studies have demonstrated that star fruit consumption by nephropathic patients triggers severe neurotoxic effects that can lead to convulsions or even death. Brain areas likely susceptible to star fruit poisoning have not been investigated. The objective of the present study was to map possible epileptogenic areas susceptible to star fruit intoxication in nephropathic rats. Methods The study analyzed 25 rats (5 groups). Rats in the experimental group underwent bilateral ureteral obstruction surgery and orogastric gavages with star fruit juice. An electroencephalogram was used to confirm convulsive seizures. Urea and creatinine levels were used to confirm the uremia model. Immunohistochemical analysis was used to map cells with c-Fos protein (c-Fos+ cells) to identify brain areas with increased neuronal activity. Control groups included non-nephropathic and nephropathic rats that did not receive star fruit. Results A statistically significant increase (p<0.01) in c-Fos+ cells was noted in nephropathic animals receiving star fruit juice compared to control groups, in brain areas commonly related to epileptogenic neural circuits including the hippocampus, amygdala, rhinal cortex, anterior cingulate area, piriform area, and medial dorsal thalamus. Conclusion These data corroborate the neurotoxic capacity of star fruit in nephropathic patients.

Humans , Animals , Rats , Brain , Cerebral Cortex , Proto-Oncogene Proteins c-fos/metabolism , Fruit/poisoning , Hippocampus , Kidney Diseases/complications
Int. j. morphol ; 37(4): 1437-1443, Dec. 2019. graf
Article in English | LILACS | ID: biblio-1040150


While various neurodegenerative diseases affect cortical mass differently, finding an optimal and accurate method for measuring the thickness and surface area of cerebral cortex remains a challenging problem due to highly convoluted surface of the cortex. We therefore investigated cortical thickness in a sample of cadaveric specimens at the Discipline of Clinical Anatomy, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, South Africa to provide some clue as to possible variations in the parameters. Following ethical approval, 60 brain samples were uniformly sectioned (5 mm thickness) and eight slices taken from each brain across regions of interest (ROI) prepared and stained by Mulligan's technique. Thickness was measured at selected angles (0º, 45º, 90º, 135º and 180º) for both right and left cerebral hemispheres. Mulligan's stain produced good cortical differentiation and clear images that enabled manual delineation of structures. Cortical thickness ranged from 3 to 5 millimeters across the ROI. Interestingly, there was rightward hemispheric asymmetry of cortical thickness of selective slices at suggested angles which is related to structurally and functionally important brain regions. Moreover, there was no significant correlation between the surface area of superficial cortex and the deep nuclei at the same level. The superficial cortex and deep nuclei are manifested independently in normal aging, neuropsychiatric or developmental disorders. Providing accurate morphometric evaluation of cortical thickness and area based on gross staining of the brain slices could provide qualitative data that may support the study of human cerebral cortex even in disease conditions.

Si bien varias enfermedades neurodegenerativas afectan a la masa cortical de manera diferente, encontrar un método óptimo y preciso para medir el grosor y el área de la superficie de la corteza cerebral sigue siendo un problema difícil debido a la superficie altamente enrevesada de la corteza. Por lo tanto, investigamos el grosor cortical en una muestra de cadáveres del Departamento de Anatomía Clínica de la Facultad de Medicina Nelson R. Mandela de la Universidad de KwaZulu-Natal, Sudáfrica, para proporcionar alguna pista sobre posibles variaciones en dichos parámetros. Después de la aprobación ética, 60 muestras de cerebro se seccionaron uniformemente (5 mm de grosor) y se tomaron ocho cortes de cada cerebro en regiones de interés (ROI) preparadas y teñidas con la técnica de Mulligan. El espesor se midió en los ángulos seleccionados (0º, 45º, 90º, 135º y 180º) para los hemisferios cerebrales derecho e izquierdo. La tinción de Mulligan produjo una buena diferenciación cortical e imágenes claras que permitieron la delineación manual de las estructuras. El grosor cortical osciló entre 3 y 5 milímetros a través del ROI. Curiosamente, hubo una asimetría hemisférica hacia la derecha del grosor cortical de los cortes en ángulos sugeridos que se relacionan con regiones cerebrales estructural y funcionalmente importantes. Además, no hubo una correlación significativa entre el área de la superficial de la corteza superficial y los núcleos profundos en el mismo nivel. La corteza superficial y los núcleos profundos se manifiestan de manera independiente en el envejecimiento normal, en los trastornos neuropsiquiátricos o del desarrollo. Realizar una evaluación morfométrica precisa del grosorcortical y el área basada en la tinción macroscópica de los cortes del cerebro, podría proporcionar datos cualitativos que puedan respaldar el estudio de la corteza cerebral humana incluso en condiciones de enfermedad.

Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Staining and Labeling/methods , Brain/anatomy & histology , Cadaver , Cerebral Cortex/anatomy & histology , Gray Matter/anatomy & histology
Pensam. psicol ; 17(1): 19-32, ene.-jun. 2019. tab, graf
Article in Spanish | LILACS | ID: biblio-1020099


Resumen Objetivo. El ejercicio físico (EF) se relaciona con estructuras cerebrales y funcionamiento cognitivo; sin embargo, se desconocen indicadores de frecuencia, duración e intensidad del EF asociados a procesos neuropsicológicos. Estudiar la relación y las posibles diferencias entre las funciones ejecutivas (FE) y los indicadores del EF (frecuencia, duración y tiempo que lleva practicando EF). Método. Se seleccionó una muestra intencional de treinta sujetos físicamente activos, pareados por sexo ( Medad = 22.9, DE = 8.5). Se aplicó la totalidad de la Batería de Funciones Ejecutivas y Lóbulos Frontales (Banfe). Resultados. El desempeño neuropsicológico se relacionó con la frecuencia del EF en tareas que evalúan capacidades de control inhibitorio, seguimiento de límites y normas, memoria de trabajo visoespacial y anticipación de acciones de orden progresivo y regresivo. La duración y el tiempo de entrenamiento presentaron relación con la planeación, respeto por los límites y la inhibición. Aquellos participantes que se ejercitan más de seis veces por semana presentaron mejor desempeño en los aciertos y menor número de errores en el control inhibitorio. No se diferencia el desempeño neuropsicológico en función a indicadores y tipo de EF. Conclusión. Se confirma la hipótesis acerca de que el EF se asocia con procesos neuropsicológicos. Se abren posibles implicaciones científicas, educativas y clínicas.

Abstract Objective. Physical Exercise (PE) is related to cerebral structures and cognitive functioning. Nevertheless, PE indicators of frequency, duration, intensity and neuropsychological processes are unknown. The goal was to study the relationship and the possible differences between executive functions (EF) and PE indicators (frequency, duration and time PE is being practiced). Method. We selected an intentional sample of thirty physically active subjects, paired by sex (Age mean = 22.9, SD = 8.5). We used the whole assessment of Executive Functions and Frontal Lobes Battery (BANFE). Results. Neuropsychological performance was related to the PE frequency in tasks that assess inhibitory control, monitoring of limits and rules, visual-spatial working memory and predicting in reversal and progressive order actions. The duration and time of training showed relationship with planning and inhibition control. The participants who exercise more than six times a week showed a better performance and less number of inhibition control mistakes. Neuropsychological performance dependent on indicators and type of PE are not distinguished. Conclusion. The hypothesis is confirmed. There is a relationship between PE and neuropsychological processes with possible scientific, educational and clinical implications.

Resumo Escopo. O Exercício Físico (EF) está relacionado com estruturas cerebrais e funcionamento cognitivo. Porém são desconhecidos indicadores de frequência, duração e intensidade de EF associados aos processos neuropsicológicos. Estudar a relação e as possíveis diferenças entre as Funções Executivas (FE) e indicadores do EF (Frequência, Duração e Tempo que leva praticando EF). Metodologia. Foi selecionada uma amostra intencional de trinta sujeitos ativamente físicos, pareados por sexo ( Midade= 22.9, DE= 8.5). Foi aplicada a totalidade da Bateria de Funções Executivas e Lóbulos Frontais (BANFE). Resultados. O desempenho neuropsicológico esteve relacionado com a Frequência do EF em tarefas que avaliam capacidades de controle inibitório, seguimento de limites e normas, memória de trabalho vioespacial, e antecipação de ações de ordem progressiva e regressiva. A duração e o tempo de treinamento apresentaram relação com o planejamento, respeito pelos limites e a inibição. Aqueles participantes que se exercitaram mais de seis vezes por semana apresentaram melhor desempenho nos sucessos e menor número de erros no controle inibitório. Não houve diferença no desempenho neuropsicológico em função a indicadores e tipo de EF. Conclusão. Foi confirmada a hipótese de que o EF está associado com processos neuropsicológicos. Foram abertas possíveis implicações científicas, educativas e clínicas.

Humans , Young Adult , Exercise , Neuropsychology , Cerebral Cortex , Cognition
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 41(2): 101-111, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-990827


Objective: To compare results of positron emission tomography (PET) with carbon-11-labeled Pittsburgh compound B (11C-PIB) obtained with cerebellar or global brain uptake for voxel intensity normalization, describe the cortical sites with highest tracer uptake in subjects with mild Alzheimer's disease (AD), and explore possible group differences in 11C-PIB binding to white matter. Methods: 11C-PIB PET scans were acquired from subjects with AD (n=17) and healthy elderly controls (n=19). Voxel-based analysis was performed with statistical parametric mapping (SPM). Results: Cerebellar normalization showed higher 11C-PIB uptake in the AD group relative to controls throughout the cerebral cortex, involving the lateral temporal, orbitofrontal, and superior parietal cortices. With global uptake normalization, greatest cortical binding was detected in the orbitofrontal cortex; decreased 11C-PIB uptake in white matter was found in the posterior hippocampal region, corpus callosum, pons, and internal capsule. Conclusion: The present case-control voxelwise 11C-PIB PET comparison highlighted the regional distribution of amyloid deposition in the cerebral cortex of mildly demented AD patients. Tracer uptake was highest in the orbitofrontal cortex. Decreased 11C-PIB uptake in white-matter regions in this patient population may be a marker of white-matter damage in AD.

Humans , Male , Female , Aged , Aged, 80 and over , Carbon Radioisotopes , Cerebral Cortex/diagnostic imaging , Positron-Emission Tomography/methods , Alzheimer Disease/diagnostic imaging , White Matter/diagnostic imaging , Severity of Illness Index , Case-Control Studies