RESUMO
Sensory development is a complex process that can influence physiological and pathological factors. In laterally-eyed mammals, monocular enucleation (ME) during development and the subsequent lack of external sensory stimuli can result in permanent morphological and physiological changes. Malnutrition, especially in early life, also can cause permanent morphofunctional changes due to inadequate nutrient intake in both hemispheres. This study investigated the effects of early (postnatal day 7) ME and malnutrition during the suckling period on cortical excitability in adulthood (110-140 days of life). For this, we compared the speed propagation of cortical spreading depression in the occipital and parietal cortex of malnourished and well-nourished adult rats, previously suckled small-sized litters with three pups (L3/dam) medium-sized litters with six pups (L6/dam), and large-sized litters with twelve pups (L12/dam). The CSD velocity was augmented by the ME in the contralateral side of the removed eye in the parietal and occipital cortex. These findings suggest that visual sensory input deprivation is associated with permanent functional changes in the visual pathways, which can alter cortical excitability and lead to modifications in CSD propagation.
Assuntos
Depressão Alastrante da Atividade Elétrica Cortical , Enucleação Ocular , Desnutrição , Ratos Wistar , Animais , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Desnutrição/fisiopatologia , Desnutrição/complicações , Ratos , Masculino , Feminino , Animais Recém-Nascidos , Lobo Occipital/fisiopatologia , Lobo Parietal/fisiopatologiaRESUMO
Moderate reduction of dietary protein (from 25% to 8% casein) in pregnant rats, calorically compensated by carbohydrates, gives rise to 'hidden prenatal malnutrition' (HPM) in the offspring since it does not alter body and brain weights of pups at birth. However, this dietary treatment leads to decreased ß-adrenoceptor signaling and brain derived neurotrophic factor (BDNF) levels in the pup' brain, altogether with defective cortical long-term potentiation (LTP) and lowered visuospatial memory performance. Since early postnatal environmental enrichment (EE) has been shown to exert plastic effects on the developing brain and neuroprotection both on cognition and on structural properties of the neocortex, in the present study we addressed the question of whether early postnatal EE during the lactation period could exert compensatory changes in the expression of ®-adrenergic receptors and BDNF in the neocortex of HPM rats, and if these effects are associated with an improvement or even a restore of both neocortical LTP in vivo and cognitive performance induced by HPM. The results obtained show that EE restored ß-adrenoceptor density, BDNF expression and the ability to support LTP at prefrontal and occipital cortices of HPM rats. Besides, EE improved learning performance in visuospatial and operant conditioning tasks. The latter support the notion that adequate maternal protein nutrition during pregnancy is required for proper brain development and function. Further, the results highlight the role of environmental enrichment during early postnatal life in increasing later brain plasticity and exerting neuroprotection against brain deficits induced by prenatal malnutrition.
Assuntos
Córtex Cerebral/fisiologia , Aprendizagem/fisiologia , Cuidado Pós-Natal/métodos , Animais , Animais Recém-Nascidos/psicologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cognição/fisiologia , Feminino , Potenciação de Longa Duração/fisiologia , Masculino , Desnutrição/fisiopatologia , Memória/fisiologia , Neocórtex/fisiopatologia , Plasticidade Neuronal/fisiologia , Lobo Occipital/fisiopatologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta/metabolismoRESUMO
OBJECTIVE: Generalized anxiety disorder (GAD) in older adults is associated with persistent deficits in emotion reactivity (ER) and regulation, yet the neural basis of these deficits has not been explored. This study focuses on the neural basis of ER deficits in late-life GAD and the association with cerebrovascular burden. METHODS: Twenty elderly nonanxious participants and 17 late-life GAD participants were included. The faces-shapes functional magnetic resonance imaging task was used to assess ER; the Hamilton Anxiety Rating Scale and the Penn State Worry Questionnaire to measure global anxiety and worry, respectively; linear regression models to examine the association between ER and global anxiety severity and between ER and worry severity; and mediation analysis to explore the effect of ER on the relationship between global anxiety/worry severity and cerebrovascular burden. RESULTS: A positive association was found between ER and global anxiety in the left parahippocampus, left and right precuneus, and right superior occipital gyrus. A negative association was found between ER and worry severity in the left and right precuneus. The association between cerebrovascular burden and anxiety/worry severity was indirectly mediated by increased ER in limbic and paralimbic areas and by decreased ER in prefrontal regulatory regions. CONCLUSION: These results indicate that ER is associated with different neural activation patterns for worry and global anxiety and that ER-related functional connectivity indirectly mediates the relationship between cerebrovascular burden and late-life GAD. This latter result supports a yet-unexplored cerebrovascular pathway involved in the pathophysiology of late-life anxiety.
Assuntos
Transtornos de Ansiedade/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos de Início Tardio/diagnóstico por imagem , Idoso , Transtornos de Ansiedade/fisiopatologia , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Transtornos Cerebrovasculares/fisiopatologia , Emoções , Feminino , Neuroimagem Funcional , Humanos , Processamento de Imagem Assistida por Computador , Transtornos de Início Tardio/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/fisiopatologia , Giro Para-Hipocampal/diagnóstico por imagem , Giro Para-Hipocampal/fisiopatologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiopatologia , Autocontrole , Índice de Gravidade de DoençaAssuntos
Humanos , Masculino , Feminino , Lobo Occipital/fisiologia , Lobo Occipital/fisiopatologia , AgnosiaRESUMO
The current study describes the case of a woman with symptomatic epilepsy due to brain cysticercosis acquired during childhood. During her adolescence, she developed seizures characterized by metamorphopsia, hallucinations of autobiographic memory and, finally, asomatognosia. Magnetic brain imaging showed a calcified lesion in the right occipitotemporal cortex, and positron emission tomography imaging confirmed the presence of interictal hypometabolism in two regions: the right parietal cortex and the right lateral and posterior temporal cortex. We discuss the link between these brain areas and the symptoms described under the concepts of epileptogenic lesion, epileptogenic zone, functional deficit zone, and symptomatogenic zone.
Assuntos
Imagem Corporal , Encéfalo/fisiopatologia , Epilepsia/complicações , Alucinações/fisiopatologia , Memória Episódica , Neurocisticercose/complicações , Adulto , Encéfalo/metabolismo , Encéfalo/patologia , Epilepsia/etiologia , Feminino , Alucinações/etiologia , Alucinações/metabolismo , Alucinações/patologia , Humanos , Imageamento por Ressonância Magnética , Lobo Occipital/metabolismo , Lobo Occipital/patologia , Lobo Occipital/fisiopatologia , Lobo Parietal/metabolismo , Lobo Parietal/patologia , Lobo Parietal/fisiopatologia , Tomografia por Emissão de Pósitrons , Reconhecimento Psicológico/fisiologia , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Lobo Temporal/fisiopatologiaRESUMO
Retinoic acid induced 1 (RAI1) is a protein of uncertain mechanism of action which nevertheless has been the focus of attention because it is a major contributing factor in several human developmental disorders including Smith-Magenis and Potocki-Lupski syndromes. Further, RAI1 may be linked to adult neural disorders with developmental origins such as schizophrenia and autism. The protein has been extensively examined in the rodent but very little is known about its distribution in the human central nervous system. This study demonstrated the presence of RAI1 transcript in multiple regions of the human brain. The cellular expression of RAI1 protein in the human brain was found to be similar to that described in the mouse, with high levels in neurons, but not glia, of the dentate gyrus and cornus ammonis of the hippocampus. In the cerebellum, a second region of high expression, RAI1 was present in Purkinje cells, but not granule cells. RAI1 was also found in neurons of the occipital cortex. The expression of this retinoic acid-induced protein matched well in the hippocampus with expression of the retinoic acid receptors. The subcellular distribution of human neuronal RAI1 indicated its presence in both cytoplasm and nucleus. Overall, human RAI1 protein was found to be a highly expressed neuronal protein whose distribution matches well with its role in cognitive and motor skills.
Assuntos
Cerebelo/química , Hipocampo/química , Doenças do Sistema Nervoso/metabolismo , Neurônios/química , Lobo Occipital/química , Fatores de Transcrição/análise , Cerebelo/patologia , Cognição , Regulação da Expressão Gênica , Hipocampo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Destreza Motora , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/fisiopatologia , Doenças do Sistema Nervoso/psicologia , Lobo Occipital/fisiopatologia , Células de Purkinje/química , RNA Mensageiro/análise , Transdução de Sinais , Transativadores , Fatores de Transcrição/genéticaRESUMO
Gastaut type idiopathic childhood occipital epilepsy is an uncommon epileptic syndrome characterised by frequent seizures, most commonly presenting as elementary visual hallucinations or blindness. Other occipital (non-visual) symptoms may also occur. Interictal EEG typically shows occipital paroxysms, often with fixation-off sensitivity. Ictal EEG is usually characterised by interruption by paroxysms and sudden appearance of low-voltage, occipital, fast rhythm and/or spikes. Despite well described clinical and EEG patterns, to our knowledge, there are very few reports in the literature with video-EEG recording of either seizure semiology or fixation-off phenomena. We present a video-EEG recording of a 12-year-old girl with Gastaut type epilepsy, illustrating the interictal and ictal aspects of this syndrome. Our aim was to demonstrate the clinical and neurophysiological pattern of a typical seizure of Gastaut type epilepsy, as well as the fixation-off phenomena, in order to further clarify the typical presentation of this syndrome. [Published with video sequences].
Assuntos
Epilepsias Parciais/fisiopatologia , Lobo Occipital/fisiopatologia , Criança , Eletroencefalografia , Feminino , HumanosRESUMO
Moderate reduction in the protein content of the mother's diet calorically compensated by carbohydrates (the so-called "hidden" prenatal malnutrition) leads to increased neocortical expression of the α(2C)-adrenoceptor subtype, together with decreased cortical release of noradrenaline and impaired long-term potentiation (LTP) and visuospatial memory performance during the rat postnatal life. In order to study whether overexpression of the α(2C)-adrenoceptor subtype is causally related to the decreased indices of neocortical plasticity found in prenatally malnourished rats, we evaluated the effect of intracortical (occipital cortex) administration of an antisense oligodeoxynucleotide (ODN) raised against the α(2C)-adrenoceptor mRNA on the LTP elicited in vivo in the occipital cortex of hidden prenatally malnourished rats. In addition, we compare the effect of the antisense ODN to that produced by systemical administration of the subtype-nonselective α(2)-adrenoceptor antagonist atipamezole. Prenatal protein malnutrition led to impaired occipital cortex LTP together with increased expression of α(2C)-adrenoceptors (about twice Bmax) in the same cortical region. [(3)H]-rauwolscine binding assay showed that a 7-day intracortical antisense ODN treatment in the malnourished rats resulted in 50% knockdown of α(2C)-adrenoceptor expression and, in addition, completely rescued the ability of the occipital cortex to develop and maintain long-term potentiation. Atipamezole (0.3 mg/kg i.p.) also led to full recovery of neocortical LTP in malnourished rats. The present results argue in favor of our original hypothesis that the deleterious effect of prenatal malnutrition on neocortical plasticity in the adult progeny is in part consequence of increased neocortical α(2C)-adrenoceptor expression. This receptor subtype is known to be involved in the presynaptic control of noradrenaline release from central neurons, a neurotransmitter that critically influences LTP and memory formation.
Assuntos
Potenciação de Longa Duração/fisiologia , Desnutrição/metabolismo , Lobo Occipital/metabolismo , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Fenômenos Fisiológicos da Nutrição Pré-Natal/fisiologia , Receptores Adrenérgicos alfa 2/genética , Animais , Feminino , Imidazóis/farmacologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Desnutrição/genética , Desnutrição/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Lobo Occipital/efeitos dos fármacos , Lobo Occipital/fisiopatologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos alfa 2/metabolismoRESUMO
This study intended to investigate the clinical and electroencephalographic benign occipital epilepsy of childhood (BOEC) characteristics in a population sample of patients from two tertiary Brazilian hospitals. We analyzed retrospectively 4912 electroencephalograms (EEGs) records, and the included patients were submitted to a new clinical and EEG evaluation. Were included 12 (0.92%) patients; 4 (33.3%) with criteria for early BOEC; 6 (50%) for late form and 2 (16.7%) with superimposed early and late onset forms. After new investigation, 2 (16.7%) had normal EEG; 4 (33.3%) had paroxysms over the occipital region; 3 (25%) over the temporal posterior regions and 3 (25%) over the posterior regions. Sharp waves were the predominant change, occurring in 8 (66.6%); spike and slow wave complexes in 1 (8.3%) and sharp and slow wave complexes in 1 (8.3%). Vomiting, headache and visual hallucinations were the most common ictal manifestations, presented in 100% of patients with superimposed forms. Vomiting were absent in the late form and headache was present in all forms of BOEC.
Assuntos
Epilepsia/fisiopatologia , Lobo Occipital/fisiopatologia , Brasil , Criança , Pré-Escolar , Eletroencefalografia , Epilepsia/diagnóstico , Feminino , Humanos , Masculino , Estudos RetrospectivosRESUMO
This study intended to investigate the clinical and electroencephalographic benign occipital epilepsy of childhood (BOEC) characteristics in a population sample of patients from two tertiary Brazilian hospitals. We analyzed retrospectively 4912 electroencephalograms (EEGs) records, and the included patients were submitted to a new clinical and EEG evaluation. Were included 12 (0.92 percent) patients; 4 (33.3 percent) with criteria for early BOEC; 6 (50 percent) for late form and 2 (16.7 percent) with superimposed early and late onset forms. After new investigation, 2 (16.7 percent) had normal EEG; 4 (33.3 percent) had paroxysms over the occipital region; 3 (25 percent) over the temporal posterior regions and 3 (25 percent) over the posterior regions. Sharp waves were the predominant change, occurring in 8 (66.6 percent); spike and slow wave complexes in 1 (8.3 percent) and sharp and slow wave complexes in 1 (8.3 percent). Vomiting, headache and visual hallucinations were the most common ictal manifestations, presented in 100 percent of patients with superimposed forms. Vomiting were absent in the late form and headache was present in all forms of BOEC.
Este estudo teve como objetivo investigar as características clínicas e eletrencefalográficas da epilepsia occipital benigna da infância (EOBI) em uma amostra populacional de pacientes de dois hospitais terciários brasileiros. Foram analisados retrospectivamente 4912 registros de eletrencefalograma (EEG). Os pacientes incluídos foram submetidos a nova avaliação clínica e eletrencefalográfica. Foram incluídos 12 (0,92 por cento) pacientes; 4 (33,3 por cento), com critérios para EOBI de início precoce; 6 (50 por cento) para a forma tardia e 2 (16,7 por cento), com superimposição de formas de início precoce e tardio. Após nova investigação, 2 (16,7 por cento) apresentaram EEG normal; 4 (33,3 por cento) paroxismos sobre a região occipital; 3 (25 por cento) sobre a região temporal posterior e 3 (25 por cento) sobre as regiões posteriores. Ondas agudas foram a alteração predominante, ocorrendo em 8 (66,6 por cento); complexos espícula e onda lenta em 1 (8,3 por cento) e complexos onda aguda e onda lenta em 1 (8,3 por cento). Vômitos, cefaléia e alucinações visuais foram as manifestações ictais mais comuns, estando presentes em 100 por cento dos pacientes com formas superimpostas de EOBI. Vômitos não foram relatados na forma tardia e cefaléia esteve presente em todas as formas de EOBI.