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1.
J Comp Neurol ; 529(16): 3676-3708, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34259349

RESUMO

In the current study, we examined the number, distribution, and aspects of the neurochemical identities of infracortical white matter neurons, also termed white matter interstitial cells (WMICs), in the brains of a southern lesser galago (Galago moholi), a black-capped squirrel monkey (Saimiri boliviensis boliviensis), and a crested macaque (Macaca nigra). Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most dense close to inner cortical border, decreasing in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed estimates of approximately 1.1, 10.8, and 37.7 million WMICs within the infracortical white matter of the galago, squirrel monkey, and crested macaque, respectively. The total numbers of WMICs form a distinct negative allometric relationship with brain mass and white matter volume when examined in a larger sample of primates where similar measures have been obtained. In all three primates studied, the highest densities of WMICs were in the white matter of the frontal lobe, with the occipital lobe having the lowest. Immunostaining revealed significant subpopulations of WMICs containing neuronal nitric oxide synthase (nNOS) and calretinin, with very few WMICs containing parvalbumin, and none containing calbindin. The nNOS and calretinin immunopositive WMICs represent approximately 21% of the total WMIC population; however, variances in the proportions of these neurochemical phenotypes were noted. Our results indicate that both the squirrel monkey and crested macaque might be informative animal models for the study of WMICs in neurodegenerative and psychiatric disorders in humans.


Assuntos
Química Encefálica/fisiologia , Encéfalo/citologia , Galagidae/fisiologia , Macaca/fisiologia , Neurônios/ultraestrutura , Saimiri/fisiologia , Substância Branca/citologia , Animais , Calbindina 2/metabolismo , Calbindinas/metabolismo , Contagem de Células , Lobo Frontal/citologia , Lobo Frontal/ultraestrutura , Imuno-Histoquímica , Masculino , Neurônios/química , Óxido Nítrico Sintase Tipo I/metabolismo , Lobo Occipital/citologia , Lobo Occipital/ultraestrutura , Parvalbuminas/metabolismo , Especificidade da Espécie , Substância Branca/química
2.
Musculoskelet Sci Pract ; 45: 102075, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31662275

RESUMO

BACKGROUND: Evidence suggests that suboccipital musculature plays an important role in headache. Proper therapeutic approaches targeting this muscle are needed. OBJECTIVE: Our aim was to determine with fresh cadavers and ultrasound imaging if a solid needle is able to properly penetrate the obliquus capitis inferior muscle during the application of dry needling. DESIGN: A cadaveric and human descriptive study. METHODS: Needling insertion and ultrasound imaging of the obliquus capitis inferior muscle was conducted on 10 pain-free healthy subjects and 5 fresh cadavers. Needling insertion was performed using a 40 mm needle inserted midway between the spinous process of C2 and transverse process of C1. The needle was advanced from a posterior to anterior direction into the obliquus capitis inferior muscle with an inferior-lateral angle to reach the lamina of C2. For the cadaveric study, the obliquus capitis inferior placement was verified by resecting the superficial upper trapezius, splenius capitis, and semispinalis capitis muscles. For ultrasographic study, a linear transducer was aligned with the long axis of the obliquus capitis inferior muscle after needle insertion. RESULTS: Both the cadaveric and ultrasonic studies showed that the needle penetrated the obliquus capitis inferior muscle during its insertion and that the tip of the needle rested against C2 laminae, thereby reaching the targeted muscle. CONCLUSION: This anatomical and ultrasound imaging study supports the assertion that needling insertion of the obliquus capitis inferior muscle can be properly conducted by an experienced clinician.


Assuntos
Terapia por Acupuntura/métodos , Região Lombossacral/diagnóstico por imagem , Região Lombossacral/inervação , Lobo Occipital/ultraestrutura , Músculos Paraespinais/ultraestrutura , Músculos Superficiais do Dorso/ultraestrutura , Cefaleia do Tipo Tensional/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Lobo Occipital/diagnóstico por imagem , Músculos Paraespinais/diagnóstico por imagem , Músculos Superficiais do Dorso/diagnóstico por imagem , Ultrassonografia
3.
Eur. j. anat ; 20(1): 31-36, ene. 2016. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-151789

RESUMO

Understanding the functional role of the cervical muscles is important for the effective diagnosis and treatment of cervical disorders. The suboccipital muscles are targets for treatment in whiplash and chronic headache, although their function remains unclear. There are no data on suboccipital muscle fiber type composition to facilitate an understanding of their function. Suboccipital muscles (n=95; rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, obliquus capitis inferior) were dissected bilaterally from 12 cadavers (6 male; mean age 81 years). Immunohistochemistry was used to identify type I/II muscle fibers. Fibers were counted using stereology (random systematic sampling) and data analyzed (descriptive statistics, ANOVA, paired and independent t-tests) to examine differences between muscles, sex and laterality (p<0.05). Mean [SD] type I fiber proportion overall was 62.3% [10.9]; rectus capitis posterior minor had the smallest proportion of type I fibers (58.8% [9.5]), obliquus capitis inferior the largest (69.2% [10.5]). There were no significant differences overall between muscles or sides. There was a significant difference between sexes overall when data from the four muscles were pooled (p=0.027), but no difference when muscles were compared separately. Individual suboccipital muscles showed similar type I/II fiber type proportions, suggesting homogenous function for muscles in this group. Fiber type composition indicated high levels of both postural and phasic activity. Conservative management of cervical disorders involving the suboccipital muscles (e.g. exercise therapy) should consider the homogenous function of this muscle group, and include rehabilitation promoting both postural and phasic function


No disponible


Assuntos
Humanos , Fibras Musculares Esqueléticas/ultraestrutura , Lobo Occipital/ultraestrutura , Imuno-Histoquímica/métodos , Dissecação/métodos , Cadáver
4.
Depress Anxiety ; 31(12): 1007-17, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25450164

RESUMO

BACKGROUND: The aims of this study were to determine white matter (WM) microstructure abnormalities in obsessive-compulsive disorder (OCD) using diffusion tensor imaging, and to investigate whether these abnormalities differ according to OCD symptom dimensions. METHODS: Sixty-three child and adolescent OCD patients (11-18 years old) and 37 healthy subjects matched for gender, age, and estimated intelligence quotient were assessed by means of psychopathology scales and diffusion tensor magnetic resonance imaging. RESULTS: Compared with healthy controls OCD patients showed a significant decrease (t = 3.79, P = .049 FDR-corrected) in fractional anisotropy (FA) in the anterior region of the corpus callosum (CC). In addition, mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values were significantly increased in OCD compared with controls in the CC and in several WM regions of the cingulate, frontal and occipital lobes, basal ganglia, cerebellum, and pons. Compared with healthy controls, OCD patients presenting the harm/checking dimension showed decreased FA in the CC and in the left anterior cingulate gyrus and caudate nucleus, whereas patients with a predominant contamination/washing symptom dimension presented significantly decreased FA in the left midbrain, lentiform nucleus, insula, and thalamus, and increased MD, AD, and RD in both the anterior lobes of cerebellum and in the pons. CONCLUSIONS: The findings suggest WM abnormalities at the microstructural level in the pathogenesis of OCD. Moreover, WM abnormalities in OCD may vary according to the specific OCD symptom dimensions, thus indicating the clinical heterogeneity of the condition.


Assuntos
Encéfalo/ultraestrutura , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Transtorno Obsessivo-Compulsivo/diagnóstico , Transtorno Obsessivo-Compulsivo/psicologia , Adolescente , Anisotropia , Gânglios da Base/ultraestrutura , Encéfalo/anormalidades , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Cerebelo/diagnóstico por imagem , Criança , Corpo Caloso/ultraestrutura , Corpo Estriado/ultraestrutura , Imagem de Tensor de Difusão/métodos , Feminino , Giro do Cíngulo/ultraestrutura , Humanos , Masculino , Transtorno Obsessivo-Compulsivo/patologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Lobo Occipital/ultraestrutura , Ultrassonografia
5.
J Neurosci ; 30(29): 9670-82, 2010 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-20660250

RESUMO

Monocular lid closure (MC) causes a profound shift in the ocular dominance (OD) of neurons in primary visual cortex (V1). Anatomical studies in both cat and mouse V1 suggest that large-scale structural rearrangements of eye-specific thalamocortical (TC) axons in response to MC occur much more slowly than the shift in OD. Consequently, there has been considerable debate as to whether the plasticity of TC synapses, which transmit competing visual information from each eye to V1, contributes to the early functional consequences of MC or is simply a feature of long-term deprivation. Here, we used quantitative immuno-electron microscopy to examine the possibility that alterations of TC synapses occur rapidly enough to impact OD after brief MC. The effect of short-term deprivation on TC synaptic structure was examined in male C57BL/6 mice that underwent 3 and 7 d of MC or monocular retinal inactivation (MI) with tetrodotoxin. The data show that 3 d of MC is sufficient to induce substantial remodeling of TC synapses. In contrast, 3 d of MI, which alters TC activity but does not shift OD, does not significantly affect the structure of TC synapses. Our results support the hypothesis that the rapid plasticity of TC synapses is a key step in the sequence of events that shift OD in visual cortex.


Assuntos
Plasticidade Neuronal/fisiologia , Regeneração/fisiologia , Sinapses/fisiologia , Sinapses/ultraestrutura , Tálamo/fisiologia , Córtex Visual/fisiologia , Animais , Biomarcadores/análise , Potenciais Evocados Visuais , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Neurônios , Lobo Occipital/química , Lobo Occipital/citologia , Lobo Occipital/ultraestrutura , Sinapses/química , Proteína Vesicular 2 de Transporte de Glutamato/análise , Vias Visuais/fisiologia
6.
J Comp Neurol ; 516(4): 264-76, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19634180

RESUMO

The connection between the dorsal lateral geniculate nucleus (dLGN) and area 17 of the cat is a classical model for studying thalamocortical relations. We investigated the proportion of asymmetric synapses in layer 4 of area 17 of cats formed by axons of the dLGN, because this is an important morphological parameter in understanding the impact of dLGN axons on their target neurons. Although the present consensus is that this proportion is small, the exact percentage remains in doubt. Most previous work estimated that the thalamus contributes less than 10% of excitatory synapses in layer 4, but one estimate was as high as 28%. Two issues contribute to these widely different estimates, one being the tracers used, the other being the use of biased stereological approaches. We have addressed both of these issues. Thalamic axons were labeled in vivo by injections of biotinylated dextran amine into the A lamina of the dLGN of anesthetized cats. After processing, the brain was cut serially and prepared for light and electron microscopy. The density of asymmetric synapses in the neuropil and the density of synapses formed by labeled dLGN boutons were measured by using an unbiased sampling method called the physical disector. Our counts indicate that, in the fixed cat brain, there are 5.9 x 10(8) +/- 0.9 x 10(8) asymmetric synapses per cubic millimeter of layer 4 in area 17, and the dLGN input provides only 6% of all asymmetric synapses in layer 4. The vast majority of synapses of layer 4 probably originate from other neurons in area 17.


Assuntos
Axônios/ultraestrutura , Corpos Geniculados/ultraestrutura , Vias Neurais/ultraestrutura , Lobo Occipital/ultraestrutura , Sinapses/ultraestrutura , Animais , Gatos , Feminino , Masculino
7.
Neuroscience ; 148(4): 876-92, 2007 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-17719182

RESUMO

Cell-cell communication in astroglial syncytia is mediated by intracellular Ca(2+) ([Ca(2+)](i)) responses elicited by extracellular signaling molecules as well as by diverse physical and chemical stimuli. Despite the evidence that astrocytic swelling promotes [Ca(2+)](i) elevation through Ca(2+) influx, the molecular identity of the channel protein underlying this response is still elusive. Here we report that primary cultured cortical astrocytes express the transient receptor potential vanilloid-related channel 4 (TRPV 4), a Ca(2+)-permeable cation channel gated by a variety of stimuli, including cell swelling. Immunoblot and confocal microscopy analyses confirmed the presence of the channel protein and its localization in the plasma membrane. TRPV4 was functional because the selective TRPV4 agonist 4-alpha-phorbol 12,13-didecanoate (4alphaPDD) activated an outwardly rectifying cation current with biophysical and pharmacological properties that overlapped those of recombinant human TRPV4 expressed in COS cells. Moreover, 4alphaPDD and hypotonic challenge promoted [Ca(2+)](i) elevation mediated by influx of extracellular Ca(2+). This effect was abolished by low micromolar concentration of the TRPV4 inhibitor Ruthenium Red. Immunofluorescence and immunogold electron microscopy of rat brain revealed that TRPV4 was enriched in astrocytic processes of the superficial layers of the neocortex and in astrocyte end feet facing pia and blood vessels. Collectively, these data indicate that cultured cortical astroglia express functional TRPV4 channels. They also demonstrate that TRPV4 is particularly abundant in astrocytic membranes at the interface between brain and extracerebral liquid spaces. Consistent with its roles in other tissues, these results support the view that TRPV4 might participate in astroglial osmosensation and thus play a key role in brain volume homeostasis.


Assuntos
Astrócitos/fisiologia , Expressão Gênica/fisiologia , Lobo Occipital/citologia , Canais de Cátion TRPV/metabolismo , Animais , Animais Recém-Nascidos , Astrócitos/citologia , Cálcio/metabolismo , Membrana Celular/metabolismo , Células Cultivadas , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Estimulação Elétrica/métodos , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Microscopia Imunoeletrônica/métodos , Lobo Occipital/metabolismo , Lobo Occipital/ultraestrutura , Técnicas de Patch-Clamp , Forbóis/farmacologia , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Rutênio Vermelho/farmacologia , Canais de Cátion TRPV/genética , Transfecção/métodos
8.
Exp Gerontol ; 42(10): 944-50, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17606349

RESUMO

Many studies have demonstrated the association between telomere length in mitotic cells and carcinogenesis and mortality, but little attention has been focused on post-mitotic cells and human life expectancy. We assessed the relationship between telomere length in cerebral gray and white matter and longevity in 72 autopsied Japanese patients aged 0-100 years using Southern blot hybridization. The mean telomere lengths in the gray and white matter were 12.3+/-2.5 kilobase pairs and 11.4+/-2.1 kilobase pairs, respectively. The mean telomere lengths in 60-69 year decadal group were less than those of neonates, and declined further in the 70-79-year age group, but those in groups of further advanced age were longer than in the 70-79 year group (70-79<80-89<90-100 years of age). Thus, the 90-100-year age group possessed significantly longer telomeres than the 70s (p=0.029). Autopsy protocols showed a decrease in the rate of cancer death in individuals in their 80s (p=0.041) and 90s (p=0.017) versus those in their 60s, and in their 80s the mean telomere length in the gray matter from cancer death patients was significantly shorter than that of patients who died of other diseases (p=0.04). These data suggest that innate telomere lengths are maintained very well in the cerebrum, and are associated with longevity. Our study lends indispensable support to the hypothesis that longer telomeres protect the genome from instability (a major cause of carcinogenesis) and are beneficial for longevity.


Assuntos
Longevidade/genética , Lobo Occipital/ultraestrutura , Telômero/ultraestrutura , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Southern Blotting , Transformação Celular Neoplásica/genética , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade
9.
J Neurosci ; 25(1): 1-9, 2005 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-15634761

RESUMO

The influence of neuronal activity on cortical axon branching was studied by imaging axons of layer 2/3 neurons in organotypic slice cultures of rat visual cortex. Upper layer neurons labeled by electroporation of plasmid encoding yellow fluorescent protein were observed by confocal microscopy. Time-lapse observation of single-labeled axons showed that axons started to branch after 8-10 d in vitro. Over the succeeding 7-10 d, branch complexity gradually increased by both growth and retraction of branches, resulting in axon arbors that morphologically resembled those observed in 2- to 3-week-old animals. Electrophysiological recordings of neuronal activity in the upper layers, made using multielectrode dishes, showed that the frequency of spontaneous firing increased dramatically approximately 10 d in vitro and remained elevated at later stages. To examine the involvement of spontaneous firing and synaptic activity in branch formation, various blockers were applied to the culture medium. Cultures were silenced by TTX or by a combination of APV and DNQX but exhibited a homeostatic recovery of spontaneous activity over several days in the presence of blockers of either NMDA-type or non-NMDA-type glutamate receptors alone. Axonal branching was suppressed by TTX and AMPA receptor blockade but not by NMDA receptor blockade. We conclude that cortical axon branching is highly dynamic and that neural activity regulates the early developmental branching of upper layer cortical neurons through the activation of AMPA-type glutamate receptors.


Assuntos
Axônios/fisiologia , Axônios/ultraestrutura , Córtex Cerebral/fisiologia , Córtex Cerebral/ultraestrutura , Neurônios/fisiologia , Valina/análogos & derivados , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Axônios/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/crescimento & desenvolvimento , Eletroporação , Proteínas Luminescentes , Microeletrodos , Microscopia Confocal , Neocórtex/fisiologia , Neocórtex/ultraestrutura , Lobo Occipital/fisiologia , Lobo Occipital/ultraestrutura , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/fisiologia , Tetrodotoxina/farmacologia , Técnicas de Cultura de Tecidos , Valina/farmacologia
10.
Neuroscience ; 112(3): 665-76, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12074908

RESUMO

In adults and children, head trauma can have long-term neuropathological and functional consequences. The thalamus is a major site of remote neurodegeneration after cortical damage in adult humans and experimental animals, but less is known about thalamic responses to cortical injury in the immature brain. This study introduces an in vivo model of axotomy/target deprivation-induced neuronal apoptosis in the dorsal lateral geniculate nucleus of the thalamus produced by unilateral ablation of the occipital cortex in the immature mouse. We specifically examined whether occipital cortex ablation in the immature brain causes apoptotic death of projection neurons in the dorsal lateral geniculate nucleus. After unilateral occipital cortex aspiration, 10-day-old C57BL/6 mice were recovered for up to 28 days. Fluorogold-prelabeled thalamocortical projection neurons were apoptotic at 36-48 h after ablation. The structural progression of apoptosis in the immature lateral geniculate nucleus reveals typical chromatolytic morphology by 18-24 h, followed by cytoplasmic shrinkage and chromatin condensation characteristic of end-stage apoptosis after 36-48 h. Electron microscopy confirmed the presence of apoptosis. This study shows internucleosomal DNA fragmentation and expression of cleaved caspase-3 occurs rapidly, being noted first at 18 h, well before the peak of apoptotic cell death occurring at 36 h after cortical damage in the immature brain. From these data we suggest that axotomy/target deprivation-induced cell death in the immature brain may: (1) differ from that previously reported in adult mice with respect to the time required for progression to cell death; (2) be mediated by caspase-3 activation.


Assuntos
Animais Recém-Nascidos/fisiologia , Apoptose , Lesões Encefálicas/fisiopatologia , Neurônios/fisiologia , Lobo Occipital/lesões , Tálamo/fisiopatologia , Animais , Lesões Encefálicas/patologia , Caspase 3 , Caspases/química , Caspases/metabolismo , Fragmentação do DNA , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica , Degeneração Neural/fisiopatologia , Nucleossomos/fisiologia , Lobo Occipital/ultraestrutura , Transmissão Sináptica , Fatores de Tempo
11.
Biol Chem ; 382(6): 925-31, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11501757

RESUMO

Great attention has been devoted both to ageing phenomena at the mitochondrial level and to the antioxidant status of membrane structures. These kinds of investigations are difficult to perform in the brain because of its heterogeneity. It is known that synaptic heavy mitochondria (HM) may represent an aged mitochondrial population characterized by a partial impairment of their typical mitochondrial function. We arranged a novel system requiring no extraction procedure, very limited handling of the samples and their direct injection into the HPLC apparatus, to carry out, for the first time, a systematic and concomitant determination of vitamin E, Coenzyme Q9 (CoQ9) and Coenzyme Q10 (CoQ10) contents in rat brain mitochondria. The trends found for CoQ9 and CoQ10 levels in synaptic and non-synaptic occipital cerebral cortex mitochondria during rat ageing are consistent with previous data. Hydroperoxides (HP) differed with age and it was confirmed that in the HM fraction the summation of contributions results in an oxidatively jeopardized subpopulation. We found that vitamin E seems to increase with age, at least in non-synaptic free (FM) and synaptic light (LM) mitochondria, while it was inclined to remain substantially constant in HM.


Assuntos
Envelhecimento/metabolismo , Antioxidantes/análise , Peroxidação de Lipídeos/fisiologia , Mitocôndrias/metabolismo , Lobo Occipital/metabolismo , Ubiquinona/análogos & derivados , Fatores Etários , Animais , Cromatografia Líquida de Alta Pressão/instrumentação , Coenzimas , Desenho de Equipamento , Peróxidos Lipídicos/análise , Masculino , Lobo Occipital/ultraestrutura , Ratos , Ratos Sprague-Dawley , Ubiquinona/análise , Vitamina E/análise
12.
Synapse ; 39(3): 257-66, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11169774

RESUMO

We studied the influence of cocaine use on the structure of neurons in brain regions that contribute to its rewarding effects by allowing rats to self-administer cocaine (0.33 mg/infusion) for 1 h a day for 1 month. Control animals were left undisturbed or allowed to work for food for the same period of time. After an additional 1 month drug-free period the brains were processed for Golgi-Cox staining. In rats that self-administered cocaine, but not rats that worked for food, there was a significant increase in dendritic branching and in the density of dendritic spines on medium spiny neurons in the shell of the nucleus accumbens and on pyramidal cells in the prefrontal and parietal (but not occipital) cortex. There was also a 2.6-fold increase in the incidence of spines with multiple heads (branched spines) on medium spiny neurons. Finally, in the prefrontal cortex some of the apical dendrites of pyramidal cells appeared misshaped, having large bulbous structures on their terminal tips. We speculate that cocaine self-administration experience alters patterns of synaptic connectivity within limbocortical circuitry that is thought to contribute to cocaine's incentive motivational effects and may have neuropathological effects in frontal areas involved in decision making and judgment. Together, these two classes of drug-induced neuroadaptations may contribute to the development of addiction.


Assuntos
Cocaína/farmacologia , Dendritos/ultraestrutura , Inibidores da Captação de Dopamina/farmacologia , Neocórtex/ultraestrutura , Núcleo Accumbens/ultraestrutura , Córtex Pré-Frontal/ultraestrutura , Animais , Dendritos/efeitos dos fármacos , Masculino , Neocórtex/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Lobo Occipital/efeitos dos fármacos , Lobo Occipital/ultraestrutura , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/ultraestrutura , Córtex Pré-Frontal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
13.
Folia Neuropathol ; 38(3): 111-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11043972

RESUMO

In adults, under physiological conditions proteins of the major histocompatibility complex, class II (MHC II) molecules are synthesized and then presented on the surface of the cells known under a common name as antigen presenting cells (APCs). Dendritic cells (DCs), microglia, macrophages, ameboid microglia and lymphocytes B are qualified as APCs. The aim of present study was to evaluate the expression of MHC II molecules in the central nervous system (CNS) and hematopoietic organs during the fetal development. Observations were made on the cerebral occipital lobe, cerebellum, thymus, spleen and liver of 30 normal human fetuses, between 11 and 22 week of gestation (GW). Histological, histochemical and immunohistochemical techniques were used to identify cells with expression of MHC II molecules. In the brain, MHC II molecules were detected on macrophages/ameboid microglia in meninges, choroid plexus and single cells of ramified microglia in deeper layers of the cortex and white matter. In the other organs besides macrophages and dendritic cells, MHC II molecules were also immunopositive in thymic epithelial cells, and in the spleen and liver also in other cells of stroma and lobule. The expression of MHC II molecules on so extensive population of cells, at an early stage of the fetal development, may evidence their significant involvement in histogenesis and morphogenesis. It seems that in adults the complex of MHC II with protein is originated from the foreign antigen. On the contrary, during normal fetal development the complex of MHC II with protein origins most probably from the fetus own structures.


Assuntos
Cerebelo/crescimento & desenvolvimento , Desenvolvimento Embrionário e Fetal/genética , Genes MHC da Classe II/genética , Sistema Hematopoético/ultraestrutura , Lobo Occipital/crescimento & desenvolvimento , Adulto , Cerebelo/ultraestrutura , Humanos , Microglia/ultraestrutura , Lobo Occipital/ultraestrutura
14.
J Med Chem ; 43(10): 2064-71, 2000 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-10821718

RESUMO

A novel class of tricyclic tropane analogues has been synthesized by making use of radical cyclization technology in combination with the Stille coupling reaction. As hybrids between tropanes and quinuclidines, these tropaquinuclidines represent a significant structural departure from many of the other classes of tropane ligands synthesized to date. This structure class is characterized by the boat conformation of the tropane ring and the orientation of the additional bridge (and therefore of the nitrogen lone pair) together with the unusual placement of the aromatic moiety. All compounds were tested for their ability to inhibit monoamine reuptake under identical conditions. The ability to inhibit reuptake of dopamine in comparison to cocaine is generally decreased in this series but for one compound. (1S,3R, 6S)-(Z)-9-(thienylmethylene)-7-azatricyclo[4.3.1.0(3, 7)]decane-2beta-carboxylic acid methyl ester (5h) exhibits reasonable activity at the dopamine transporter (DAT) (K(i) = 268 nM) and good activity at the norepinephrine transporter (NET) (K(i) = 26 nM). The potency and selectivity shown by some of these ligands for the NET, serotonine transporter (SERT), or NET/SERT is striking, particularly in view of the displacement of the aromatic ring in this series from its usual position at C-3 in the WIN analogues. Thus, (1S,3R,6S)-(Z)-9-(4-biphenylylmethylene)-7-azatricyclo[4.3.1 . 0(3,7)]decane-2beta-carboxylic acid methyl ester (5a) is a selective inhibitor of norepinephrine reuptake (K(i) = 12 nM). Its p-methoxy analogue 5c is a mixed inhibitor of norepinephrine and serotonin reuptake (K(i) = 187 nM at the NET and 56 nM at the SERT). The most active and selective compound we found in the present series is compound 8b [(1S,3R,6S)-2-(acetoxymethyl)-(Z)-9-(3, 4-dichlorophenylmethylene)-7-azatricyclo[4.3.1.0(3,7)]decane ]. This compound is a potent (K(i) = 1.6 nM) and selective inhibitor of serotonin reuptake into rat midbrain synaptosomes. Its selectivity is about 400-fold over the NET and about 1000-fold over the DAT. The results of this study further demonstrate the possibility of tuning the selectivity of tropane analogues toward the SERT or NET binding site. The ligands disclosed herein provide additional pharmacological tools of use in attempting to correlate structure and transporter selectivity with in vivo studies of behavioral outcomes.


Assuntos
Proteínas de Transporte/antagonistas & inibidores , Compostos Heterocíclicos com 3 Anéis/síntese química , Compostos Heterocíclicos com 3 Anéis/farmacologia , Glicoproteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Simportadores , Tropanos/química , Animais , Proteínas de Transporte/metabolismo , Corpo Estriado/ultraestrutura , Ciclização , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina , Glicoproteínas de Membrana/metabolismo , Mesencéfalo/ultraestrutura , Conformação Molecular , Norepinefrina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , Lobo Occipital/ultraestrutura , Lobo Parietal/ultraestrutura , Ratos , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina , Relação Estrutura-Atividade , Sinaptossomos/metabolismo , Trítio
15.
J Neurosci ; 17(21): 8491-7, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9334421

RESUMO

Experience-dependent changes in behavior are thought to involve structural modifications in the nervous system, especially alterations in patterns of synaptic connectivity. Repeated experience with drugs of abuse can result in very long-lasting changes in behavior, including a persistent hypersensitivity (sensitization) to their psychomotor activating and rewarding effects. It was hypothesized, therefore, that repeated treatment with the psychomotor stimulant drug amphetamine, which produces robust sensitization, would produce structural adaptations in brain regions that mediate its psychomotor activating and rewarding effects. Consistent with this hypothesis, it was found that amphetamine treatment altered the morphology of neurons in the nucleus accumbens and prefrontal cortex. Exposure to amphetamine produced a long-lasting (>1 month) increase in the length of dendrites, in the density of dendritic spines, and in the number of branched spines on the major output cells of the nucleus accumbens, the medium spiny neurons, as indicated by analysis of Golgi-stained material. Amphetamine treatment produced similar effects on the apical (but not basilar) dendrites of layer III pyramidal neurons in the prefrontal cortex. The ability of amphetamine to alter patterns of synaptic connectivity in these structures may contribute to some of the long-term behavioral consequences of repeated amphetamine use, including amphetamine psychosis and addiction.


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas/patologia , Estimulantes do Sistema Nervoso Central/farmacologia , Dextroanfetamina/farmacologia , Neurônios/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Animais , Dano Encefálico Crônico/induzido quimicamente , Dano Encefálico Crônico/patologia , Estimulantes do Sistema Nervoso Central/toxicidade , Dendritos/efeitos dos fármacos , Dendritos/ultraestrutura , Dextroanfetamina/toxicidade , Masculino , Neurônios/ultraestrutura , Núcleo Accumbens/ultraestrutura , Lobo Occipital/efeitos dos fármacos , Lobo Occipital/ultraestrutura , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/ultraestrutura , Córtex Pré-Frontal/ultraestrutura , Psicoses Induzidas por Substâncias/patologia , Transtornos Psicóticos , Células Piramidais/efeitos dos fármacos , Células Piramidais/ultraestrutura , Ratos , Ratos Sprague-Dawley , Sinapses/ultraestrutura
16.
Proc Natl Acad Sci U S A ; 94(10): 5401-4, 1997 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-9144249

RESUMO

Fragile X syndrome arises from blocked expression of the fragile X mental retardation protein (FMRP). Golgi-impregnated mature cerebral cortex from fragile X patients exhibits long, thin, tortuous postsynaptic spines resembling spines observed during normal early neocortical development. Here we describe dendritic spines in Golgi-impregnated cerebral cortex of transgenic fragile X gene (Fmr1) knockout mice that lack expression of the protein. Dendritic spines on apical dendrites of layer V pyramidal cells in occipital cortex of fragile X knockout mice were longer than those in wild-type mice and were often thin and tortuous, paralleling the human syndrome and suggesting that FMRP expression is required for normal spine morphological development. Moreover, spine density along the apical dendrite was greater in the knockout mice, which may reflect impaired developmental organizational processes of synapse stabilization and elimination or pruning.


Assuntos
Córtex Cerebral/ultraestrutura , Dendritos/patologia , Síndrome do Cromossomo X Frágil/patologia , Animais , Córtex Cerebral/patologia , Feminino , Síndrome do Cromossomo X Frágil/genética , Complexo de Golgi/patologia , Complexo de Golgi/ultraestrutura , Humanos , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Lobo Occipital/patologia , Lobo Occipital/ultraestrutura , Células Piramidais/patologia , Células Piramidais/ultraestrutura
17.
Acta Neuropathol ; 93(3): 310-6, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9083565

RESUMO

We report a case of ependymoma with unusual vacuolar features arising in the left occipital lobe of a 2-year-old child. The tumor was composed of cells with single or multiple cytoplasmic vacuoles and clear cells. Some cells showed a signet ring-like configuration. Clear cells were compactly arranged and showed an oligodendro-glioma-like appearance. In addition, there were cellular ependymoma-like areas including perivascular pseudorosettes. On immunohistochemistry, glial fibrillary acidic protein and vimentin were mainly detected in cytoplasmic processes, and epithelial membrane antigen (EMA) staining showed granular and small vesicular reactivity. Ultrastructural investigation demonstrated intercellular microrosettes with or without cilia and long zonula adherens-type junctions that are typical of ependymoma. Furthermore, many intracytoplasmic lumina (ICL) were observed. Some ICL had microvilli and some did not. The latter varied in size, and may have fused with each other to develop giant ICL which could correspond to the signet ring-like configuration. Small ICL without microvilli had an appearance similar to that of distended endoplasmic reticula. Serial semithin and ultrathin sections revealed that EMA-positive structures were consistent with ICL containing microvilli and intercellular microrosettes. To determine the presence of unusual vacuolated ependymoma, electron microscopical examination was required. However, light microscopy was useful for detecting EMA-positive microvesicular and granular structures.


Assuntos
Ependimoma/patologia , Lobo Occipital/patologia , Pré-Escolar , Ependimoma/ultraestrutura , Feminino , Humanos , Imuno-Histoquímica , Lobo Occipital/ultraestrutura
18.
Mol Aspects Med ; 18 Suppl: S279-82, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9266537

RESUMO

The coenzyme Q8 (CoQ8) and alpha-tocopherol contents of different mitochondrial fractions were investigated from occipital cerebral cortices of different ages. The highest CoQ8 and vitamin E concentrations were found in non-synaptic free mitochondria (FM) fractions. In several cases heavy mitochondria (HM) fractions displayed the lowest values. Occipital cerebral cortex mitochondria contained higher CoQ9 and lower CoQ10 amounts than those typical for other brain regions.


Assuntos
Envelhecimento/metabolismo , Mitocôndrias/química , Lobo Occipital/química , Sinapses/química , Ubiquinona/análogos & derivados , Ubiquinona/análise , Vitamina E/análise , Animais , Coenzimas , Masculino , Lobo Occipital/ultraestrutura , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley
19.
J Neurol Neurosurg Psychiatry ; 58(1): 65-9, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7823070

RESUMO

A case of familial Creutzfeldt-Jakob disease associated with a 144 base pair insertion in the open reading frame of the prion protein gene is described. Sequencing of the mutated allele showed an arrangement of six octapeptide repeats, distinct from that of a recently described British family with an insertion of similar size. Thirteen years previously the brother of the proband had died from "Huntington's disease", but re-examination of his neuropathology revealed spongiform encephalopathy and anti-prion protein immunocytochemistry gave a positive result. The independent evolution of at least two distinct pathological 144 base pair insertions in Britain is proposed. The importance of maintaining a high index of suspicion of inherited Creutzfeldt-Jakob disease in cases of familial neurodegenerative disease is stressed.


Assuntos
Síndrome de Creutzfeldt-Jakob/genética , Elementos de DNA Transponíveis , Príons/genética , Proteínas/genética , Sequência de Bases , Síndrome de Creutzfeldt-Jakob/diagnóstico , Síndrome de Creutzfeldt-Jakob/fisiopatologia , Primers do DNA , Diagnóstico Diferencial , Genoma Humano , Humanos , Doença de Huntington/diagnóstico , Doença de Huntington/fisiopatologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutagênese , Lobo Occipital/fisiopatologia , Lobo Occipital/ultraestrutura , Linhagem , Reação em Cadeia da Polimerase , Doenças Priônicas/fisiopatologia , Putamen/fisiopatologia , Putamen/ultraestrutura
20.
J Neurol Neurosurg Psychiatry ; 57(11): 1325-33, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7964806

RESUMO

Eight patients with Rasmussen's syndrome and epilepsia partialis continua were treated with high doses of steroids, including pulses of methylprednisolone and prednisone in decreasing doses. Three patients exhibited clinical, radiological, or histological evidence of bilateral involvement. Epilepsy and focal deficit decreased within six months in seven patients. Only five patients, in whom steroid treatment had begun less than 15 months after the onset of epilepsia partialis continua, experienced a lasting effect although they had periodic episodes of transient relapse. Treatment with high doses of steroids seems advisable during the first year after onset of epilepsia partialis continua, before hemiplegia has developed and in cases with bilateral involvement.


Assuntos
Epilepsias Parciais/tratamento farmacológico , Metilprednisolona/uso terapêutico , Adolescente , Idade de Início , Biópsia , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Doenças Desmielinizantes , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/fisiopatologia , Feminino , Lobo Frontal/fisiopatologia , Hemiplegia , Humanos , Imageamento por Ressonância Magnética , Masculino , Metilprednisolona/administração & dosagem , Metilprednisolona/efeitos adversos , Lobo Occipital/fisiopatologia , Lobo Occipital/ultraestrutura
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