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1.
Glia ; 72(6): 1165-1182, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38497409

RESUMO

Oligodendrocytes (OLs) are key players in the central nervous system, critical for the formation and maintenance of the myelin sheaths insulating axons, ensuring efficient neuronal communication. In the last decade, the use of human induced pluripotent stem cells (iPSCs) has become essential for recapitulating and understanding the differentiation and role of OLs in vitro. Current methods include overexpression of transcription factors for rapid OL generation, neglecting the complexity of OL lineage development. Alternatively, growth factor-based protocols offer physiological relevance but struggle with efficiency and cell heterogeneity. To address these issues, we created a novel SOX10-P2A-mOrange iPSC reporter line to track and purify oligodendrocyte precursor cells. Using this reporter cell line, we analyzed an existing differentiation protocol and shed light on the origin of glial cell heterogeneity. Additionally, we have modified the differentiation protocol, toward enhancing reproducibility, efficiency, and terminal maturity. Our approach not only advances OL biology but also holds promise to accelerate research and translational work with iPSC-derived OLs.


Assuntos
Células-Tronco Pluripotentes Induzidas , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Linhagem da Célula , Reprodutibilidade dos Testes , Neurogênese , Oligodendroglia/metabolismo , Diferenciação Celular/fisiologia , Fatores de Transcrição SOXE/genética , Fatores de Transcrição SOXE/metabolismo
2.
Ann Ig ; 35(6): 715-718, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37313798

RESUMO

Abstract: Our letter discusses the concept of 'Nutritional Prevention Hesitancy', comparing it to the well-studied phenomenon of 'Vaccine Hesitancy'. Both hesitancies can be fueled by 'infodemics', the rapid spread of accurate and inaccurate information that can lead to public confusion and mistrust in authoritative sources. Drawing parallels between the two, the text highlights that nutritional prevention hesitancy can result in individuals not adopting evidence-based nutritional strategies, potentially leading to poorer health outcomes. The text emphasizes the critical role of diet in preventing diseases such as heart disease, diabetes, and certain types of cancer, and underscores the need for multifaceted strategies to combat misinformation and promote healthier dietary habits.

3.
Ann Ig ; 35(5): 611-613, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37082929

RESUMO

Abstract: Italy's National Prevention Plan 2020-25 is the first to address nutritional prevention, highlighting its importance in combating chronic diseases. This letter discusses the relationship between food safety, nutritional security, and the need for nutritional prevention in the plan. Chronic diseases, such as cardiovascular disease, cancer, and diabetes, are significant public health concerns in Italy, with poor nutrition being a critical risk factor. Incorporating nutritional prevention can promote healthy eating habits, food security and sustainability, reduce healthcare costs, and promote social cohesion and equality. Successful implementation will require cooperation among the government, the private sector, and the civil society to ensure healthier food choices and prevent chronic diseases in Italy.


Assuntos
Custos de Cuidados de Saúde , Saúde Pública , Humanos , Itália
5.
Mol Neurodegener ; 19(1): 31, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38576039

RESUMO

BACKGROUND: Induced pluripotent stem cell-derived microglia (iMGL) represent an excellent tool in studying microglial function in health and disease. Yet, since differentiation and survival of iMGL are highly reliant on colony-stimulating factor 1 receptor (CSF1R) signaling, it is difficult to use iMGL to study microglial dysfunction associated with pathogenic defects in CSF1R. METHODS: Serial modifications to an existing iMGL protocol were made, including but not limited to changes in growth factor combination to drive microglial differentiation, until successful derivation of microglia-like cells from an adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) patient carrying a c.2350G > A (p.V784M) CSF1R variant. Using healthy control lines, the quality of the new iMGL protocol was validated through cell yield assessment, measurement of microglia marker expression, transcriptomic comparison to primary microglia, and evaluation of inflammatory and phagocytic activities. Similarly, molecular and functional characterization of the ALSP patient-derived iMGL was carried out in comparison to healthy control iMGL. RESULTS: The newly devised protocol allowed the generation of iMGL with enhanced transcriptomic similarity to cultured primary human microglia and with higher scavenging and inflammatory competence at ~ threefold greater yield compared to the original protocol. Using this protocol, decreased CSF1R autophosphorylation and cell surface expression was observed in iMGL derived from the ALSP patient compared to those derived from healthy controls. Additionally, ALSP patient-derived iMGL presented a migratory defect accompanying a temporal reduction in purinergic receptor P2Y12 (P2RY12) expression, a heightened capacity to internalize myelin, as well as heightened inflammatory response to Pam3CSK4. Poor P2RY12 expression was confirmed to be a consequence of CSF1R haploinsufficiency, as this feature was also observed following CSF1R knockdown or inhibition in mature control iMGL, and in CSF1RWT/KO and CSF1RWT/E633K iMGL compared to their respective isogenic controls. CONCLUSIONS: We optimized a pre-existing iMGL protocol, generating a powerful tool to study microglial involvement in human neurological diseases. Using the optimized protocol, we have generated for the first time iMGL from an ALSP patient carrying a pathogenic CSF1R variant, with preliminary characterization pointing toward functional alterations in migratory, phagocytic and inflammatory activities.


Assuntos
Leucoencefalopatias , Microglia , Adulto , Humanos , Diferenciação Celular , Leucoencefalopatias/metabolismo , Leucoencefalopatias/patologia , Microglia/metabolismo , Fosforilação , Células-Tronco/metabolismo
6.
Ultrasound Obstet Gynecol ; 36(1): 26-31, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20131338

RESUMO

OBJECTIVES: To examine, in patients with premature rupture of the amniotic membranes (PROM) at < 34 weeks of gestation, the relationship between fetal myocardial performance measured by the Tei index and fetal inflammatory response syndrome (FIRS). METHODS: A case-control study was conducted including 15 preterm PROM patients with gestational age between 24 and 33 weeks admitted to Hospital de Clínicas de Porto Alegre, and 15 controls with the same gestational age range. Fetal echocardiography with Doppler was performed at admission for the preterm PROM group, with serial examinations every 7-10 days thereafter until delivery, and at the time of inclusion in the control group. Flow velocity waveforms were obtained for the left ventricle, from which the Tei index was calculated. Placental histopathology and perinatal outcome were compared between the groups. RESULTS: The left ventricular Tei index was significantly greater in fetuses with preterm PROM compared with controls (0.63 +/- 0.13 vs. 0.51 +/- 0.10, P = 0.007). While there was no difference in isovolumetric times, the left ventricular ejection time was significantly shorter in the preterm PROM group (164 +/- 17 ms vs. 184 +/- 16 ms, P = 0.003). In the preterm PROM group, neonatal sepsis was diagnosed in 73.3%, and funisitis and chorionic vasculitis confirmed FIRS in 53.3%, compared with 6.7% for these three diagnoses in controls (P = 0.001). CONCLUSIONS: These data provide further evidence that cardiac dysfunction is present in the setting of preterm PROM. The study of myocardial performance with the Tei index is a novel non-invasive approach to assess cardiac function and monitor the fetus affected with FIRS.


Assuntos
Corioamnionite/diagnóstico , Coração Fetal/diagnóstico por imagem , Ruptura Prematura de Membranas Fetais/diagnóstico por imagem , Adulto , Cardiotocografia , Estudos de Casos e Controles , Corioamnionite/fisiopatologia , Ecocardiografia , Feminino , Coração Fetal/fisiopatologia , Ruptura Prematura de Membranas Fetais/fisiopatologia , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez , Nascimento Prematuro , Volume Sistólico/fisiologia , Ultrassonografia Pré-Natal/métodos
7.
Sci Rep ; 7(1): 16403, 2017 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-29180662

RESUMO

Aftershocks number decay through time, depending on several parameters peculiar to each seismogenic regions, including mainshock magnitude, crustal rheology, and stress changes along the fault. However, the exact role of these parameters in controlling the duration of the aftershock sequence is still unknown. Here, using two methodologies, we show that the tectonic setting primarily controls the duration of aftershocks. On average and for a given mainshock magnitude (1) aftershock sequences are longer and (2) the number of earthquakes is greater in extensional tectonic settings than in contractional ones. We interpret this difference as related to the different type of energy dissipated during earthquakes. In detail, (1) a joint effect of gravitational forces and pure elastic stress release governs extensional earthquakes, whereas (2) pure elastic stress release controls contractional earthquakes. Accordingly, normal faults operate in favour of gravity, preserving inertia for a longer period and seismicity lasts until gravitational equilibrium is reached. Vice versa, thrusts act against gravity, exhaust their inertia faster and the elastic energy dissipation is buffered by the gravitational force. Hence, for seismic sequences of comparable magnitude and rheological parameters, aftershocks last longer in extensional settings because gravity favours the collapse of the hangingwall volumes.

8.
Ann Ig ; 17(3): 243-52, 2005.
Artigo em Italiano | MEDLINE | ID: mdl-16041926

RESUMO

Food service establishments are recognized as a critical sector concerning foodborne diseases occurrence, that is associated to contributing factors such as the anticipated preparation of meals that are often highly handled, and long-time distributed. A survey has been planned to evaluate the application of HACCP plan, in order to select a statistically representative sample of food services (restaurant, pizza-shop, bar, ..) in two Milan area' Public Health Units (PHU). During the inspections a proper check-list has been filled up in order to give a conformity evaluation about the global situation and about three specific sections: hygiene of food-handlers, procedures control, temperatures management. The food services have been found satisfactory in 9/106 and 5/54 cases in Milan City and in hinterland, respectively; among the two areas, highly significant differences have been revealed about temperatures management (68% and 28% unsatisfactory, respectively). In Milan City restaurants provided with HACCP plan scores are significantly different from unprovided restaurants scores (global and the three sections' evaluation); in Milan hinterland differences between provided and unprovided HACCP plan restaurants regard temperature management scores only. Useful suggestions to improve the quality of surveillance activity come from complex and heterogeneous findings shown in this study.


Assuntos
Monitoramento Ambiental/métodos , Serviços de Alimentação/organização & administração , Setor Público , Restaurantes , Conformidade Social , Estudos de Casos e Controles , Área Programática de Saúde , Serviços de Alimentação/legislação & jurisprudência , Humanos , Itália
9.
Neuroscience ; 79(1): 1-5, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9178862

RESUMO

Excitotoxicity has been proposed to contribute to neuronal loss in a broad spectrum of neurodegenerative conditions such as ischemia, hypoglycaemic coma or cerebral trauma. Excitotoxic neuronal injury appears to be mediated mainly by the over-activation of glutamate receptors, especially N-methyl-D-aspartate receptors, with subsequent excessive Ca2+ influx. Concurrent with the activation of glutamate-gated ion channels, metabotropic glutamate receptors (mGluR), which are G-protein coupled receptors, are also expected to be activated. Excessive stimulation of phospholipase C-coupled mGluR, mGluR1 and mGluRS, has been suggested to have neurotoxic consequences. However, the contribution of mGluR activation on excitotoxicity is still unclear and controversial. Here we report that, following ischemic and excitotoxic brain injuries, inactivation of mGluR1 does not prevent excitotoxic neuronal damage. Given the evidence that agonists at this group of mGluR promoted neuronal death in cerebrocortical cultures after oxygen-glucose deprivation or after N-methyl-D-aspartate exposure, our findings suggest that mGluR-mediated excitotoxicity is unlikely associated with mGluR1 but rather with other PLC-coupled mGluR.


Assuntos
Benzoatos/toxicidade , Encéfalo/fisiopatologia , Infarto Cerebral/fisiopatologia , Antagonistas de Aminoácidos Excitatórios/toxicidade , Glicina/análogos & derivados , Ataque Isquêmico Transitório/fisiopatologia , Neurônios/fisiologia , Receptores de Glutamato Metabotrópico/fisiologia , Análise de Variância , Animais , Benzoatos/administração & dosagem , Biomarcadores , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Infarto Cerebral/patologia , Ventrículos Cerebrais/efeitos dos fármacos , Ventrículos Cerebrais/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Proteína Glial Fibrilar Ácida/análise , Glicina/administração & dosagem , Glicina/toxicidade , Injeções Intraventriculares , Ataque Isquêmico Transitório/patologia , Ácido Caínico/administração & dosagem , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurotoxinas , Receptores de Glutamato Metabotrópico/deficiência , Receptores de Glutamato Metabotrópico/genética , Fosfolipases Tipo C/metabolismo
10.
Psychopharmacology (Berl) ; 121(2): 282-3, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8545535

RESUMO

Few reports have described conditions under which nicotine self-administration occurs in rats. In this study, rats which initially lever pressed for cocaine infusion (0.05 mg/kg) during 1 h experimental sessions continued to obtain similar infusion numbers when nicotine (0.03 mg/kg) was available. When saline was substituted for nicotine, infusions decreased from 11.8 +/- 4.5/h to 5.4 +/- 1.1/h but returned to pre-saline levels when it was reintroduced (12.0 +/- 5.4/h). These results indicate that nicotine can serve as a positive reinforcer for rats under the historical and schedule conditions described.


Assuntos
Cocaína/farmacologia , Nicotina/farmacologia , Reforço Psicológico , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Autoadministração , Cloreto de Sódio/farmacologia
11.
Psychopharmacology (Berl) ; 127(2): 102-7, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8888374

RESUMO

The effect of non-contingent priming injections of nicotine on the reinstatement of drug-seeking behaviour was studied in rats following the long-term extinction of nicotine self-administration. Male rats were trained to lever press for 0.03 mg/kg per infusion of intravenous nicotine. Nicotine maintained a robust self-administration behaviour (11.5 +/- 1.2; mean+/-SEM infusions/1-h session). When nicotine availability was discontinued, and only a non-contingent saline infusion was presented to the experimental subjects at the beginning of each daily session, responding for the drug-paired lever decreased to low values. After 4-13 sessions, responding extinguished. During this "extinction" period, non-contingent priming infusions of nicotine 0.001, 0.003, 0.01 or 0.03 mg/kg per infusion induced reinstatement of responding for the drug-paired lever. The increased responding, compared with the corresponding previous day on saline, was observed at all four nicotine doses but was not statistically significant for the higher priming dose (0.03 mg/kg per infusion). These preliminary results indicate that nicotine priming is able to induce reinstatement of drug-seeking behaviour in rats similarly to other reinforcing drugs. The present findings show analogies with similar phenomena described in ex-smokers and support the addictive role of nicotine in tobacco smoking.


Assuntos
Extinção Psicológica/efeitos dos fármacos , Nicotina/farmacologia , Animais , Masculino , Ratos , Ratos Wistar , Reforço Psicológico , Autoadministração , Fumar , Transtornos Relacionados ao Uso de Substâncias
12.
Eur J Pharmacol ; 216(2): 335-6, 1992 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-1397020

RESUMO

The role of the glutamate 'metabotropic' receptor was investigated in an experimental model of focal ischaemia-induced neurodegeneration. The metabotropic agonist, trans-1-amino cyclopentane-1,3-dicarboxylic acid (t-ACPD, 20 mg/kg i.p.), was administered to mice immediately after middle cerebral artery occlusion (MCAO), which causes cerebral infarct. Seven days after MCAO, the mean infarct volume value of the t-ACPD-treated group (mean +/- S.E. = 4.57 +/- 0.73 mm3) was significantly reduced, by 34.3%, compared to the vehicle-treated group (mean +/- S.E. = 6.95 +/- 0.59 mm3, P less than 0.01). This suggests that metabotropic receptor activation in the adult brain reduces excitotoxicity.


Assuntos
Cicloleucina/análogos & derivados , Ataque Isquêmico Transitório/tratamento farmacológico , Receptores de Glutamato/metabolismo , Animais , Artérias Cerebrais , Cicloleucina/farmacologia , Cicloleucina/uso terapêutico , Modelos Animais de Doenças , Ataque Isquêmico Transitório/metabolismo , Masculino , Camundongos , Receptores de Glutamato/efeitos dos fármacos
13.
Behav Pharmacol ; 6(1): 32-39, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11224309

RESUMO

Reexposure to alcohol may induce subjective craving and relapse to drug self-administration in ex-alcoholics. In this study, we proposed a rat model of "first-drink"-induced drug-seeking relapse. Responding was established in Long Evans rats under a fixed-ratio [FR5:S(1)] schedule for oral ethanol. Substitution of water for ethanol solution resulted in extinction of the self-administration. When responding for 8% ethanol and ethanol intake were stable for at least three consecutive 30min sessions, ethanol delivery was discontinued and only three water dipper cup presentations were available upon responding (3[FR5:water]). When the number of active lever presses decreased to a low stable level, responding was considered extinguished. In Experiment 1, subjects under "extinction" were challenged with three 8% ethanol dipper cup presentations. The re-exposure to ethanol was able to significantly reinstate responding in all subjects. Latency to complete the ethanol presentation significantly decreased compared to the value observed during the previous "extinction" session. In Experiment 2, other subjects were tested for extinction and then reexposed to 4, 8 or 16% ethanol. All three concentrations significantly increased active lever presses, but with different patterns of responding. The resumption of responding was linearly correlated to the ethanol concentration but no significant dose-effect relationship was found. In Experiment 3, reexposure to 8% ethanol in nondeprived rats induced a resumption of responding not significantly different from the effect observed in a restricted diet condition. These results demonstrate that ethanol reexposure is able to reinstate ethanol-seeking behaviour in rats with a past history of ethanol self-administration, and that this effect does not depend on a food motivation drive related to the calorific value of ethanol.

14.
Lab Anim ; 47(3): 194-202, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23760962

RESUMO

Despite the fact that sheep are a widely used animal model in cardiovascular research, reference values for transthoracic echocardiography in normal growing animals are not available. Eight healthy female lambs underwent two-dimensional, M-mode and pulsed wave Doppler echocardiographic examination at 100 days of age and every three months thereafter over a 12-month period. The study was conducted under sedation with midazolam, butorphanol and constant rate infusion of intravenous propofol. Their growth phase was completed at about one year of age. All the echocardiographic parameters considered were significantly correlated with body weight and age class except for the left ventricular systolic and diastolic diameters. Functional indices were not correlated to body weight or age except for the E-point to septal separation distance (EPSS). Doppler-derived parameters were not influenced by independent variables. Transthoracic echocardiography can be considered an applicable method for cardiovascular research using a growing lamb animal model after appropriate adjustments for age and body size.


Assuntos
Ecocardiografia/veterinária , Coração/anatomia & histologia , Ovinos/anatomia & histologia , Animais , Butorfanol/administração & dosagem , Ecocardiografia Doppler de Pulso/veterinária , Feminino , Hipnóticos e Sedativos/administração & dosagem , Infusões Intravenosas/veterinária , Midazolam/administração & dosagem , Propofol/administração & dosagem , Valores de Referência , Ovinos/crescimento & desenvolvimento , Fatores de Tempo
15.
JIMD Rep ; 2: 91-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23430859

RESUMO

BH4 therapy is an advancement in the treatment of phenylketonuria, reducing blood phenylalanine (phe) levels and increasing tolerance to natural proteins of responding patients. We report the results of 16 patients undergoing long-term BH4 treatment. Responding patients to BH4 was usually based on 24-h loading tests; a ≥30% decrease in blood phe was considered a positive response. Weekly loading made it possible to identify an additional "slow responder." The 16 responders constitute 24.6% of patients who completed the trial (87.5% of responders in mild hyperphenylalaninemia, 38.1% in mild PKU, and 2.8% in classical PKU).Mean dose of BH4 used was 9.75 ± 0.9 mg/kg per day, during a mean of 62 months. Age at treatment start was below 4 years in seven patients; five of which begun treatment during their first month since birth. All but one patient showed good treatment compliance; six continue on BH4 monotherapy without dietary phe restriction; six showed an increase in phe tolerance of 24-55%; and in the five patients who received treatment since the neonatal period an increase in phe tolerance following the phase of maximum growth has persisted. None of the patients showed side effects except one whom vomiting at the beginning of the treatment.Testing at the time of diagnosis in the neonatal period is very appropriate, and if there is a positive response, the patient can be treated with BH4 from onset with the advantage of being able to continue breast-feeding.

16.
Neuropharmacology ; 60(2-3): 328-35, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20868698

RESUMO

Selective NPY-Y5 antagonists are known to reduce NPY-evoked increase of food intake under free feeding conditions and drug-reinforced operant responding in rodents suggesting that NPY-Y5 receptors can regulate reinforcers, potentially by modulating the hypothalamic-limbic reward system. However, evidence published to date has revealed a limited expression of NPY-Y5 in the limbic areas. Thus, the first aim of the present study was to investigate the distribution of NPY-Y5 receptor binding sites in rat mesocorticolimbic projection areas such as the nucleus accumbens (NAc), medial prefrontal cortex (mPFC), and lateral hypothalamus (LH). Since mesocorticolimbic release of monoamines has been typically associated to the rewarding and motivational significance of reinforcers, we then compared the ability of NPY and an NPY-Y5 selective agonist, [cPP1-7,NPY19-23,Ala31,Aib32,Gln34]hPP, to evoke changes in extracellular monoamines from these brain regions using in vivo microdialysis techniques. Intracerebral doses of each compound were selected on the basis of those previously demonstrated to trigger food intake in a separate set of animals. We found that NPY-Y5 receptors were widely distributed in both the NAc and mPFC but not in the LH nuclei. Central administration of either NPY (4.5 nmol/rat) or the NPY-Y5 agonist (0.6 nmol/rat) induced a significant increase of dopamine (DA) output of up to 150% of basal values in the NAc. In addition, NPY induced a stepped increase of norepinephrine (NE) outflow in the NAc area. Also extracellular levels of NE levels were increased by both treatments in the mPFC (150% vs basal concentration). Hypothalamic monoamine levels were unaffected by both treatments. Extracellular serotonin (5-HT) levels were also unchanged in all regions. Given the NPY-Y5 agonist paralleled the in vivo ability of NPY to increase DA, these data suggest that the release of NPY may modulate behaviours associated to accumbal DA release such reward and reinforcement by, at least in part, acting on mesocorticolimbic NPY-Y5 receptors.


Assuntos
Monoaminas Biogênicas/metabolismo , Sistema Límbico/metabolismo , Neuropeptídeo Y/administração & dosagem , Neuropeptídeos/administração & dosagem , Córtex Pré-Frontal/metabolismo , Receptores de Neuropeptídeo Y/agonistas , Animais , Dopamina/metabolismo , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Sistema Límbico/efeitos dos fármacos , Masculino , Norepinefrina/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Neuropeptídeo Y/metabolismo , Serotonina/metabolismo
18.
Pharmacol Toxicol ; 70(2): 115-20, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1380708

RESUMO

A behavioural study of the domoic acid (DOM)-induced convulsive behaviour after intracerebroventricular administration was carried out in rats and mice. DOM-induced behaviours were compared to those elicited by other excitatory amino acid (EAA) agonists N-methyl-D-aspartate (NMDA), alpha-amino-3- hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid (KA), in such a way as to assess the possible similarities between DOM-induced effects and EAA subtype receptor activation in vivo. In rat, DOM (0.03-3 nmol/rat) caused a complex pattern of convulsive behaviour, quantified by means of a 15-point rating scale. DOM-induced behavioural profile was characterized at the lower doses by "preconvulsive" behaviours as wet dog shakes, hypermotility, mild facial clonus. At higher doses, DOM caused clonic convulsions followed by the "status epilepticus" syndrome (wet dog shakes, forelimb clonus, rearing, salivation). Rats treated with KA (0.3-10 nmol/rat) showed an almost identical behavioural profile. AMPA (1-10 nmol/rat)-induced convulsive behaviour was similar to DOM and KA only at the higher doses. NMDA (0.25-10 nmol/rat) caused clonic convulsions but not "status epilepticus". In mice, similar results were obtained: all the tested drugs induced generalized seizures, but only animals treated with DOM, KA and AMPA showed a prolonged sequence of seizures with forelimb clonus. Our results confirm the findings reported in the literature and support the hypothesis that DOM and KA act at the same EAA receptor.


Assuntos
Comportamento Animal/efeitos dos fármacos , Ácido Caínico/análogos & derivados , Animais , Ácido Ibotênico/administração & dosagem , Ácido Ibotênico/análogos & derivados , Ácido Ibotênico/toxicidade , Injeções Intraventriculares , Ácido Caínico/administração & dosagem , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos , N-Metilaspartato/administração & dosagem , N-Metilaspartato/toxicidade , Neurotoxinas/toxicidade , Ratos , Ratos Endogâmicos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
19.
Exp Brain Res ; 137(1): 1-11, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11310162

RESUMO

All forms of brain injury induce activation of astrocytes, although different types of injury induce different astrocytic responses. Activated astrocytes are characterised by hypertrophy, proliferation and increased expression of glial fibrillary acidic protein (GFAP). However, neither the process by which astrocytes become reactive nor the consequences are well understood. Recently, the application of specific growth factors to primary astrocytic cultures was shown to regulate dramatically the level of expression of the metabotropic glutamate receptors (mGluR) 5 and 3. In the present study, we have used an intracerebroventricular injection of a subconvulsive dose of kainic acid to produce a lesion of CA3a pyramidal neurones in the mouse hippocampus and to investigate whether mGluR expression was altered in reactive astrocytes in vivo. Immunohistochemical analysis showed strong mGluR5 and mGluR2/3 immunoreactivity in glial cells within the area of neuronal loss possessing the morphological feature of activated astrocytes. Double labelling with GFAP confirmed the expression of mGluRs by reactive astrocytes. The mechanical injury produced by the needle insertion in the cerebral cortex also produced enhanced expression of mGluR5 and mGluR2/3 in activated astrocytes proximal to the area of neuronal injury. Our finding of an increased mGluR expression in reactive astrocytes in vivo suggests that transcriptional regulation by specific growth factors on mGluRs is a phenomenon extendible to specific circumstances in vivo and not limited to in vitro models. Identification of the mechanisms of this adaptive plasticity will be central in the understanding of the events leading to neuronal survival and/or death.


Assuntos
Astrócitos/metabolismo , Lesões Encefálicas/metabolismo , Gliose/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Regulação para Cima/fisiologia , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/fisiologia , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Lesões Encefálicas/induzido quimicamente , Lesões Encefálicas/fisiopatologia , Células COS , Agonistas de Aminoácidos Excitatórios/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/induzido quimicamente , Gliose/fisiopatologia , Hipocampo/lesões , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Imuno-Histoquímica , Ácido Caínico/farmacologia , Masculino , Camundongos , Degeneração Neural/induzido quimicamente , Degeneração Neural/metabolismo , Degeneração Neural/fisiopatologia , Regeneração Nervosa/efeitos dos fármacos , Regeneração Nervosa/fisiologia , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Células Piramidais/efeitos dos fármacos , Células Piramidais/metabolismo , Células Piramidais/patologia , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
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