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1.
Cell Mol Neurobiol ; 30(4): 531-41, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19908141

RESUMO

In this study, we observed the effects of lipopolysaccharide (LPS) on neurodegeneration and immune response in the hippocampus. LPS is a gram-negative bacterial cell surface proteoglycan and known as a bacterial endotoxin. For this, we investigated the optimal concentration of LPS influencing the ICR mouse hippocampus to measure the LPS receptor, e.g., toll-like receptor 4 (TLR4), expression in mouse hippocampal homogenates. TLR4 expression was significantly and prominently increased in the hippocampal homogenates of the LPS (1 mg/kg)-treated group. Next, we examined pro-inflammatory response in the hippocampus using cyclooxygenase-2 (COX-2, a marker for inflammatory response) immunohistochemistry after LPS treatment. COX-2 immunoreactivity was significantly increased in the endothelium of blood vessels in the hippocampus 6 h after LPS treatment, judging from double immunofluorescence study with platelet-derived endothelial cell adhesion molecule-1 (PECAM-1, a marker for endothelial cells): it decreased 12 h and disappeared 24 h after LPS treatment. In addition, the ionized calcium-binding adapter molecule 1 (Iba-1)-immunoreactive ((+)) microglia were morphologically activated in the mouse hippocampus after LPS treatment. At 24 h after LPS treatment, Iba-1(+) microglia of activated forms were abundant in the hippocampus. However, NeuN (a neuron-specific soluble nuclear antigen)(+) neurons were not significantly changed in the hippocampus after LPS treatment. Fluoro-jade B (a marker for neuronal degeneration)(+) cells were not detected in the hippocampus at any time after LPS treatment. In addition, there were no significant differences in permeability of blood-brain barriers at any time points after LPS treatment. In brief, our results indicate that intraperitoneal administration of 1 mg/kg LPS effectively induces LPS receptor (TLR4) expression in the hippocampus, and the treatment increases corticosterone levels, inflammation in the blood vessels, and microglial activation in the hippocampus without any neuronal damage.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Endotélio/metabolismo , Hipocampo , Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Corticosterona/sangue , Proteínas de Ligação a DNA , Endotélio/citologia , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Imunidade Inata/fisiologia , Camundongos , Proteínas dos Microfilamentos , Microglia/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Permeabilidade , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Receptor 4 Toll-Like/metabolismo
2.
Cell Mol Neurobiol ; 30(1): 1-12, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19533334

RESUMO

Expression and age-related changes of calbindin-D28k (CB), parvalbumin (PV), and calretinin (CR) in the main olfactory bulb of the dog were investigated by immunohistochemistry and western blot analysis. Neurons that expressed these calcium-binding proteins showed a characteristic laminar distribution. Most of CB-immunoreactive neurons were observed in the glomerular layer (GL) and the inner sublayer of the external plexiform layer (EPL). Most of PV-immunoreactive neurons were observed in the outer sublayer of the EPL. CR-immunoreactive neurons were mainly distributed in the GL and the granule cell layer. With regard to age-related changes, CB-immunoreactive neurons in the GL were stable among all age groups; however, in the EPL they decreased with age. PV-immunoreactive neurons decreased in middle-aged and aged groups. However, CR-immunoreactive neurons were not decreased in middle-aged and aged groups. These results suggest that CB-immunoreactive neurons in the EPL were most sensitive to aging, and that their reduction may be related to aging in the dog.


Assuntos
Envelhecimento/metabolismo , Bulbo Olfatório/metabolismo , Parvalbuminas/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Animais , Western Blotting , Calbindina 2 , Calbindinas , Contagem de Células , Cães , Imuno-Histoquímica , Masculino , Neurônios/citologia , Neurônios/metabolismo , Bulbo Olfatório/citologia
3.
Cell Mol Neurobiol ; 29(5): 665-72, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19241154

RESUMO

The hippocampus is associated with learning and memory function and shows neurochemical changes in aging processes. Calbindin D-28k (CB) binds calcium ion with a fast association rate. We examined age-related changes in CB immunoreactivity and its protein level in the gerbil hippocampus during normal aging. In the hippocampal CA1 region (CA1) and CA2, CB immunoreaction was found in some neurons in the stratum pyramidale (SP) at postnatal month 1 (PM 1). CB immunoreactivity in neurons was markedly increased at PM 3. Thereafter, CB immunoreactivity was decreased with time: CB-immunoreactive ((+)) neurons were fewest at PM 24. In the CA3, a few CB(+) neurons were found only in the SP at PM 1 and in the stratum radiatum at PM 18 and 24. In addition, mossy fibers were stained with CB at PM 1. CB immunoreactivity in mossy fibers was markedly increased at PM 3, thereafter it was decreased with time. In the dentate gyrus, many granule cells (GC) in the granule cell layer were stained with CB at PM 1. CB immunoreactivity in GC was markedly increased at PM 3, thereafter CB immunoreactivity was decreased with time. In Western blot analysis, CB protein level in the gerbil hippocampus was highest at PM 3, thereafter CB protein levels were decreased with time. This result indicates that CB in the gerbil hippocampus is abundant at PM 3 and is decreased with age.


Assuntos
Envelhecimento/metabolismo , Gerbillinae/metabolismo , Hipocampo/metabolismo , Proteína G de Ligação ao Cálcio S100/imunologia , Animais , Western Blotting , Calbindinas , Giro Denteado/citologia , Giro Denteado/metabolismo , Hipocampo/citologia , Imuno-Histoquímica , Peso Molecular
4.
Neurochem Res ; 34(5): 851-8, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18758953

RESUMO

Diabetes is a metabolic disorder that is associated with the dysregulation of a number of systems within the body. In the present study, we investigated glucocorticoid receptor (GR) immunoreactivity and its protein levels in the paraventricular nuclei of 4-, 12-, 20- and 30-week-old Zucker diabetic fatty (fa/fa, ZDF) and in Zucker lean control (fa/+ or +/+, ZLC) rats, because the progressive induction of diabetes is detectable in this model after 7 weeks of age and chronic diabetic conditions are maintained after 12 weeks of age. GR immunoreactivity was detected in parvocellular paraventricular nuclei and this and GR protein levels were exponentially increased according to the ages. In particular, GR immunoreactivities and protein levels were markedly more increased in 30-week-old ZDF rats than in age-matched ZLC group and in younger ZDF group. The present study suggests that GR immunoreactivity and its protein level is associated with a degenerative phenotype in the hypothalamus of from 12-weeks old in the ZDF rat type II diabetes model.


Assuntos
Envelhecimento/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal , Diabetes Mellitus Tipo 2/fisiopatologia , Modelos Animais de Doenças , Feminino , Genótipo , Imuno-Histoquímica , Masculino , Mutação , Ratos , Ratos Zucker , Receptores para Leptina/genética
5.
Neurochem Res ; 34(6): 1039-46, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18982449

RESUMO

In the present study, we investigated the effects of a treadmill exercise on serum glucose levels and Ki67 and doublecortin (DCX) immunoreactivity, which is a marker of cell proliferation expressed during cell cycles except G0 and early G1 and a marker of progenitors differentiating into neurons, respectively, in the subgranular zone of the dentate gyrus (SZDG) using a type II diabetic model. At 6 weeks of age, Zucker lean control (ZLC) and Zucker diabetic fatty (ZDF) rats were put on a treadmill with or without running for 1 h/day/5 consecutive days at 22 m/min for 5 weeks. Body weight was significantly increased in the control (without running)-ZDF rats compared to that in the other groups. In the control groups blood glucose levels were increased by 392.7 mg/dl in the control-ZDF rats and by 143.3 mg/dl in the control-ZLC rats. However, in the exercise groups, blood glucose levels were similar between the exercise-ZLC and ZDF rats: The blood glucose levels were 110.0 and 118.2 mg/dl, respectively. Ki67 positive nuclei were detected in the SZDG in control and exercise groups. The number of Ki67 positive nuclei was significantly high in exercise groups compared to that in the control groups. In addition, Ki67 positive cells were abundant in ZLC groups compared to those in ZDF groups. DCX-immunoreactive structures in the control-ZDF rats were lower than that in the control-ZLC rats. In the exercise groups, DCX-immunoreactive structures (somata and processes with tertiary dendrites) and DCX protein levels were markedly increased in both the exercise-ZLC and ZDF rats compared to that in the control groups. These results suggest that a treadmill exercise reduces blood glucose levels in ZDF rats and increases cell proliferation and differentiation in the SZDG in ZLC and ZDF rats compared to those in control groups.


Assuntos
Giro Denteado/patologia , Diabetes Mellitus Tipo 2/patologia , Neurônios/patologia , Condicionamento Físico Animal , Animais , Biomarcadores/metabolismo , Glicemia/metabolismo , Peso Corporal , Diferenciação Celular , Divisão Celular , Proliferação de Células , Giro Denteado/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Ingestão de Alimentos , Teste de Esforço , Feminino , Interfase , Antígeno Ki-67/metabolismo , Leptina/genética , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Neurogênese , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Ratos , Ratos Zucker , Células-Tronco/metabolismo , Células-Tronco/patologia
6.
Neurochem Res ; 34(5): 964-72, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18850268

RESUMO

In the present study, we investigated the influences of a high fat diet (HD) fed for 12 weeks, on lipid peroxidation and antioxidant enzyme using 4-hydroxy-2E-nonenal (HNE)-modified proteins (HNE-mp) and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region (CA1) in C57BL/6N and C3H/HeN mice. Body weights and body weight gains were significantly higher in HD fed C57BL/6N mice than in low fat diet (LD) fed C57BL/6N and LD or HD fed C3H/HeN mice. In the HD fed C57BL/6N and C3H/HeN mice, HNE-mp immunoreactivity and protein levels were much higher than in the LD fed C57BL/6N or C3H/HeN mice. In particular, HNE-mp immunoreactivity and protein levels in HD fed C57BL/6N mice was higher than that in the HD fed C3H/HeN mice. SOD1 immunoreaction was detected in the non-pyramidal cells of C57BL/6N mice, while in the C3H/HeN mice SOD1 immunoreaction was observed in CA1 pyramidal cells. The SOD1 immunoreactivity in the LD fed C57BL/6N and C3H/HeN mice was slightly, but not significantly decreased compared to that in the HD fed C57BL/6N and C3H/HeN mice, respectively. In addition, ionized calcium-binding adapter molecule 1 (Iba-1) immunoreactive microglia in the HD fed C57BL/6N showed hypertrophy of cytoplasm, which is the characteristics of activated microglia. These results suggest that HD fed C57BL/6N mice are more susceptible to lipid peroxidation in the CA1 than in LD fed C57BL/6N and LD or HD fed C3H/HeN mice without any differences of SOD1 expression.


Assuntos
Aldeídos/metabolismo , Gorduras na Dieta/administração & dosagem , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Técnicas In Vitro , Peroxidação de Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos , Obesidade/genética , Obesidade/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Especificidade da Espécie , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1
7.
J Vet Med Sci ; 71(6): 753-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19578283

RESUMO

In this study, we observed and compared the effects of a high cholesterol diet (HCD) on cell proliferation and differentiation in the subgranular zone of the dentate gyrus of C57BL/6N (B6, susceptible strain) and C3H/HeN (C3H, resistant strain) mice. Ki67 (a marker for cell proliferation) positive cells) were significantly decreased in HCD-fed B6 mice compared to those in B6 (49.7%) and C3H mice fed a low cholesterol diet (LCD). In addition, doublecortin (DCX, a marker for cell differentiation or neuroblasts)-immunoreactive cells in HCD-fed B6 mice were significantly decreased compared to those in LCD-fed B6 and C3H mice. These results suggest that B6 strains are sensitive to HCD, which impairs cell proliferation and differentiation.


Assuntos
Colesterol na Dieta/administração & dosagem , Giro Denteado/citologia , Animais , Proliferação de Células/efeitos dos fármacos , Colesterol na Dieta/metabolismo , Giro Denteado/efeitos dos fármacos , Giro Denteado/metabolismo , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Feminino , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Neurogênese/fisiologia , Neuropeptídeos/metabolismo
8.
J Vet Med Sci ; 71(3): 275-80, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19346693

RESUMO

We investigated the effects of methimazole, an anti-thyroid drug, on the onset of type 2 diabetes in Zucker diabetic fatty (ZDF) rats. For this, 0.03% methimazole was administered to 7-week-old, pre-diabetic ZDF rats in drinking water for 5 weeks and the animals were sacrificed at 12 weeks of age. Methimazole treatment to ZDF rats significantly reduced blood glucose levels, food intake, body weight, and serum T3 levels. Hepatocytes in ZDF-methi rats were more densely stained with eosin than those in ZDF rats because of low fat accumulation in ZDF-methi hepatocytes. The pancreatic islet in ZDF-methi rats was normal compared to that in ZDF rats. Glucagon, not insulin, immunoreactivity in ZDF-methi rats was significantly higher than that in ZDF-methi rats. These suggest that methimazole treatment may delay the onset of type 2 diabetes in leptin receptor-deficient rats and also suggests that thyroid hormones may be necessary for the onset of diabetes.


Assuntos
Antitireóideos/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Metimazol/farmacologia , Receptores para Leptina/deficiência , Animais , Diabetes Mellitus Tipo 2/prevenção & controle , Feminino , Hepatócitos/metabolismo , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/complicações , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Ratos , Ratos Zucker , Receptores para Leptina/genética
9.
Neurochem Res ; 33(11): 2222-8, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18427987

RESUMO

Hippocampal interneurons are local circuit neurons which are responsible for inhibitory activity in the hippocampus. Parvalbumin (PV) is one of useful markers for GABAergic interneurons, not for principle cells, in the hippocampus. In the present study, we investigated age-related changes in PV immunoreactive neurons and protein levels in the gerbil hippocampus during normal aging. PV immunoreactive neurons were detected in all hippocampal subregions of all groups. PV immunoreactive neurons, which innervated principal neurons, were non-pyramidal neurons in the hippocampal CA1-3 regions, and were polymorphic neurons in the dentate gyrus. In the hippocampal CA1 region, the number of PV immunoreactive neurons was significantly reduced in the postnatal month 3 (PM 3) group, which was sustained by PM 18, and, at PM 24, the number of PV immunoreactive neurons was significantly decreased. In the CA2/3 region and dentate gyrus, the number of PV immunoreactive neurons was significantly decreased at PM 6: Thereafter, the number of PV immunoreactive neurons was sustained until PM 24. In addition, changes in PV protein levels in the gerbil hippocampus were similar to immunohistochemical changes during normal aging: PV protein levels were significantly decreased with age by PM 6: Thereafter, PV protein levels were sustained by PM 24. These results suggest that PV immunoreactive interneurons were decreased in the hippocampus with age in gerbils.


Assuntos
Envelhecimento/metabolismo , Parvalbuminas/metabolismo , Animais , Western Blotting , Giro Denteado/metabolismo , Gerbillinae , Imuno-Histoquímica , Masculino
10.
Neurosci Lett ; 431(3): 251-5, 2008 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-18166269

RESUMO

The hippocampus is a main brain region concerning learning and memory processes. It is imperative to determine the extent of alterations in number and function of inhibitory GABAergic interneurons in the hippocampus as a function of age. We examined changes in GABAergic neurons in the hippocampal CA1 region at various ages of dogs using glutamic acid decarboxylase 67 (GAD67), which is a rate-limiting enzyme for GABA synthesis. We found only one band in the brain homogenates in dogs as well as mice and rats. GAD67 immunoreactive neurons in 1-year-old dogs were mainly detected in the stratum oriens. In the 6-year-old group, GAD67 immunoreactive neurons were evenly distributed in the CA1 region, and numbers of the neurons were highest among all experimental groups. Thereafter, GAD67 immunoreactive neurons were significantly decreased region with age: GAD67 immunoreactive neurons were scarcely found in the CA1 region in 10-year-old dogs. The reduction of GAD67 immunoreactive neurons in the hippocampal CA1 region may be closely related to highly susceptibility to memory loss in old aged dogs.


Assuntos
Envelhecimento , Glutamato Descarboxilase/metabolismo , Hipocampo/citologia , Neurônios/enzimologia , Animais , Cães , Camundongos , Ratos
11.
J Vet Med Sci ; 70(3): 273-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18388427

RESUMO

Reactive oxygen species have been long associated with oxidative stress relevant to many pathological damages. In brain, 4-hydroxy-2E-nonenal (HNE), a major cytotoxic end product of lipid peroxidation, is produced. In contrast, superoxide dismutase (SOD), one of the major antioxidant enzymes, protects neurons from oxidative stress. The aim of this study is to observe differences in the distribution of HNE and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region of adult (2-3 years of age) and aged (10-12 years of age) dogs. The HNE immunoreactivity and protein level in the CA1 region were significantly high in the aged dogs compared to those in the adult dogs. SOD1 immunoreactivity and its protein level were also higher in the aged dogs than those in the adult dogs. However, there were not significant differences in NeuN (a neuron-specific soluble nuclear antigen) immunoreactivity in CA1 neurons between the adult and aged dogs. These differences may be associated with oxidative stress in aged dogs compared to that in adult dogs.


Assuntos
Aldeídos/metabolismo , Hipocampo/fisiologia , Peroxidação de Lipídeos/fisiologia , Estresse Oxidativo/fisiologia , Superóxido Dismutase/metabolismo , Fatores Etários , Animais , Western Blotting , Cães , Hipocampo/metabolismo , Coreia (Geográfico)
12.
J Vet Med Sci ; 70(6): 645-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18628612

RESUMO

We compared the immunoreactivity and numbers of tyrosine hydroxylase (TH) immunoreactive neurons and neuropil in the paraventricular nucleus (PVN) of the hypothalamus between the seizure sensitive (SS) and seizure resistant (SR) gerbils. The distributional pattern of TH immunoreactivity was similar in both groups: TH immunoreactivity was seen mainly in magnocellular neurons of the PVN. However, total TH immunoreactivity in the neurons and neuropil in the SS gerbils was significantly lower than that in the SR gerbils. In addition, the number of TH immunoreactive neurons in the SS gerbils was also much lower than those in the SR gerbils. These results indicate that SS gerbils have a low TH immunoreactivity in the hypothalamic PVN compared with that in SR gerbils.


Assuntos
Gerbillinae/metabolismo , Neurônios/imunologia , Núcleo Hipotalâmico Paraventricular/enzimologia , Convulsões/metabolismo , Tirosina 3-Mono-Oxigenase/imunologia , Animais , Suscetibilidade a Doenças , Peróxido de Hidrogênio , Soros Imunes/imunologia , Soros Imunes/metabolismo , Neurônios/metabolismo , Convulsões/genética , Tirosina 3-Mono-Oxigenase/metabolismo
13.
J Vet Med Sci ; 70(4): 343-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18460827

RESUMO

We examined the age-related changes of calbindin D-28k (CB)-immunoreactive neurons and overall populations of neurons in the myenteric plexus of gerbil duodenum using whole mount preparations and immunohistochemistry. The circumference of duodenum increased age-dependently. CB-immunoreactive neurons were observed in all groups, and most of them had the Dogiel type II morphology. The fully developed cobweb-like structures were observed in the myenteric plexus of duodenum at postnatal month (PM) 3 to 24. Although the highest numbers of CB-immunoreactive neurons and overall population were observed in PM 1.5, it is related with significant increase of the size of circumference between PM 1.5 to PM 3. CB-immunoreactive neurons were slightly decreased with age between PM 3 to PM 24. We have also found that whole numbers of myenteric neurons were also significantly decreased in PM 24 group. These results suggest that loss of overall numbers of myenteric neurons and CB-immunoreactive neurons may be related with age-related neurodegeneration and functional loss of duodenum in the gerbil.


Assuntos
Duodeno/inervação , Gerbillinae/metabolismo , Plexo Mientérico/citologia , Neurônios/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Envelhecimento , Animais , Calbindinas , Regulação da Expressão Gênica , Masculino , Proteína G de Ligação ao Cálcio S100/genética
14.
J Vet Med Sci ; 70(12): 1405-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19122416

RESUMO

In the present study, we compared differences in ionized calcium-binding adapter molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) immunoreactivities for microglia and astrocytes, respectively, in the hippocampus of the seizure-resistant (SR) and seizure-sensitive (SS) gerbils. The density of Iba-1 immunoreactive microglia in the hippocampal CA1 region (CA1) and dentate gyrus (DG) of the SS gerbil was higher than that in the SR gerbil, and many Iba-1 immunoreactive microglia in the SS gerbil were hypertrophied in morphology. In contrast, we could not find significant difference in the density of GFAP immunoreactive astrocytes between the SR and SS gerbils. This result indicates that Iba-1 immunoreactive microglia in CA1 and DG of the SS gerbil are activated compared to those in the SR gerbil.


Assuntos
Astrócitos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Gerbillinae/fisiologia , Hipocampo/metabolismo , Microglia/metabolismo , Convulsões/metabolismo , Animais , Biomarcadores , Proteínas de Ligação ao Cálcio , Regulação da Expressão Gênica
15.
J Vet Med Sci ; 70(9): 965-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18840972

RESUMO

Astrocytes perform neuron-supportive tasks, repair and scarring process in the central nervous system. In this study, we observed glial fibrillary acidic protein (GFAP), a marker for astrocytes, immunoreactivity in the dentate gyrus and hippocampus proper (CA1-3 region) of adult (2-3 years of age) and aged (10-12 years of age) dogs. In the adult group, GFAP immunoreactive astrocytes were distributed in all layers of the dentate gyrus and CA1-3 region, except in the stratum pyramidale of the CA1-3 region. In the aged group, GFAP immunoreactivity decreased markedly in the molecular layer of the dentate gyrus. However, GFAP immunoreactivity in the CA1-3 region increased in all layers, and the cytoplasm of GFAP immunoreactive astrocytes was hypertrophied. GFAP protein levels in the aged dentate gyrus decreased; however, GFAP levels in the CA1-3 region increased. These results suggest that the morphology of astrocytes and GFAP protein levels in the hippocampal dentate gyrus and CA1 region are changed, respectively, with age.


Assuntos
Astrócitos/citologia , Astrócitos/metabolismo , Giro Denteado/metabolismo , Cães/imunologia , Proteína Glial Fibrilar Ácida/metabolismo , Fatores Etários , Animais , Western Blotting , Imuno-Histoquímica
16.
J Vet Med Sci ; 70(4): 373-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18460832

RESUMO

Spontaneously hypertensive rats (SHRs) are widely accepted in medical research because this model has been used for studies in neurodegenerative diseases such as vascular dementia and stroke. In the present study, we observed newly generated neuronal precursors using doublecortin (DCX, a marker of neural proliferation and differentiation) in the subgranular zone of the dentate gyrus in SHRs compared to Sprague-Dawley rats (SDRs) at various age stages. DCX immunoreactivity, immunoreactive cell numbers and its protein level in the dentate gyrus of the SHRs were higher than those in the SDRs at postnatal month 1 (PM 1). At PM 8, DCX immunoreactivity, immunoreactive cell numbers and protein levels in both groups were markedly decreased compared to those at PM 1; however, they were higher than those in the SDRs. They were decreased in the both groups with age: DCX immunoreactive cells in the SDRs were few at PM 12. Our results indicate that newly generated neuronal precursors are more abundant in SHRs than in SDRs during their life.


Assuntos
Giro Denteado/citologia , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/citologia , Neuropeptídeos/metabolismo , Animais , Giro Denteado/metabolismo , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Imuno-Histoquímica , Masculino , Neurônios/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley
17.
J Vet Med Sci ; 69(11): 1131-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18057827

RESUMO

Microglia are evenly distributed throughout the brain parenchyma. They respond rapidly to a variety of alterations in the microenvironment of the brain and act as sensors for pathological events in the brain. In the present study, we investigated the age-dependent changes in the immunoreactivity and protein level of ionized calcium-binding adapter molecule 1 (Iba-1), a microglial marker, in the CA1 region of the gerbil hippocampus. Iba-1 immunoreactive microglia were detected in the hippocampal CA1 region of the postnatal month 1 (PM 1) group. Iba-1 positive microglia were morphologically inactive between the PM 1 and PM 12 stages. Some Iba-1 immunoreactive microglia were present in the active form in the hippocampal CA1 region of the PM 18 and PM 24 groups. The Iba-1 protein levels in hippocampal CA1 homogenates were decreased in the PM 1 through PM 6 groups and increased in an age-dependent manner thereafter. These results suggest that Iba-1 immunoreactive microglia in the active form were detected in the hippocampal CA1 region in the PM 18 and PM 24 groups. This result may be associated with an age-dependent susceptibility to neurodegenerative diseases associated with the hippocampus.


Assuntos
Envelhecimento/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Gerbillinae/metabolismo , Hipocampo/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/imunologia , Regulação da Expressão Gênica , Hipocampo/anatomia & histologia , Imuno-Histoquímica , Masculino
18.
Neurosci Res ; 54(4): 319-27, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16473422

RESUMO

In the present study, we observed expression and changes of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the gerbil hippocampal CA1 region, but not in the CA2/3 region, after 5 min of transient forebrain ischemia. In blood, corticosterone levels were increased biphasically at 30 min and 12 h after ischemia/reperfusion, and thereafter its levels were decreased. In the sham-operated group, MR and GR immunoreactivities were weakly detected in the CA1 region. By 3 days after ischemia, MR and GR were not significantly altered in the CA1 region: at 12 h after ischemia, GR was expressed in a few neurons in the CA1 region, whereas MR was not expressed in any neurons after ischemic insult. From 4 days after ischemia, MR and GR immunoreactivities were detected in astrocytes and microglia in the CA1 region, and at 7 days after ischemia, MR and GR immunoreactivities peaked in the hippocampal CA1 region. At this time, 55% of astrocytes and 30% of microglia showed MR immunoreactivity, and 20% of astrocytes and 40% of microglia showed GR immunoreactivity. Western blot analyses showed that the pattern of changes in MR and GR protein levels was similar to the immunohistochemical changes observed after transient forebrain ischemia. From 4 days after ischemia, MR and GR protein levels were increased time-dependently after ischemia. In conclusion, enhanced MR and GR expressions in astrocytes and microglia were detected in the hippocampal CA1 region 4-7 days after ischemia/reperfusion. At this time, GR immunoreactivity was abundant in microglia, whereas MR immunoreactivity was prominent in astrocytes. The specific distribution of corticosteroid receptors in the astrocytes and microglia may be associated with the differences of MR and GR functions against ischemic damage.


Assuntos
Astrócitos/metabolismo , Hipocampo/metabolismo , Ataque Isquêmico Transitório/metabolismo , Microglia/metabolismo , Receptores de Glucocorticoides/biossíntese , Receptores de Mineralocorticoides/biossíntese , Animais , Morte Celular , Gerbillinae , Imuno-Histoquímica , Ataque Isquêmico Transitório/patologia , Masculino , Neurônios/patologia
19.
J Vet Med Sci ; 68(5): 465-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16757889

RESUMO

The changes of calretinin (CR)-immunoreactive periglomerular cells in the glomerular layer of the main olfactory bulb (MOB) were investigated in rats differing ages from postnatal month 1 (PM 1) to PM 24. The number of cresyl violet-positive periglomerular cells was similar between PM 1 and PM 12, but they decreased slightly in the PM 24 group. The size of CR-immunoreactive periglomerular cells in the glomerular layer increased with age, while their numbers did not change significantly in the PM 6-PM 24 groups. In the PM 24 group, numbers of CR-positive periglomerular cell bodies and their processes decreased, while the size of CR-positive cell bodies in the glomeruli was larger than that of the previous groups. These results suggest that CR-immunoreactive periglomerular cells in the rat MOB are well-developed in the PM 6 group, and that periglomerular cells in the PM 24 group show poor CR-immunoreactivity compared to those in the PM 6 group.


Assuntos
Envelhecimento/metabolismo , Bulbo Olfatório/citologia , Bulbo Olfatório/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Animais , Calbindina 2 , Imuno-Histoquímica , Masculino , Bulbo Olfatório/anatomia & histologia , Ratos , Ratos Sprague-Dawley
20.
J Neurol Sci ; 239(1): 59-66, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16140342

RESUMO

This study was carried out to investigate alterations of neurofilament 200 kDa (NF-200) and its polyphosphorylation form (RT97) immunoreactivity and protein content in the main olfactory bulb (MOB) after 5 min of transient forebrain ischemia in gerbils. In the sham-operated group, weak NF-200 immunoreactivity was detectable in a few somata of mitral cells, which projected weak NF-200-immunoreactive processes to the external plexiform layer (EPL). At 1-5 days after ischemia, strong NF-200 and RT97 immunoreactivity was shown by the mitral cell processes; however, somata of mitral cells did not show NF-200 immunoreactivity. At this time point, strong NF-200-immunoreactive mitral cell processes ran to the EPL and glomerular layer (GL). Thereafter, NF-200 and RT97 immunoreactivity was decreased up to 30 days after ischemia. In the 15 days post-ischemic group, the distribution pattern of NF-200 and RT97 immunoreactivity was slightly lower than that in the 1-5 days post-ischemic groups. In the 30 days post-ischemic group, moderate NF-200 and RT97 immunoreactivity was found in the mitral cells processes, but the immunoreactivity in the EPL and GL nearly disappeared. A Western blot study showed a pattern of NF-200 and RT97 expression at all post-ischemic time points similar to that of immunohistochemistry after ischemia. This result indicates that NF-200 and RT97 accumulates in injured mitral cell processes a few days after transient ischemia, which suggests that the axonal transport in the MOB may be disturbed during this period after transient ischemia.


Assuntos
Isquemia Encefálica/metabolismo , Ataque Isquêmico Transitório/metabolismo , Proteínas de Neurofilamentos/metabolismo , Bulbo Olfatório/metabolismo , Animais , Transporte Axonal/fisiologia , Axônios/imunologia , Axônios/patologia , Western Blotting , Isquemia Encefálica/fisiopatologia , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Modelos Animais de Doenças , Gerbillinae , Imuno-Histoquímica , Ataque Isquêmico Transitório/fisiopatologia , Masculino , Neurônios/imunologia , Neurônios/patologia , Neurópilo/imunologia , Neurópilo/patologia , Bulbo Olfatório/patologia , Bulbo Olfatório/fisiopatologia , Condutos Olfatórios/imunologia , Condutos Olfatórios/patologia , Condutos Olfatórios/fisiopatologia , Fosforilação , Proteínas/análise , Proteínas/metabolismo , Fatores de Tempo
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