RESUMO
While previous studies and brain atlases divide the hypothalamus into many nuclei and areas, uncharacterised regions remain. Here, we report a new region in the mouse anterior hypothalamus (AH), a triangular-shaped perifornical area of the anterior hypothalamus (PeFAH) between the paraventricular hypothalamic nucleus and fornix, that abundantly expresses chondroitin sulfate proteoglycans (CSPGs). The PeFAH strongly stained with markers for chondroitin sulfate/CSPGs such as Wisteria floribunda agglutinin and antibodies against aggrecan and chondroitin 6 sulfate. Nissl-stained sections of the PeFAH clearly distinguished it as a region of comparatively low density compared to neighboring regions, the paraventricular nucleus and central division of the anterior hypothalamic area. Immunohistochemical and DNA microarray analyses suggested that PeFAH contains sparsely distributed calretinin-positive neurons and a compact cluster of enkephalinergic neurons. Neuronal tract tracing revealed that both enkephalin- and calretinin-positive neurons project to the lateral septum (LS), while the PeFAH receives input from calbindin-positive LS neurons. These results suggest bidirectional connections between the PeFAH and LS. Considering neuronal subtype and projection, part of PeFAH that includes a cluster of enkephalinergic neurons is similar to the rat perifornical nucleus and guinea pig magnocellular dorsal nucleus. Finally, we examined c-Fos expression after several types of stimuli and found that PeFAH neuronal activity was increased by psychological but not homeostatic stressors. These findings suggest that the PeFAH is a source of enkephalin peptides in the LS and indicate that bidirectional neural connections between these regions may participate in controlling responses to psychological stressors.
Assuntos
Núcleo Hipotalâmico Anterior/citologia , Núcleo Hipotalâmico Anterior/metabolismo , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Núcleos Septais/citologia , Núcleos Septais/metabolismo , Agressão/fisiologia , Animais , Encefalinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , Atividade Motora , Rede Nervosa/citologia , Rede Nervosa/metabolismo , Vias Neurais/citologia , Vias Neurais/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos , Restrição Física , Estresse Psicológico/metabolismoRESUMO
Chondroitin sulfate proteoglycans (CSPGs) are major components of the extracellular matrix (ECM) in the brain. In adult mammals, CSPGs form the specialized ECM structure perineuronal nets (PNNs) that surround somata and dendrites of certain types of neurons. PNNs restrict synaptic plasticity and regulate the closure of critical periods. Although previous studies have examined the starting period of PNN formation, focusing on primary sensory cortices, there are no systematic studies at the whole brain level. Here, we examined the starting period of PNN formation in male mice ranging in age from postnatal day 3 to week 11, mainly focusing on several cortical areas, limbic structures, hypothalamus, and brain stem, using lectin histochemistry with Wisteria floribunda agglutinin (WFA). Results showed that early PNN formation was observed in several reticular formations of the brain stem related to the cranial nerves and primary somatosensory cortices. In the limbic system, PNN formation in the hippocampus started earlier than that of the amygdala. Furthermore, in the medial amygdaloid nucleus and some hypothalamic regions, WFA labeling did not show typical PNN-like forms. The present study suggests spatiotemporal differences at the beginning of PNN formation and a structural variety of CSPG-contained ECM in the brain.
Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Sulfatos de Condroitina/metabolismo , Matriz Extracelular/metabolismo , Animais , Tronco Encefálico/crescimento & desenvolvimento , Tronco Encefálico/metabolismo , Hipotálamo/crescimento & desenvolvimento , Hipotálamo/metabolismo , Sistema Límbico/crescimento & desenvolvimento , Sistema Límbico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismoRESUMO
Adverse experiences in early life can affect the formation of neuronal circuits during postnatal development and exert long-lasting influences on neural function. Many studies have shown that daily repeated maternal separation (RMS), an animal model of early life stress, can modulate the hypothalamic-pituitary-adrenal axis (HPA-axis) and can affect subsequent brain function and emotional behavior during adulthood. However, the molecular basis of the long-lasting effects of early life stress on brain function has not been completely elucidated. In this mini-review, we introduce various cases of maternal separation in rodents and illustrate the alterations in HPA-axis activity by focusing on corticosterone (CORT), an end-product of the HPA-axis in rodents. We then present the characterization of the brain regions affected by various patterns of MS, including RMS and single time maternal separation (SMS) at various stages before weaning, by investigating c-Fos expression, a biological marker of neuronal activity. These CORT and c-Fos studies suggest that repeated early life stress may affect neuronal function in region- and temporal-specific manners, indicating a critical period for habituation to early life stress. Furthermore, we introduce changes in behavioral aspects and gene expression in adult mice exposed to RMS.
Assuntos
Encéfalo/metabolismo , Encéfalo/fisiologia , Estresse Psicológico/metabolismo , Estresse Psicológico/fisiopatologia , Animais , Animais Recém-Nascidos , Corticosterona/metabolismo , Feminino , Camundongos , Proteínas Proto-Oncogênicas c-fos/metabolismoRESUMO
Adverse experience in early life can affect the formation of neuronal circuits during postnatal development and exert long-lasting influences on neural functions that can lead to the development of a variety of psychiatric disorders including depression, anxiety disorders, and post-traumatic stress disorder. Many studies have demonstrated that daily repeated maternal separation, an animal model of early-life stress, can induce impairments in emotional behaviours and cognitive function during adolescence and adulthood. However, the behavioural phenotypes of maternally separated mice under long-term group-housing conditions are largely unknown. In this study, we applied our newly developed assay system to investigate the effects of maternal separation on behaviours under group-housing conditions during four days of continuous observations. Using our system, we found that repeated maternal separation resulted in inappropriate social distance from cagemates, altered approach preferences to others, and induced a lower rank in the time spent on the running wheel under group-housing conditions in adult male mice. Focussing on these behavioural abnormalities that appear in an environment with a social context will be important insights to understand the pathogenesis of psychiatric disorders.
Assuntos
Comportamento Animal , Abrigo para Animais , Privação Materna , Camundongos Endogâmicos C57BL/psicologia , Comportamento Social , Meio Social , Animais , MasculinoRESUMO
The hypothalamus controls metabolism, stress responses, and instinctive behaviors for individual survival and species preservation. Recent studies suggest that hypothalamic neurons retain plasticity throughout adulthood, which enables these neurons to respond to various kinds of changes in environment, nutrients, and fluctuating hormones. One of the mechanisms underlying the regulation of neural plasticity is the formation of a stable extracellular matrix (ECM) structure called perineuronal nets (PNNs). PNNs are large aggregates of heterogeneous ECM molecules such as chondroitin sulfate proteoglycans (CSPGs), hyaluronan, their link proteins, and tenascin-R. PNNs surround the cell body and proximal dendrites of a subset of neurons and limit adult neural plasticity. This review describes the CSPG-based ECM, including the PNNs, with a special focus on the hypothalamus of mice. We first provide an overview of PNNs in terms of their structure, molecular components, and functions, most of which have been demonstrated by extrahypothalamic studies. Second, we show the presence or absence of PNNs within individual hypothalamic regions and then describe non-PNN-formed ECM containing CSPGs that can be observed in particular hypothalamic regions. Finally, we will introduce a newly identified mouse hypothalamic area that we named the perifornical area of the anterior hypothalamus (PeFAH), which contains a cluster of PNN-positive neurons. PeFAH neurons express enkephalin and have bidirectional connections with the lateral septum. The anterior hypothalamus and lateral septum are thought to regulate defensive behaviors; therefore, the PeFAH neurons and PNNs around them could be involved in the regulation of defensive behaviors.
Assuntos
Matriz Extracelular/metabolismo , Matriz Extracelular/fisiologia , Hipotálamo Anterior/citologia , Hipotálamo Anterior/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Animais , Comportamento Animal , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Proteoglicanas de Sulfatos de Condroitina/fisiologia , Proteoglicanas de Sulfatos de Condroitina/ultraestrutura , Mecanismos de Defesa , Encefalinas/metabolismo , Matriz Extracelular/ultraestrutura , Hipotálamo Anterior/metabolismo , Camundongos Endogâmicos C57BL , Plasticidade NeuronalRESUMO
Early-life stress has long-lasting effects on the stress response, emotions, and behavior throughout an individual's life. Clinical reports have demonstrated that child abuse victims exhibit impairments in reward-associated behavior; yet, the mechanism for this effect remains unclear. Maternal separation (MS) or MS coupled with social isolation (SI) (MS+SI) is widely used as a model for early-life stress in rodent studies. We employed mice subjected to MS+SI to clarify the long-term effect of early-life stress on reward-seeking involving palatable foods by a conditioned place-preference (CPP) paradigm. Prior MS+SI experience decreased exploration time in a chocolate-paired compartment in adult female mice, but not in male mice. We then focused on the mesolimbic dopamine pathway associated with reward-seeking behavior and measured both mRNA and protein levels of tyrosine hydroxylase (TH) in the ventral tegmental area (VTA) and dopamine D1 and D2 receptors in the nucleus accumbens (NAc). MS+SI female mice had significantly lower D1 receptor mRNA and protein levels than controls, whereas the expression of TH and the D2 receptor was similar in the 2 groups. All mRNA and protein levels were unchanged in MS+SI male mice. When attempting to elucidate the mechanism underlying downregulation of the D1 receptor in the NAc of MS+SI females, we found hypermethylation of the Drd1a promoter region. These results suggest that early-life stress affects reward-seeking behavior in female mice, which may be associated with the downregulation of D1 receptor in the NAc via epigenetic modification of its promoter region.
Assuntos
Metilação de DNA , Privação Materna , Núcleo Accumbens/metabolismo , Receptores de Dopamina D1/metabolismo , Recompensa , Isolamento Social , Animais , Feminino , Masculino , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Receptores de Dopamina D1/genética , Fatores SexuaisRESUMO
OBJECTIVE Transplantation of bone marrow stromal cells (BMSCs) is a theoretical potential as a therapeutic strategy in the treatment of spinal cord injury (SCI). Although a scaffold is sometimes used for retaining transplanted cells in damaged tissue, it is also known to induce redundant immunoreactions during the degradation processes. In this study, the authors prepared cell sheets made of BMSCs, which are transplantable without a scaffold, and investigated their effects on axonal regeneration, glial scar formation, and functional recovery in a completely transected SCI model in rats. METHODS BMSC sheets were prepared from the bone marrow of female Fischer 344 rats using ascorbic acid and were cryopreserved until the day of transplantation. A gelatin sponge (GS), as a control, or BMSC sheet was transplanted into a 2-mm-sized defect of the spinal cord at the T-8 level. Axonal regeneration and glial scar formation were assessed 2 and 8 weeks after transplantation by immunohistochemical analyses using anti-Tuj1 and glial fibrillary acidic protein (GFAP) antibodies, respectively. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan scale. RESULTS The BMSC sheets promoted axonal regeneration at 2 weeks after transplantation, but there was no significant difference in the number of Tuj1-positive axons between the sheet- and GS-transplanted groups. At 8 weeks after transplantation, Tuj1-positive axons elongated across the sheet, and their numbers were significantly greater in the sheet group than in the GS group. The areas of GFAP-positive glial scars in the sheet group were significantly reduced compared with those of the GS group at both time points. Finally, hindlimb locomotor function was ameliorated in the sheet group at 4 and 8 weeks after transplantation. CONCLUSIONS The results of the present study indicate that an ascorbic acid-induced BMSC sheet is effective in the treatment of SCI and enables autologous transplantation without requiring a scaffold.
Assuntos
Transplante de Medula Óssea , Células-Tronco Mesenquimais/citologia , Regeneração Nervosa/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismos da Medula Espinal/terapia , Animais , Axônios/patologia , Transplante de Medula Óssea/métodos , Diferenciação Celular/fisiologia , Modelos Animais de Doenças , Feminino , Transplante de Células-Tronco Mesenquimais/métodos , Neuroglia/patologia , Ratos Endogâmicos F344 , Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologiaRESUMO
OBJECTIVES: Oxidative stress induces cellular responses such as cell death, gene activation and cell proliferation, in the liver. Vitamin E (Vit. E) has been found to protect the liver against oxidative stress in animal experiments. Thioredoxin (TRX) is a stress inducible, multifunctional protein, secreted during oxidative stress. This study evaluated effects of Vit. E on serum TRX and aminotransferase levels in hepatitis C virus (HCV) patients, partly non-responsive to initial interferon (IFN), with higher than average level of serum alanine aminotransferase (ALT) after receiving anti-inflammatory drug treatment. METHODS: Seventeen HCV patients (male = 3; female = 14) of age 62 +/- 7.65 years receiving anti-inflammatory drug therapy, at least 6 months prior to Vit. E administration, were given d-alpha-tocopherol 500 mg/day, orally, for a period of 3 months. ALT, aspartate aminotransferase (AST), TRX and Vit. E were measured at 0, 1, 2 and 3 months and 1 month after end of treatment. As controls, the same patients biochemical data, 3 months from the start of therapy were used. Patients were divided into three categories: total patients "T", low ALT group "L" (ALT < 70 IU/l) and high ALT group "H" (ALT > 70 IU/l), respectively. RESULTS: The ALT level was lowered, significantly in group H, in the 1st, 2nd, 3rd and 1-month post therapy, compared to the initial value. But group L showed little or no change in ALT. Post Vit. E therapy, in groups T and H, the TRX level was elevated but remained below initial levels, whereas in group L, TRX level remained significantly lower than the pretreatment value. Groups T and L, showed significant reduction (p < 0.05) in serum TRX levels in the 2nd and 3rd month. Group H showed a tendency towards TRX reduction, but not significantly. Serum Vit. E levels increased significantly (p < 0.0001) from the 1st to 3rd month in all three T, H and L groups. CONCLUSION: Oxidative stress induced liver damage is reduced by Vit. E in patients with viral hepatitis C, particularly those with initial ALT levels > 70 IU/l. Vit. E treatment causes reduction of oxidative stress markers as TRX and ALT in sera. Therefore, Vit. E can act as a supportive therapy to combat liver damage caused by oxidative stress, in such patients with continuously high levels of ALT even after anti-viral and anti-inflammatory drug therapy.
Assuntos
Alanina Transaminase/sangue , Hepatite C/sangue , Tiorredoxinas/sangue , Vitamina E/farmacologia , Idoso , Feminino , Hepatite C/enzimologia , Humanos , Interferons/farmacologia , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Fatores de Tempo , Vitamina E/metabolismo , alfa-Tocoferol/farmacologiaRESUMO
OBJECTIVES: An abnormal fatty acid pattern in patients with advanced liver cirrhosis (LC) has been reported in plasma phospholipids and some other tissues. To elucidate the significance of arachidonic acid deficiency on the clinical pathophysiology of LC and hepatocellular carcinoma (HCC), we analyzed the fatty acid compositions of mononuclear cell phospholipids, plasma alpha-tocopherol, and thiobarbituric acid-reactive substances and serum tumor necrosis factor-alpha (TNF-alpha) in cirrhotic patients infected with the hepatitis C virus with and without HCC. METHODS: Twelve cirrhotic patients without HCC (LC patients) and 11 with HCC (HCC patients) were enrolled. Fatty acids were analyzed with gas chromatography. alpha-Tocopherol and TNF-alpha were analyzed by high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. Statistical analysis was performed by using the unpaired t test with Welch's correction and Spearman's rank-correlation analysis. RESULTS: Significantly low levels of linoleic, dihomo-gamma-linolenic, arachidonic, and eicosapentaenoic acids from mononuclear cell phospholipids were observed in LC and HCC patients compared with control subjects. Plasma alpha-tocopherol was lower and thiobarbituric acid-reactive substances were higher in HCC patients than in controls. Arachidonic acid molar percentage in mononuclear cell phospholipids correlated significantly with lymphocyte count (r = 0.460, P < 0.05) in the cirrhotic patients and with lymphocyte (r = 0.680, P < 0.01) and platelet (r = 0.763, P < 0.01) counts in all subjects. CONCLUSIONS: These results suggested that arachidonic acid in mononuclear cells may have an important role in the pathophysiology of hepatitis C virus associated with cirrhosis and that nutritional management preventing arachidonic acid deficiency may have some beneficial effects on the progression of LC.
Assuntos
Ácido Araquidônico/deficiência , Carcinoma Hepatocelular/sangue , Hepatite C/complicações , Leucócitos Mononucleares/química , Cirrose Hepática/sangue , Neoplasias Hepáticas/sangue , Idoso , Ácido Araquidônico/análise , Estudos de Casos e Controles , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Ácidos Graxos/sangue , Feminino , Hepatite C/sangue , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Fosfolipídeos/química , Contagem de Plaquetas , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Fator de Necrose Tumoral alfa/análise , alfa-Tocoferol/análise , alfa-Tocoferol/sangueRESUMO
OBJECTIVE: We compared the habitual food intake and plasma fatty acid composition in cirrhotic patients living in two different regions in Japan, Okayama and Toyama, and evaluated the effects of dietary polyunsaturated fatty acid and alpha-tocopherol intake on serum alanine aminotransferase (ALT) activity. METHOD: A quantitative food-frequency questionnaire method was used. RESULTS: The significantly higher intake of fish in the patients living in Toyama resulted in higher plasma levels of docosahexaenoic acid and lower levels of arachidonic acid. Serum ALT activity correlated negatively with plasma arachidonic acid (r = -0.456, P < 0.05) and alpha-tocopherol (r = -0.505, P < 0.05) levels. Dietary intakes of vitamin E and polyunsaturated fatty acids (mg/g) correlated negatively with serum ALT (r = -0.377, P < 0.05). Dietary intake of linoleic acid and the ratio of polyunsaturated to saturated fatty acid in dietary fat correlated significantly with serum ALT (r = 0.604, P < 0.01, and r = 0.622, P < 0.01, respectively). The amount of vegetable intake correlated with intake of vitamin E and polyunsaturated fatty acid (r = 0.527, P < 0.02). CONCLUSIONS: These findings suggest that habitual food intake affects the plasma fatty acid profile and that elevated serum ALT may be related to arachidonic acid deficiency and vulnerability to lipid peroxidation in cirrhotic patients with hepatitis B and C viruses.
Assuntos
Ingestão de Alimentos/fisiologia , Ácidos Graxos Insaturados/deficiência , Comportamento Alimentar/fisiologia , Cirrose Hepática/complicações , Alanina Transaminase/sangue , Antioxidantes/análise , Ácidos Graxos Insaturados/sangue , Feminino , Humanos , Japão , Cirrose Hepática/sangue , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , alfa-Tocoferol/sangueRESUMO
OBJECTIVE: We investigated the effects of vitamin E supplementation on the fatty acid composition of red blood cell membrane phospholipids and on the clinical observations in patients with hepatitis C virus. METHOD: Eight patients and control subjects were administered 500 mg/d of d-alpha-tocopherol for 12 wk. The alpha-tocopherol and fatty acid composition of phospholipids in red blood cells were analyzed before, at 4, 8, and 12 wk, and after 4 wk of washout of vitamin E administration. RESULTS: The alpha-tocopherol concentration in red blood cells increased 2.37-fold of the basal level during vitamin E supplementation. Serum alanine aminotransferase levels increased in five of eight patients with vitamin E supplementation. The arachidonic acid level, docosahexaenoic acid level, and ratio of polyunsaturated to saturated fatty acid in red blood cell membrane phospholipids, which were significantly lower in the patients than in the control subjects, were elevated at 8 and 12 wk after vitamin E supplementation. The improvement in fatty acid composition was observed particularly in the patients who responded to the vitamin E therapy. CONCLUSIONS: Vitamin E therapy for the prevention of disease progression in patients with hepatitis C virus may be effective.
Assuntos
Membrana Eritrocítica/química , Ácidos Graxos Insaturados/sangue , Hepatite C/sangue , alfa-Tocoferol/administração & dosagem , Alanina Transaminase/sangue , Ácido Araquidônico/sangue , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfolipídeos/sangueRESUMO
During postnatal development, adverse early life experiences affect the formation of neuronal networks and exert long-lasting effects on neural function. Many studies have shown that daily repeated maternal separation (MS), an animal model of early life stress, can regulate the hypothalamic-pituitary-adrenal axis (HPA axis) and affect subsequent brain function and behavior during adulthood. However, the molecular basis of the long-lasting effects of early life stress on brain function has not been fully elucidated. In this mini review, we present various cases of MS in rodents and illustrate the alterations in HPA axis activity by focusing on corticosterone (CORT). We then show a characterization of the brain regions affected by various patterns of MS, including repeated MS and single time MS at various stages before weaning, by investigating c-Fos expression. These CORT and c-Fos studies suggest that repeated early life stress may affect neuronal function in region- and temporal-specific manners, indicating a critical period for habituation to early life stress. Next, we introduce how early life stress can impact behavior, namely by inducing depression, anxiety or eating disorders, and alterations in gene expression in adult mice subjected to MS.