RESUMO
The retinotectal topography of rats develops within the first three postnatal weeks during the critical period. Previous studies have shown that monocular enucleation results in plasticity of the intact retinotectal pathway in a time-dependent manner. Glial fibrillary acidic protein (GFAP), an astrocyte marker, is up-regulated after central nervous system injury. Adenosine is a neuromodulator involved in the development and plasticity of the visual system acting through the inhibitory A1 and excitatory A2a receptor activities. Herein, we examined whether adenosine receptors and astrocytes are crucial for monocular enucleation (ME)-induced plasticity. We also investigate whether A2a blockade alters retinotectal plasticity in an astrocyte-dependent manner. Lister Hooded rats were submitted to monocular enucleation at postnatal day 10 (PND10) or PND21 and, after different survival times, were processed for immunohistochemistry or western blotting assays. Another group underwent subpial implantation of ELVAX containing vehicle (DMSO) or SCH58261 (1 µM - an A2a receptor antagonist), simultaneously with ME at PND10. After a 72 h survival, GFAP content and the retinotectal plasticity were evaluated. Our data show that monocular enucleation leads to an upregulation in GFAP expression in the contralateral superior colliculus. At PND10, a slight increase in GFAP labeling was observed at 72 h post-enucleation, while at PND21 GFAP increase was detected in the deafferented superior colliculus after 1 to 3 weeks of survival. The content of adenosine receptors also varies in the contralateral target after ME. A transient increase in A1 receptors is observed in the early periods of plasticity, while A2a receptors are upregulated later. Interestingly, the local blockade of A2a receptors abolished the increase in GFAP and the retinotectal reorganization induced by monocular enucleation during the critical period. Taken together these results suggest a correlation between astrocytes and A2a adenosine receptors in the subcortical visual plasticity.
Assuntos
Astrócitos , Colículos Superiores , Animais , Ratos , Astrócitos/metabolismo , Enucleação Ocular , Colículos Superiores/metabolismo , Receptores Purinérgicos P1/metabolismo , Imuno-Histoquímica , Receptor A2A de Adenosina/metabolismoRESUMO
Benzodiazepines, such as diazepam (DZP), are used to treat anxiety disorders, and are prescribed to pregnant woman for therapeutic purposes. Concerns regarding their consequences on postnatal development rise as they cross the placenta and interact with the embryo. Occurrence of malformation and behavioral syndromes have been reported for different ages, but little is known about their effects on the brain after exposure during intrauterine life. Thus, we sought to evaluate the effects of intrauterine exposure to DZP on the number of brainstem's catecholaminergic and serotonergic neurons, implicated in respiratory control, in male and female rats on postnatal (P) day 12-13, using immunofluorescence labeling for tyrosine-hydroxylase (TH) and serotonin (5-HT). We observed a reduction in the number of catecholaminergic neurons for males and females. Special attention is given to the reduction in the density of neurons in the A6 region, involved in ventilatory responses to CO2. Interestingly, only males showed a reduction in the number of serotonergic neurons, while females were not affected. These findings suggest that in utero exposure to DZP results in deleterious neuroanatomical effects on P12-13 rats and raises a note of concern for women clinicians to make more informed choices about the use of anxiolytic treatments during gestation.
Assuntos
Ansiolíticos , Diazepam , Gravidez , Ratos , Animais , Feminino , Masculino , Diazepam/farmacologia , Neurônios Serotoninérgicos , Benzodiazepinas/farmacologia , Ansiolíticos/farmacologia , Encéfalo , Serotonina/farmacologiaRESUMO
The plasticity of the central nervous system (CNS) allows the change of neuronal organization and function after environmental stimuli or adaptation after sensory deprivation. The so-called critical period (CP) for neuroplasticity is the time window when each sensory brain region is more sensitive to changes and adaptations. This time window is usually different for each primary sensory area: somatosensory (S1), visual (V1), and auditory (A1). Several intrinsic mechanisms are also involved in the start and end of the CP for neuroplasticity; however, which is its duration in S1, VI, and A1? This systematic review evaluated studies on the determination of these time windows in small rodents. The careful study selection and methodological quality assessment indicated that the CP for neuroplasticity is different among the sensory areas, and the brain maps are influenced by environmental stimuli. Moreover, there is an overlap between the time windows of some sensory areas. Finally, the time window duration of the CP for neuroplasticity is predominant in S1.
RESUMO
Aim: To analyze the effects of exposure to a high-fat diet during the perinatal period and after weaning on white adipose tissue accumulation and gene expression of TNF- α and NF- κB.Method: Wistar female rats were fed with high-fat (H) or control (C) diet during pregnancy and lactation. The offspring were allocated into four groups: Control Control (CC), offspring of mothers GC, fed a control diet after weaning; Control High-fat (CH), offspring of mothers GC, fed a hight-fat diet after weaning; High-fat Control (HC), offspring of mothers GH, fed with control diet after weaning; and High-fat High-fat (HH), offspring of mothers GH, fed a H diet after weaning.Results: HH and HC groups showed increased body weight compared to CC group and increases in caloric intake, larger amount of white adipose tissue and adipocyte size compared to CC and CH groups. The HH and CH groups showed higher NF-kB expression in white adipose tissue compared to the CC and HC groups, and the HH group also showed higher TNF- α expression. In the hypothalamus, the HH and HC groups exhibited higher TNF- α expression compared to the CC and CH groups.Conclusion: Perinatal and post-weaning exposure to the high-fat diet increases the amount of white adipose tissue, adipocyte size, and expression of the inflammatory genes TNF-α and NF-kB.
Assuntos
NF-kappa B , Fator de Necrose Tumoral alfa , Tecido Adiposo/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Peso Corporal , Dieta Hiperlipídica/efeitos adversos , Feminino , Hipotálamo/metabolismo , Lactação , NF-kappa B/genética , NF-kappa B/metabolismo , Gravidez , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , DesmameRESUMO
Exposure to the hight-fat diet may alter the control of food intake promoting hyperphagia and obesity. The objective of this study was to investigate the effects of this diet on dopamine receptors (drd1 and drd2), proopiomelanocortin (pomc), neuropeptideY (npy) genes expression, and preference food in adult rats. Wistar female rats were fed a hight-fat or control diet during pregnancy and lactation. The offspring were allocated into groups: Lactation - Control (C) and High-fat (H). Post-weaning Control Control (CC), offspring of mothers C, fed a control diet after weaning; Control Hight-fat (CH), offspring of mothers C, fed a hight-fat diet after weaning; Hight-fat Control (HC), offspring of mothers H, fed with control diet after weaning; and Hight-fat Hight-fat (HH), offspring of mothers H, fed a H diet after weaning. The groups CH and HH presented greater expression of drd1 in comparison to the CC. The drd2 of CH and HC presented higher gene expression than did CC. HH presented higher pomc expression in comparison to the other groups. HC also presented greater expression in comparison to CH. The npy of HH presented greater expression in relation to CH and HC. HH and HC have had a higher preference for a high-fat diet at 102º life's day. The high-fat diet altered the gene expression of the drd1, drd2, pomc and npy, and influencing the food preference for high-fat diet.
A exposição à dieta hiperlipídica pode alterar o controle da ingestão de alimentos, promovendo hiperfagia e obesidade. O objetivo deste estudo foi investigar os efeitos dessa dieta sobre a expressão gênica dos receptores de dopamina (drd1 e drd2), da proopiomelanocortina (pomc) e neuropeptídeo Y (npy), e preferência alimentar em ratos adultos. Ratas Wistar foram alimentadas com uma dieta hiperlipídica ou controle durante a gestação e lactação. Os descendentes foram alocados em grupos: Lactação Controle (C) e Hiperlipídica (H). Pós-desmame - Controle Controle (CC), descendentes das genitoras do grupo controle e alimentados com dieta controle após o desmame; Controle Hiperlipídica (CH), descendentes das genitoras do grupo controle e alimentados com dieta hiperlipídica após o desmame; Hiperlipídica Controle (HC), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta controle após o desmame; Hiperlipídica Hiperlipídica (HH), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta hiperlipídica após o desmame. Os grupos CH e HH apresentaram maior expressão de drd1 em comparação ao CC. O drd2 de CH e HC apresentou maior expressão gênica que o CC. HH apresentou maior expressão de pomc em comparação com os outros grupos. O HC também apresentou maior expressão de pomc em comparação ao CH. O npy do HH apresentou maior expressão em relação ao CH e HC. HH e HC tiveram uma preferência maior por uma dieta rica em gordura no 102º dia de vida. A dieta hiperlipídica alterou a expressão gênica dos drd1, drd2, pomc e npy e influenciou na preferência alimentar pela dieta hiperlipídica.
Assuntos
Animais , Feminino , Gravidez , Ratos , Pró-Opiomelanocortina/genética , Dieta Hiperlipídica/efeitos adversos , Peso Corporal , Neuropeptídeo Y/genética , Expressão Gênica , Receptores Dopaminérgicos/genética , Ratos Wistar , Preferências AlimentaresRESUMO
Exposure to the hight-fat diet may alter the control of food intake promoting hyperphagia and obesity. The objective of this study was to investigate the effects of this diet on dopamine receptors (drd1 and drd2), proopiomelanocortin (pomc), neuropeptideY (npy) genes expression, and preference food in adult rats. Wistar female rats were fed a hight-fat or control diet during pregnancy and lactation. The offspring were allocated into groups: Lactation Control (C) and High-fat (H). Post- weaning Control Control (CC), offspring of mothers C, fed a control diet after weaning; Control Hight-fat (CH), offspring of mothers C, fed a hight-fat diet after weaning; Hight-fat Control (HC), offspring of mothers H, fed with control diet after weaning; and Hight-fat Hight-fat (HH), offspring of mothers H, fed a H diet after weaning. The groups CH and HH presented greater expression of drd1 in comparison to the CC. The drd2 of CH and HC presented higher gene expression than did CC. HH presented higher pomc expression in comparison to the other groups. HC also presented greater expression in comparison to CH. The npy of HH presented greater expression in relation to CH and HC. HH and HC have had a higher preference for a high-fat diet at 102º lifes day. The high-fat diet altered the gene expression of the drd1, drd2, pomc and npy, and influencing the food preference for high-fat diet.
A exposição à dieta hiperlipídica pode alterar o controle da ingestão de alimentos, promovendo hiperfagia e obesidade. O objetivo deste estudo foi investigar os efeitos dessa dieta sobre a expressão gênica dos receptores de dopamina (drd1 e drd2), da proopiomelanocortina (pomc) e neuropeptídeo Y (npy), e preferência alimentar em ratos adultos. Ratas Wistar foram alimentadas com uma dieta hiperlipídica ou controle durante a gestação e lactação. Os descendentes foram alocados em grupos: Lactação Controle (C) e Hiperlipídica (H). Pós-desmame Controle Controle (CC), descendentes das genitoras do grupo controle e alimentados com dieta controle após o desmame; Controle Hiperlipídica (CH), descendentes das genitoras do grupo controle e alimentados com dieta hiperlipídica após o desmame; Hiperlipídica Controle (HC), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta controle após o desmame; Hiperlipídica Hiperlipídica (HH), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta hiperlipídica após o desmame. Os grupos CH e HH apresentaram maior expressão de drd1 em comparação ao CC. O drd2 de CH e HC apresentou maior expressão gênica que o CC. HH apresentou maior expressão de pomc em comparação com os outros grupos. O HC também apresentou maior expressão de pomc em comparação ao CH. O npy do HH apresentou maior expressão em relação ao CH e HC. HH e HC tiveram uma preferência maior por uma dieta rica em gordura no 102º dia de vida. A dieta hiperlipídica alterou a expressão gênica dos drd1, drd2, pomc e npy e influenciou na preferência alimentar pela dieta hiperlipídica.
Assuntos
Feminino , Animais , Ratos , Dieta Hiperlipídica/efeitos adversos , Dieta Hiperlipídica/veterinária , Dopamina/análise , Neuropeptídeo Y/análise , Pró-Opiomelanocortina/análise , Ratos WistarRESUMO
Abstract Exposure to the hight-fat diet may alter the control of food intake promoting hyperphagia and obesity. The objective of this study was to investigate the effects of this diet on dopamine receptors (drd1 and drd2), proopiomelanocortin (pomc), neuropeptideY (npy) genes expression, and preference food in adult rats. Wistar female rats were fed a hight-fat or control diet during pregnancy and lactation. The offspring were allocated into groups: Lactation Control (C) and High-fat (H). Post-weaning Control Control (CC), offspring of mothers C, fed a control diet after weaning; Control Hight-fat (CH), offspring of mothers C, fed a hight-fat diet after weaning; Hight-fat Control (HC), offspring of mothers H, fed with control diet after weaning; and Hight-fat Hight-fat (HH), offspring of mothers H, fed a H diet after weaning. The groups CH and HH presented greater expression of drd1 in comparison to the CC. The drd2 of CH and HC presented higher gene expression than did CC. HH presented higher pomc expression in comparison to the other groups. HC also presented greater expression in comparison to CH. The npy of HH presented greater expression in relation to CH and HC. HH and HC have had a higher preference for a high-fat diet at 102º lifes day. The high-fat diet altered the gene expression of the drd1, drd2, pomc and npy, and influencing the food preference for high-fat diet.
Resumo A exposição à dieta hiperlipídica pode alterar o controle da ingestão de alimentos, promovendo hiperfagia e obesidade. O objetivo deste estudo foi investigar os efeitos dessa dieta sobre a expressão gênica dos receptores de dopamina (drd1 e drd2), da proopiomelanocortina (pomc) e neuropeptídeo Y (npy), e preferência alimentar em ratos adultos. Ratas Wistar foram alimentadas com uma dieta hiperlipídica ou controle durante a gestação e lactação. Os descendentes foram alocados em grupos: Lactação Controle (C) e Hiperlipídica (H). Pós-desmame Controle Controle (CC), descendentes das genitoras do grupo controle e alimentados com dieta controle após o desmame; Controle Hiperlipídica (CH), descendentes das genitoras do grupo controle e alimentados com dieta hiperlipídica após o desmame; Hiperlipídica Controle (HC), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta controle após o desmame; Hiperlipídica Hiperlipídica (HH), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta hiperlipídica após o desmame. Os grupos CH e HH apresentaram maior expressão de drd1 em comparação ao CC. O drd2 de CH e HC apresentou maior expressão gênica que o CC. HH apresentou maior expressão de pomc em comparação com os outros grupos. O HC também apresentou maior expressão de pomc em comparação ao CH. O npy do HH apresentou maior expressão em relação ao CH e HC. HH e HC tiveram uma preferência maior por uma dieta rica em gordura no 102º dia de vida. A dieta hiperlipídica alterou a expressão gênica dos drd1, drd2, pomc e npy e influenciou na preferência alimentar pela dieta hiperlipídica.
RESUMO
Exposure to the hight-fat diet may alter the control of food intake promoting hyperphagia and obesity. The objective of this study was to investigate the effects of this diet on dopamine receptors (drd1 and drd2), proopiomelanocortin (pomc), neuropeptideY (npy) genes expression, and preference food in adult rats. Wistar female rats were fed a hight-fat or control diet during pregnancy and lactation. The offspring were allocated into groups: Lactation Control (C) and High-fat (H). Post- weaning Control Control (CC), offspring of mothers C, fed a control diet after weaning; Control Hight-fat (CH), offspring of mothers C, fed a hight-fat diet after weaning; Hight-fat Control (HC), offspring of mothers H, fed with control diet after weaning; and Hight-fat Hight-fat (HH), offspring of mothers H, fed a H diet after weaning. The groups CH and HH presented greater expression of drd1 in comparison to the CC. The drd2 of CH and HC presented higher gene expression than did CC. HH presented higher pomc expression in comparison to the other groups. HC also presented greater expression in comparison to CH. The npy of HH presented greater expression in relation to CH and HC. HH and HC have had a higher preference for a high-fat diet at 102º lifes day. The high-fat diet altered the gene expression of the drd1, drd2, pomc and npy, and influencing the food preference for high-fat diet.(AU)
A exposição à dieta hiperlipídica pode alterar o controle da ingestão de alimentos, promovendo hiperfagia e obesidade. O objetivo deste estudo foi investigar os efeitos dessa dieta sobre a expressão gênica dos receptores de dopamina (drd1 e drd2), da proopiomelanocortina (pomc) e neuropeptídeo Y (npy), e preferência alimentar em ratos adultos. Ratas Wistar foram alimentadas com uma dieta hiperlipídica ou controle durante a gestação e lactação. Os descendentes foram alocados em grupos: Lactação Controle (C) e Hiperlipídica (H). Pós-desmame Controle Controle (CC), descendentes das genitoras do grupo controle e alimentados com dieta controle após o desmame; Controle Hiperlipídica (CH), descendentes das genitoras do grupo controle e alimentados com dieta hiperlipídica após o desmame; Hiperlipídica Controle (HC), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta controle após o desmame; Hiperlipídica Hiperlipídica (HH), descendentes das genitoras do grupo hiperlipídica e alimentados com dieta hiperlipídica após o desmame. Os grupos CH e HH apresentaram maior expressão de drd1 em comparação ao CC. O drd2 de CH e HC apresentou maior expressão gênica que o CC. HH apresentou maior expressão de pomc em comparação com os outros grupos. O HC também apresentou maior expressão de pomc em comparação ao CH. O npy do HH apresentou maior expressão em relação ao CH e HC. HH e HC tiveram uma preferência maior por uma dieta rica em gordura no 102º dia de vida. A dieta hiperlipídica alterou a expressão gênica dos drd1, drd2, pomc e npy e influenciou na preferência alimentar pela dieta hiperlipídica.(AU)
Assuntos
Animais , Feminino , Ratos , Dieta Hiperlipídica/efeitos adversos , Dieta Hiperlipídica/veterinária , Dopamina/análise , Pró-Opiomelanocortina/análise , Neuropeptídeo Y/análise , Ratos WistarRESUMO
Este artigo pretende estabelecer uma conexão entre a neurociência e o ensino e aprendizagem de uma língua estrangeira; começando por uma introdução do assunto; em seguida apresentando uma visão geral de quais áreas do cérebro estão relacionadas à linguagem, as conceituações da neuroplasticidade e os diferentes conceitos da hipótese do período crítico e sensível. Após, é realizada uma análise de quais contribuições a neurociência fez no campo de ensino e aprendizagem de línguas, bem como de que modo essas contribuições podem ser adaptadas e aplicadas em uma sala de aula de língua estrangeira. Concluiu-se que a neurociência pode ser capaz de apoiar as metodologias do professor, a fim de melhorar suas técnicas e facilitar o aprendizado dos alunos.
This paper intends to establish a connection between neuroscience and the teaching and learning of a foreign language. It starts with an introduction of the subject, proceeding to an overview of the brain areas related to language, the conceptualizations of neuroplasticity and the different concepts of the critical period and sensitive period hypothesis. Then, the contributions of neuroscience has made in the language teaching and learning field will be analyzed, as well as how these contributions can be adapted and applied to a foreign language classroom. It was concluded that neuroscience might be able to support the teacher's methodologies in order to improve his/her techniques and facilitate students' learning.
Assuntos
Humanos , Metodologia como Assunto , Neurociência Cognitiva , Idioma , Aprendizagem , EnsinoRESUMO
Recent studies have shown that exposure to fluoxetine treatment induces excessive production of ROS, and alters the antioxidant defense system in various tissues and cell types, mainly the liver. When fluoxetine is administered intraperitoneally, the drug rapidly reaches high concentrations in the liver, has potentially multiple toxic effects on energy metabolism in rat liver mitochondria. The aim of this study was to evaluate the effect of pharmacological treatment with fluoxetine during critical period for development on the mitochondrial bioenergetics and oxidative stress in liver of rat adult. To perform this study, the rat pups received Fx, or vehicle (Ct) from postnatal day 1 to postnatal day 21 (ie, during lactation period). We evaluated mitochondrial oxygen consumption, respiratory control ratio, ROS production, mitochondrial swelling by pore opening, oxidative stress biomarkers, and antioxidant defense in liver of rats at 60 days of age. Our studies have shown, that treatment with Fx during the lactation period resulted in reduced body mass gain, improvement of the mitochondrial respiratory capacity, induced higher mitochondrial resistance to calcium ion preventing the mitochondrial permeability transition pore opening, as well as decreased oxidative stress biomarkers, and increased the SH levels and enzymes antioxidant activities (SOD, CAT, GST) in liver of treated rats at 60 days of age. These findings suggest that pharmacological treatment with fluoxetine during critical period of development result in positive changes in liver of rats, as improvement of the mitochondrial bioenergetics and hepatic oxidative metabolism that persist in adulthood.
Assuntos
Fluoxetina/farmacologia , Fígado/metabolismo , Mitocôndrias Hepáticas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Animais , Cálcio/metabolismo , Ratos , Ratos WistarRESUMO
Two experiments were conducted with the aim of determining the effect of equine chorionic gonadotropin (eCG) administration on day 14 after insemination on ovarian response and pregnancy establishment in postpartum anestrous beef cows. In both experiments, cows were subjected to a progesterone- and estradiol-based treatment for fixed-time artificial insemination (FTAI) and were randomly allocated into 4 groups to receive or not receive eCG (400 IU) at the time of device removal and/or at 14 d after FTAI. In experiment 1, from day 14 to 22, daily ultrasonographic determinations were performed to monitor ovarian dynamics, and blood was collected to determine hormone concentrations in 60 cows. In experiment 2, confirmation of pregnancy was performed at 30 and 60 d after FTAI in 1,060 anestrous cows assigned to the same experimental design. Cows that received eCG on day 14 after FTAI showed increases in corpus luteum area (P < 0.01), follicle diameter (P < 0.05), serum progesterone concentrations (P < 0.01), and estradiol-17ß concentrations (P < 0.01), compared with cows that did not receive eCG on day 14. Pregnancy rate on day 30 was greater in those cows that received both eCG treatments (ie, at device removal and 14 d after insemination) than in those that did not receive eCG treatment (P < 0.05). In conclusion, eCG administered on day 14 after FTAI increases serum progesterone concentrations during the critical period of pregnancy in anestrous cows, and this second eCG treatment seems to have a positive effect on achieving pregnancy.
Assuntos
Bovinos/fisiologia , Corpo Lúteo/efeitos dos fármacos , Gonadotropinas Equinas/farmacologia , Prenhez , Animais , Corpo Lúteo/fisiologia , Sincronização do Estro/fisiologia , Feminino , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial/veterinária , Período Pós-Parto , Gravidez , Prenhez/efeitos dos fármacosRESUMO
The sweep visual evoked potential method (sVEP) is a powerful tool for measurement of visual acuity in infants. Despite the applicability and reliability of the technique in measuring visual functions the understanding of sVEP acuity maturation and how interocular difference of acuity develops in early infancy, as well as the availability of normality ranges, are rare in the literature. We measured binocular and monocular sVEPS acuities in 481 healthy infants aged from birth to 24 months without ophthalmological diseases. Binocular sVEP acuity was significantly higher than monocular visual acuities for almost all ages. Maturation of monocular sVEP acuity showed 2 longer critical periods while binocular acuity showed three maturation periods in the same age range. We found a systematic variation of the mean interocular acuity difference (IAD) range according to age from 1.45 cpd at birth to 0.31 cpd at 24 months. An additional contribution was the determination of sVEP acuity norms for the entire age range. We conclude that binocular and monocular sVEP acuities have distinct growth curves reflecting different maturation profiles for each function. Differences in IAD range shorten according to age and they should be considered in using the sVEP acuity measurements for clinical diagnosis as amblyopia.
Assuntos
Potenciais Evocados Visuais/fisiologia , Valores de Referência , Acuidade Visual/fisiologia , Córtex Visual/crescimento & desenvolvimento , Fatores Etários , Pré-Escolar , Eletroencefalografia/métodos , Feminino , Humanos , Lactente , Masculino , Reprodutibilidade dos Testes , Fatores Sexuais , Fatores de TempoRESUMO
Critical periods of plasticity (CPPs) are defined by developmental intervals wherein neuronal circuits are most susceptible to environmental influences. The CPP of the prefrontal cortex (PFC), which controls executive functions, extends up to early adulthood and, like other cortical areas, reflects the maturation of perineuronal nets (PNNs) surrounding the cell bodies of specialized inhibitory interneurons. The aim of the present work was to evaluate the effect of chronic stress on both structure and function of the adolescent's rat PFC. We subjected P28 rats to stressful situations for 7, 15 and 35days and evaluated the spatial distribution of histochemically-labeled PNNs in both the Medial Prefrontal Cortex (MPFC) and the Orbitofrontal Cortex (OFC) and PFC-associated behavior as well. Chronic stress affects PFC development, slowing PNN maturation in both the (MPFC) and (OFC) while negatively affecting functions associated with these areas. We speculate upon the risks of prolonged exposure to stressful environments in human adolescents and the possibility of stunted development of executive functions.
Assuntos
Comportamento Animal/fisiologia , Matriz Extracelular/fisiologia , Interneurônios/fisiologia , Córtex Pré-Frontal/crescimento & desenvolvimento , Estresse Psicológico/fisiopatologia , Fatores Etários , Animais , Masculino , Ratos , Ratos Wistar , Comportamento Espacial/fisiologiaRESUMO
Retinocollicular connections form precise topographical maps that are normally completed through the selective elimination of misplaced axons and the stabilization of topographically ordered axon terminals during early development. Omega-3 fatty acids, acquired exclusively through the diet, and its main metabolite, docosahexaenoic acid (DHA), are involved in brain development and synaptic maturation. We have previously shown that the nutritional restriction of omega-3/DHA results in abnormal retinocollicular topographical fine-tuning. Therefore, we studied the role of omega-3 fatty acids nutritional supplementation and the developmental time windows during which this postnatal supplementation would restore normal topographical maps in the visual system. Female rats and their litters were chronically fed with either control (soy oil) or restricted omega-3 (coconut oil) diets. Fish oil supplementation was introduced between either postnatal day (PND) 7-13, PND7-28 or PND21-42. At PND13, PND28 or PND42, animals received an anterograde eye injection of a neuronal tracer to visualize retinocollicular axons. Confirming previous observations we found that an omega-3/DHA deficiency resulted in an abnormally high innervation density of retinal axons at the visual layers of the superior colliculus (SC). Although a short-term fish oil supplementation between PND7-13 could not restore normal retinocollicular topography, an extended treatment between PND7-28 completely recovered normal innervation densities of retinotectal axons. However, a late onset supplementation protocol, between PND28-42, was no longer effective in the restoration of the abnormal topographical pattern induced by an early omega-3 nutritional malnutrition. The results suggest a critical period for omega3/DHA dietary intake for the proper development of visual topographical maps.
Assuntos
Ácidos Graxos Ômega-3/administração & dosagem , Retina/crescimento & desenvolvimento , Colículos Superiores/crescimento & desenvolvimento , Vias Visuais/crescimento & desenvolvimento , Animais , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Feminino , Ratos , Retina/citologia , Colículos Superiores/citologia , Fatores de TempoRESUMO
Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching) larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata) and rotifers (Brachionus plicatilis) were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.(AU)
Con el objeto de determinar si las técnicas morfométricas e histológicas permiten diferenciar larvas en estado de inanición de las sometidas a tratamientos de alimentación, ejemplares de Pagrus pagrus fueron criados en laboratorio bajo condiciones controladas. Una vez que el vitelo fue consumido (tres días luego de la eclosión) las larvas fueron sometidas a diferentes tratamientos de alimentación: completamente privadas de alimento, privadas de alimento durante tres días y luego alimentadas, y alimentadas durante todo el experimento. Algas (Nannochloropsis oculata) y rotíferos (Brachionus plicatilis) fueron proporcionados a las larvas de los tratamientos de alimentación. Diariamente se fijaron ejemplares de los tres tratamientos en formol 5% para estudios morfométricos y en Bouin para estudios histológicos. Los resultados obtenidos dan evidencias de que las metodologías presentadas son suficientemente sensibles para determinar diferencias en la condición de larvas sometidas a los tratamientos de alimentación. Por lo tanto, podrían ser empleadas para determinar la condición nutricional de las larvas de besugo recolectadas en el mar. Por otra parte, éstas metodologías podrían ser empleadas para determinar la calidad de larvas producidas en acuicultura y evaluar los efectos de modificaciones introducidas en los protocolos de crianza o en el tipo de alimento suministrado con el objeto de mejorar la supervivencia de los estadios tempranos de desarrollo.(AU)
Assuntos
Animais , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Peixes/classificação , Larva , Inanição , Perciformes/classificaçãoRESUMO
Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching) larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata) and rotifers (Brachionus plicatilis) were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.
Con el objeto de determinar si las técnicas morfométricas e histológicas permiten diferenciar larvas en estado de inanición de las sometidas a tratamientos de alimentación, ejemplares de Pagrus pagrus fueron criados en laboratorio bajo condiciones controladas. Una vez que el vitelo fue consumido (tres días luego de la eclosión) las larvas fueron sometidas a diferentes tratamientos de alimentación: completamente privadas de alimento, privadas de alimento durante tres días y luego alimentadas, y alimentadas durante todo el experimento. Algas (Nannochloropsis oculata) y rotíferos (Brachionus plicatilis) fueron proporcionados a las larvas de los tratamientos de alimentación. Diariamente se fijaron ejemplares de los tres tratamientos en formol 5% para estudios morfométricos y en Bouin para estudios histológicos. Los resultados obtenidos dan evidencias de que las metodologías presentadas son suficientemente sensibles para determinar diferencias en la condición de larvas sometidas a los tratamientos de alimentación. Por lo tanto, podrían ser empleadas para determinar la condición nutricional de las larvas de besugo recolectadas en el mar. Por otra parte, éstas metodologías podrían ser empleadas para determinar la calidad de larvas producidas en acuicultura y evaluar los efectos de modificaciones introducidas en los protocolos de crianza o en el tipo de alimento suministrado con el objeto de mejorar la supervivencia de los estadios tempranos de desarrollo.
Assuntos
Animais , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Larva , Peixes/classificação , Perciformes/classificação , InaniçãoRESUMO
Objective. To represent how a new identity is being constructed by nurses initiating their activities as teachers. Methodology. In 2010, a descriptive-interpretative qualitative research was conducted of four cases of nurse teachers from Nursing Schools. Aspects of teacher identity and management of critical incidents in the classroom were reviewed. The information was obtained through a structured survey and the data underwent analysis of contents. Results. The nurses surveyed state that the teaching exercise is a culmination stage of clinical nursing. Teaching confers them stability in their professional life; however, they report that the complexity of the educational practice poses a big challenge. They feel responsible for the formation of future nursing professionals. In spite of defining themselves as constructivists in the way of teaching, they are governed by a technical conception on the way of approaching the educational practice. They attribute the critical incidents to which they are exposed to the types of students entering the universities; these turn out uncomfortable and do not feel responsible for their development. These incidents are lessons to better face similar situations in the future. Conclusion. The nurses participating in this study are facing their new role as teachers of human resource, seeking to construct a new identity different from what they had when working in direct care of individuals.
Objetivo. Representar cómo se construye una nueva identidad la enfermera que inicia su actividad como formadora. Metodología. En 2010 se realizó una investigación cualitativa de corte descriptivo-interpretativo de cuatro casos de enfermeras profesoras de Escuelas de Enfermería. Se revisaron aspectos de la identidad docente y del manejo de incidentes críticos en el aula. La información fue obtenida mediante entrevista estructurada y a los datos se les hizo análisis de contenido. Resultados. Las enfermeras entrevistadas afirman que el ejercicio docente es una etapa de culminación de la enfermería clínica. La labor de la docencia les confiere estabilidad en su vida profesional, sin embargo aseguran que la complejidad de la práctica educativa les plantea un gran desafío puesto que se sienten responsables de la formación de los futuros enfermeros. A pesar de definirse como constructivistas en la manera de enseñar, se rigen por una concepción técnica en la forma de abordar la práctica educativa. Los incidentes críticos a los que se exponen los atribuyen al tipo de estudiante que ingresa, les resultan incómodos y no se sienten responsables del desarrollo de los mismos. Estos incidentes son un aprendizaje que les permitirá enfrentarse mucho mejor a situaciones similares en el futuro. Conclusión. Las enfermeras participantes en este estudio enfrentan un nuevo rol como formadoras de recurso humano, para lo cual intentan construir una identidad nueva diferente a la que tenían cuando trabajaban en el cuidado directo de las personas.
Objetivo. Representar como está construindo uma nova identidade a enfermeira que inicia sua atividade como formadora. Metodologia. Em 2010 se realizou uma investigação qualitativa de corte descritivo-interpretativo de quatro casos de enfermeiras professoras de Escolas de Enfermaria. Revisaram-se aspectos da identidade docente e do manejo de incidentes críticos no sala de aula. A informação foi obtida mediante entrevista estruturada e aos dados se lhes fez análises de conteúdo. Resultados. As enfermeiras entrevistadas afirmam que o exercício docente é uma etapa de culminação da enfermaria clínica. O labor da docência lhes confere estabilidade em sua vida profissional, no entanto asseguram que a complexidade da prática educativa lhes propõe um grande desafio. Sentem-se responsáveis da formação dos futuros enfermeiros. Apesar de definir-se como construtivistas na maneira de ensinar, regem-se por uma concepção técnica na forma de abordar a prática educativa. Os incidentes críticos aos que se veem expostas os atribuem ao tipo de estudante que ingressa nas universidades, resultam-lhes incômodos e não se sentem responsáveis do desenvolvimento dos mesmos. Estes incidentes são uma aprendizagem para enfrentar-se melhor a situações similares no futuro. Conclusão. As enfermeiras participantes neste estudo estão enfrentando seu novo papel como formadoras de recurso humano, tentando construir uma identidade nova diferente à que tinham quando trabalhavam em cuidado direto às pessoas.
Assuntos
Humanos , Docentes de Enfermagem , Educação em Enfermagem , Papel do Profissional de EnfermagemRESUMO
The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived on postnatal day 10 and divided into two groups at weaning: standard environment (SE group, n = 4) and enriched environment (EE group, n = 4). After 3 months, all of the mice were subjected to grating visual acuity tests, sacrificed, and perfused with aldehyde fixative. The brains were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95 percent confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.
Assuntos
Animais , Camundongos , Meio Ambiente , Visão Monocular , Acuidade Visual , Córtex VisualRESUMO
The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived on postnatal day 10 and divided into two groups at weaning: standard environment (SE group, n = 4) and enriched environment (EE group, n = 4). After 3 months, all of the mice were subjected to grating visual acuity tests, sacrificed, and perfused with aldehyde fixative. The brains were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95 percent confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.(AU)
Assuntos
Animais , Camundongos , Visão Monocular , Meio Ambiente , Acuidade Visual , Córtex Visual , Rede NervosaRESUMO
Desde la etapa prenatal, la organización neuro-fisiológica del bebé lo prepara para realizar con efectividad los procesos vitales de succión, deglución y respiración. Los reflejos y experiencias intrauterinas le permitirán poder alimentarse inmediatamente al nacer. Se estima que cerca del término de la gestación, el feto humano deglute entre 500-1000cc de líquido amniótico cada día. El pico de sinaptogénesis sucede entre 34 y 36 semanas de edad gestacional, que es el tiempo donde la succión nutritiva es segura. El ritmo de la succión se establece a las 32 semanas. El proceso de alimentarse sufre encefalización cuando los reflejos son integrados, entonces pasa de un ritmo de alimentación reflejo, a tener la capacidad de alterar voluntaria y cualitativamente la estrategia de alimentación. Este proceso se consolida debido a la integración sensoriomotora de la deglución con la respiración, la coordinación ojo-mano, el tono muscular normal, la postura y un apropiado ambiente psicosocial. Alimentarse, especialmente en los primeros años de vida, es un proceso mutuo, se necesitan dos personas para lograrlo, y por eso, si alguna de las dos carece de las habilidades necesarias, esto puede generar problemas de la alimentación. Nada sustituye la valoración realizada con una historia clínica y un examen físico dirigidos a valorar cuán efectiva es la fase oral y faríngea mientras el bebé es alimentado. Cuando se presenten dificultades, la intervención debe ser activa, eso incluye la toma de decisiones médicas y quirúrgicas, protección de la vía aérea, suministro del aporte calórico idóneo para las necesidades del infante. Se deben además brindar estrategias maduracionales para su nivel de desarrollo alimentario actual y para ir adquiriendo las habilidades esperadas en elfuturo cercano y tardío