Effects of early-life stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats.

Early-life stress and subsequent high-calorie diets during adolescence are known to be risk factors for developing metabolic and psychological disorders. Although non-nutritive sweeteners such as stevia and sucralose have been a useful alternative to reduce sugar consumption, the effects of prolonged consumption of these sweeteners on metabolism and behavior in adolescents remain unclear. Here, we evaluated the effects of early-stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats. During postnatal days (PNDs) 1-21, pups were separated twice a day, for 180 min each time, from their dam nest while non-separated pups served as controls. The pups were weaned, separated by sex and randomly distributed into the stevia, sucralose and water conditions. During PNDs 26-50, two bottles containing water and stevia or sucralose were placed in the animal home-cages, and body weight and blood glucose measures were scored. On PNDs 50 and 51, behavioral measures were obtained in the open-field test. Results showed that male rats consuming stevia reduced body weight gain, blood glucose and increased locomotion. Early-stress led to low blood glucose and alterations in anxiety and locomotion-related behaviors in a sex-dependent manner. Moreover, sucralose access during adolescence reversed the effects of early-stress on anxiety-related behaviors in female rats. The results suggest that the consumption of stevia and sucralose could be an alternative for the replacement of sugar-sweetened beverages, especially in adolescents who have had adverse early-life experiences.

Expression of oxysterols in human lenses: Implications of the sterol pathway in age-related cataracts.

Lanosterol, an oxysterol molecule, has been proposed to help maintain lens transparency by inhibiting the formation of protein aggregates. This sterol is produced by the enzyme lanosterol synthase and is part of a metabolic pathway that forms cholesterol as a final step. Abnormalities in lanosterol synthase are responsible for congenital cataracts. The αA-crystallin protein, which acts as a molecular chaperone to lanosterol synthase, has been reported to have anti-protein aggregation, anti-inflammatory and anti-apoptotic properties. In this work, we evaluated the correlation of lanosterol synthase and αA-crystallin in human cataractous lenses with the grade of opacity, as well as the expression of lanosterol synthase, farnesyl DPP, geranyl synthase and squalene epoxidase genes. Lanosterol synthase and αA-crystallin were overexpressed in cataractous lenses as well as farnesyl-DP synthase, squalene epoxidase, lanosterol synthase and geranyl synthase genes in cataratous lenses in comparison with normal lenses. Our data confirm that lanosterol synthase and the sterol pathway are upregulated in cataractous lenses. This argues for a functional role of the oxysterol pathway and its products as an important mediator in the pathogenesis of human cataracts.

Efecto de la práctica repetida del estímulo táctil kinestésico en el peso del recién nacido prematuro / Effect of the repeated practice of the kinesthetic touch stimulus in the weight of the premature newborn

Objetivo: Determinar el efecto de la práctica repetida del estímulo táctil kinestésico (ETK) en la curva de peso del recién nacido prematuro (RNP). Metodología: El estudio tuvo un enfoque cuantitativo, de diseño cuasi experimental, realizado en una muestra de RNP (entre ≥29 y ≤35 semanas de gestación), hemodinámicamente estables, hospitalizados en la Unidad de Cuidado Neonatal del Hospital Simón Bolívar (Bogotá, Colombia). La muestra fue agrupada aleatoriamente; la enfermera practicó el ETK 3 veces al día (grupo experimental) y 1 vez al día (grupo control) durante 5 días consecutivos. La curva de peso y la relación peso/calorías (g.cal-1) se evaluaron mediante análisis de la varianza (ANOVA), ajuste de curva polinomial y test de la U de Mann-Whitney (p <0,05). Resultados: Se incluyeron en el estudio 38 RNP. Se calculó el peso en función del tiempo, y el porcentaje de aumento de peso frente a curvas de tiempo de ambos grupos no mostró diferencias estadísticas (p <0,05), con una varianza (F= 3,2208; p= 0,090) y un ajuste lineal similar (r2 = 0,99; p= 5,6.10–6), pero la razón peso/calorías muestra una diferencia significativa con los valores más altos para el grupo experimental (13,69 ± 0,2 g.cal–1) frente al grupo control (13,4 ± 0,09 g.cal–1; U de Mann-Whitney, p= 0,008). Conclusión: Estos resultados sugieren que la práctica repetida de ETK, durante al menos 5 días 3 veces al día, promueve el equilibrio anabólico, favoreciendo un mayor aumento de peso, evaluado por la proporción peso/calorías en los RNP. (AU)

Objective: To determine the effect of repeated practice of the (ETK) on the weight curve of the premature newborn. Methodology: Quantitative approach, quasi-experimental design, sample premature infants (between ≥29 and ≤35 weeks gestation), hemodynamically stable, hospitalized in the Neonatal Care Unit of Simón Bolívar Hospital (Bogotá, Colombia). Sample randomly grouped, the nurse practiced the ETK three times a day (experimental group) and once a day (control group) for five consecutive days. The weight curve and the weight/calorie ratio (g.cal–1) were evaluated by analysis of variance (ANOVA), polynomial curve fit and Mann-Whitney U-Test (p <0.05). Results: Sample 38 premature infants. Weight as a function of time and % of weight gain vs. time curves of both groups did not show statistical differences (p <0.05) with a variance (F= 3.2208; p= 0.090) and a similar linear adjustment (r2 = 0.99; p= 5.6.10–6), but the weight/calorie ratio shows a significant difference with the highest values for the experimental group (13.69 ± 0.2 g.cal–1) versus the control group (13.4 ± 0.09 g.cal–1; Mann-Whitney U-Test p= 0.008). Conclusion:These results suggest that repeated ETK practice, for at least 5 days three times a day, promotes anabolic balance favoring a greater weight gain, evaluated by the weight/calorie ratio in premature newborns. (AU)

Chronic stress caused by maternal separation is a possible risk factor for the development of 7,12-dimethyl benzo anthracene-induced breast tumors in rats.

BACKGROUND: Chronic stress has been investigated as a risk factor for breast cancer. Maternal separation (MS) of rats has been used as a chronic stress model that alters certain systemic functions, such as the immune response. OBJECTIVE: The aim of this study was to determine the possible effect of MS on the development of breast tumors induced by 7,12-dimethyl benzo anthracene (DMBA). METHODOLOGY: postnatal day (PND) 1 female Wistar rats were divided into four experimental groups that either were or were not subjected to MS and either received or did not receive DMBA. For MS, PND 1 to 21 pups were separated from their mothers for 360 min/day. On PND 30, carcinomas were induced in mammary glands using DMBA. Body weight was evaluated, and the injected region was palpated. In addition, the mammary glands were subjected to histological examination, and corticosterone levels were determined in all groups. RESULTS: DMBA-induced groups had significantly lower body weight gain compared with the non-DMBA-induced groups. Maternal separation increased the incidence of preneoplastic changes and breast carcinogenesis in DMBA-treated animals compared with control animals. Corticosterone levels were increased in both DMBA-induced and MS groups without interaction. CONCLUSION: MS is a possible risk factor for DMBA-induced preneoplastic changes and breast tumors in rats.

Salivary alpha amylase and cortisol levels as stress biomarkers in children with cerebral palsy and their association with a physical therapy program.

INTRODUCTION: Cerebral palsy (CP) is one of the main causes of physical disabilities in childhood. There is evidence that CP children display high levels of stress, which could interfere with learning processes and interpretation of relevant sensory information during motor skills acquisition and socialization. OBJECTIVE: This study aims to compare basal levels of stress biomarkers (cortisol and alpha-amylase) of healthy children (HC) and children with CP, and to investigate whether a physical therapy session using the neurodevelopmental technique (NDT) interferes with these levels. METHODS: A cross-sectional design was used. A total of 86 children (HC: n = 45 and CP: n = 41) with matching age, sex, socioeconomic status, and sampling time. Salivary cortisol and alpha-amylase levels were measured by means of electrochemiluminescence and spectrophotometry methods. A single saliva sample was collected in the HC group to determine basal levels. For CP group three samples were collected: a first sample was taken 20-30 min prior to the intervention, while two post-intervention samples were collected (5 and 20 min) to evaluate individual changes in salivary stress biomarkers. RESULTS: Higher basal cortisol concentration was found in CP children when compared to HC group. Moreover, CP children showed a significant reduction in cortisol levels 20 min after NDT intervention. No significant differences were observed in alpha-amylase values. CONCLUSION: Present results show that CP causes alteration in basal cortisol values at childhood and suggest that CP children respond to environmental regulatory factors such as NDT, in attempt to reduce stress.

Cellular count changes in different rat brain areas due to early maternal sepa ration / Cambios en el recuento celular en diferentes áreas del cerebro de rata debido a la separación materna temprana

Objective: to identify whether maternal separation during breastfeeding (MSDB) affects the cellular count in different rat brain areas. The continuous mother-child interaction,adjusts and modulates the offspring behavioral response to environmental stimuli and also affects their development and homeostasis. Morphological and physiological changes in the offspring brains have been observed, including cell count changes in different brain areas with differences between males and females. Materials and methods: this study compared albino Wistar rats in a protocol of MSDB with a control group. Brain tissue was fixed with paraformaldehyde, cut in cryostat and either stained with Hematoxylin-Eosin (H&E) or processed for immunohistochemistry against glial fibrillary acidic protein (GFAP). All sections were analyzed using a cell count protocol including statistical analysis with Students T test at a significance level of P ≤0.05.Results: the MSDB group of male subjects presented higher GFAP-marked cell count in primary motor cortex and hippocampus; while female subjects, showed less GFAPmarked cell count in these same areas. Conclusions: MSDB produces sex-specific changes in the number of glial cells especially in the primary motor cortex, this finding may be considered as associated factor of alterations in motor responses to stress in these subjects, in addition to other known causes such as the Hypothalamic-Pituitary- Adrenal Axis dysfunction..(AU)

Objetivo: identificar si la separación materna durante la lactancia (MSDB) afecta el conteo celular en cortezas motoras y otras áreas del cerebro de la rata. La interacción continua entre la madre y su hijo, ajusta y modula la respuesta comportamental de las crías hacia estímulos ambientales, afectando además su desarrollo y homeostasis. Cambios morfológicos y fisiológicos han sido descritos en la descendencia, incluyendo diferencias en conteos celulares de varias áreas de la corteza cerebral. Materiales y métodos: este estudio se compararon ratas Albino Wistar bajo un protocolo de MSDB contra un grupo control. El tejido cerebral fue fijado con paraformaldehido, cortado en criostato, y tratado con tinción Hematoxilina-Eosina (H&E) o procesado con inmunohistoquimica contra proteína acida glíal fibrilar (GFAP). Todas las secciones fueron analizadas usando un protocolo de conteo que incluyo análisis estadístico con el test de T de Student con significancia a nivel de P ≤0.05. Resultados: el grupo de machos que tuvo MSDB presentó mayor conteo de células marcadas contra GFAP en las cortezas motoras primarias y el hipocampo; mientras que las hembras con MSDB, mostraron menor conteo de células marcadas contra GFAP en estas mismas áreas. Conclusión: la MSDB produce cambios específicos de acuerdo al sexo del sujeto, en el número de células gliales especialmente en las cortezas motoras primarias, este hallazgo puede ser considerado como causante parcial de las alteraciones en las respuestas motoras a estrés en estos sujetos, además de otras causas conocidas como la disfunción del eje Hipotálamo-Pituitario-Adrenal (HPA)..(AU)

Hypochloremia in Patients with Severe Traumatic Brain Injury: A Possible Risk Factor for Increased Mortality.

OBJECTIVE: To determine association between electrolyte disturbances and mortality in patients with severe traumatic brain injury. METHODS: Medical records of patients with severe traumatic brain injury and Glasgow Coma Scale score <8 and electrolyte alterations were reviewed in a retrospective cohort study. Electrolyte levels were analyzed to establish an association between patients who died and patients who survived. Bivariate analysis was performed using χ2 test with a statistical reliability of 95% for categorical variables. Analysis for electrolyte changes to determine association with mortality was performed using χ2 test with multiple comparisons. Logistic regression was performed between the electrolyte alterations and their association with mortality. The reliability of statistical tests was 95%. RESULTS: There was a significant relationship between hypochloremia and increased risk of mortality in 23.1% of deceased patients (P = 0.03). Furthermore, there was a significant correlation with age (P < 0.01) and with the Acute Physiology and Chronic Health Evaluation APACHE II (P < 0.01). CONCLUSIONS: Hypochloremia could be an important prognostic factor to determine mortality risk and to improve treatment in patients with severe traumatic brain injury.

En ratas, el consumo de bebidas negras, normales o light, incrementa el peso corporal y la ansiedad / In rats, consumption of black drinks, normal or light, increases corporal weight and anxiety / Em ratos, o consumo de bebidas negras, normais ou light, incrementa o peso corporal e a ansiedade

Resumen El consumo de bebidas negras carbonatadas se asocia con obesidad debido a su alta concentración de azúcar. En efecto, la prevalencia de obesidad, sobre todo en niños, va en aumento, por lo que son pertinentes los estudios de factores de riesgo y los programas de prevención. En este sentido, el objetivo de este estudio piloto fue identificar, en un modelo animal, si el consumo de bebidas negras carbonatadas, normales y de dieta o light, afecta el peso y el comportamiento ansioso. Se seleccionaron 15 ratas Wistar macho, divididas en 3 grupos: un primer grupo de control, que bebía agua exclusivamente; un segundo grupo con suministro de agua y bebida negra carbonatada normal; un tercero con agua y bebida negra carbonatada light. Cada dos días se midió el consumo de bebida y alimento y cada semana se pesaron todos los sujetos. Pasadas cuatro semanas, se evaluaron comportamientos relacionados con ansiedad, utilizando el Laberinto en Cruz Elevado. Se encontraron diferencias significativas estadísticamente en el incremento del peso corporal de las ratas que consumieron bebidas negras normales y light, comparadas con el grupo que solo consumió agua. También se observó mayor consumo de las bebidas carbonatadas, si bien el consumo de alimento se mantuvo en proporciones muy similares para todos los grupos. Con respecto al tiempo de permanencia en los brazos cerrados, fue mayor en las ratas que consumieron bebida light comparadas con el grupo de control y, finalmente, ese mismo grupo mostró menor número de inmersiones de la cabeza en el laberinto. En conclusión, este estudio preliminar permite sugerir que el consumo de bebidas negras carbonatadas, normales y light, se asocia con un incremento del peso corporal de los animales y con mayor ansiedad.

Summary The consumption of carbonated black beverages is associated with obesity due to their high concentration of sugar. In effect, the prevalence of obesity, especially in children, is increasing; therefore, studies of risk factors and prevention programs are relevant. In this sense, the objective of this pilot study was to identify, in an animal model, whether the consumption of normal and diet or light black carbonated beverages affects weight and anxious behaviors. Fifteen male Wistar rats were selected and divided into 3 groups: a first control group, which drank water exclusively; a second group which drank both water and a normal black carbonated beverage; a third group which drank both water and a light black carbonated beverage. Every two days their food and beverage consumption was measured, and every week all the subjects were weighed. After four weeks, behaviors related to anxiety were evaluated using the Elevated Plus Maze. Statistically significant differences were found, including the increase in body weight of the rats that consumed normal and light black beverages compared with the group that only consumed water. There was also a higher consumption of carbonated beverages, although the consumption of food remained very similar for all groups. Regarding the time spent in the closed arms, it was greater for the rats that consumed light drinks compared with the control group; and finally, that same group showed a lower number of head dips (dipping) in the maze. In conclusion, this preliminary study suggests that the consumption of normal and light black carbonated beverages is associated with an increase in the body weight of animals and an increase in anxiety.

Resumo O consumo de bebidas negras gaseificadas se associa com obesidade devido a sua alta concentração de açúcar. Em efeito, a prevalência de obesidade, sobre tudo em crianças, vai em aumento, o que torna pertinentes os estudos de fatores de risco e os programas de prevenção. Neste sentido, o objetivo deste estudo piloto foi identificar, em um modelo animal, se o consumo de bebidas negras gaseificadas, normais e de dieta ou light, afeta o peso e o comportamento ansioso. Se selecionaram 15 ratos Wistar macho, divididos em 3 grupos: um primeiro grupo de controle, que bebia água exclusivamente; um segundo grupo com fornecimento de água e bebida negra gaseificada normal; um terceiro com água e bebida negra gaseificada light. A cada dois dias mediu-se o consumo de bebida e alimento e a cada semana se pesaram todos os sujeitos. Após quatro semanas, foram avaliados os comportamentos relacionados com ansiedade, utilizando o Labirinto em Cruz Elevado. Encontraram-se diferenças significativas estatisticamente no aumento do peso corporal dos ratos que consumiram bebidas negras normais e light, comparadas com o grupo que consumiu somente água. Também se observou um maior consumo das bebidas gaseificadas, embora o consumo de alimento tenha se mantido em proporções muito similares para todos os grupos. Com respeito ao tempo de permanência nos braços cerrados, foi superior nos ratos que consumiram bebida light comparadas com o grupo de controle e, finalmente, esse mesmo grupo mostrou um número inferior de imersões da cabeça não labirinto. Em conclusão, este estudo preliminar permite sugerir que o consumo de bebidas negras gaseificadas, normais e light, está associado com um aumento do peso corporal dos animais e com um maior nível de ansiedade.

Global Effects of Early Life Stress on Neurons and Glial Cells.

Early life stress is considered a risk factor for the development of many diseases in both adolescence and adulthood. It has been reported that chronic stress (for instance, due to maternal separation during breast feeding), causes damage to the central nervous system at the level of neurons and glial cells, which are reflected in behavioral disturbances and susceptibility to the development of primarily emotional psychopathology. The aim of this review is to identify the overall state of the scientific literature that relates the information about the consequences of early life stress, contextualizing the mechanisms that may be altered, the behavioral consequences that have been studied and the possible dimorphic effects and its causes. At the end a short overview of pharmacological treatments that have been proposed to reduce the behavioral and neuroendocrine consequences caused by early life stress is presented. This review pretends to integrate general but relevant information based primarily on studies in animal models, which allow the experimental approach and the study of the mechanisms involved. A series of questions remains for reflection and surely will be answered in the near future.

Maternal separation during nursing alters basal neuroendocrine levels in juvenile and adult rats.

INTRODUCTION: Work with different animal models including that of maternal separation during nursing has shown that early adverse experiences such as abuse, maternal abandonment and psychosocial stress may favor the development of various psychopathologies. However, several neuroendocrine changes have not been completely described yet.  OBJECTIVE: To establish whether maternal separation during nursing modifies the basal levels of neurohormones such as corticosterone, ACTH, oxytocin and vasopressin in juvenile and adult rats (aged 35 and 90 days, respectively).  MATERIALS AND METHODS: Wistar rats were separated from their mothers for two periods of 3 hours per day during the 21 days of nursing. Once these rats had reached 35 and then 90 days of age, blood samples were taken from both the separated and control groups to obtain serum for immunoenzymatic assays and measure the levels of each of the hormones.  RESULTS: Concentrations of corticosterone were higher in control adult females in comparison with the rest of the groups and lower in the control adult males. Those of ACTH were higher in the separated young males and females than in the adult groups. Oxytocin levels were significantly higher in the separated adult females in comparison with the other groups and significantly lower in the adult males. With respect to vasopressin, the separated groups had lower concentrations than the young and adult control groups.  CONCLUSIONS: These results show that the early stress to which rats were submitted produced changes in the basal responses of the hypothalamic-pituitary-adrenal axis, that these responses were distinct in males and females and that they also differed according to age.

La separación materna durante la lactancia altera los niveles basales del sistema neuroendocrino en ratas adolescentes y adultas / Maternal separation during nursing alters basal neuroendocrine levels in juvenile and adult rats

Introducción. En diversos modelos animales, incluido el de la separación materna durante la lactancia, se ha demostrado que las experiencias tempranas adversas, como el maltrato, el abandono materno y el estrés psicosocial, pueden favorecer el desarrollo de algunas enfermedades mentales, pero no se han descrito completamente varios de los cambios que se producen en el sistema neuroendocrino. Objetivo. Determinar si la separación materna durante la lactancia modificaba los niveles basales de neurohormonas como la corticosterona, la corticotropina (ACTH), la oxitocina y la vasopresina (ADH), en ratas jóvenes (35 días) y adultas (90 días). Materiales y métodos. Se separaron ratas Wistar de sus madres durante dos periodos de tres horas diarias a lo largo de los 21 días de lactancia. A los 35 y 90 días se tomaron muestras de los grupos de las ratas de control y de las separadas de la madre, para obtener el suero y posteriormente medir cada una de las hormonas mediante un ensayo inmunoenzimático. Resultados. Las concentraciones de corticosterona fueron mayores en las hembras adultas de control que en el resto de los grupos, y menores en los machos adultos de control. Las de ACTH fueron mayores en los machos y hembras jóvenes separadas de la madre que en los grupos de adultos. Los niveles de oxitocina fueron significativamente mayores en las hembras adultas separadas de la madre que en los otros grupos y significativamente menores en los machos adultos. En cuanto a la vasopresina, los grupos separados de la madre tuvieron concentraciones menores, en comparación con los grupos de jóvenes y adultos de control. Conclusiones. Estos resultados muestran que el estrés temprano al que fueron sometidas las ratas, produjo cambios en las respuestas del eje hipotálamo-hipófisis-suprarrenal, las cuales variaron según el sexo y la edad.

Introduction: Work with different animal models including that of maternal separation during nursing has shown that early adverse experiences such as abuse, maternal abandonment and psychosocial stress may favor the development of various psychopathologies. However, several neuroendocrine changes have not been completely described yet. Objective: To establish whether maternal separation during nursing modifies the basal levels of neurohormones such as corticosterone, ACTH, oxytocin and vasopressin in juvenile and adult rats (aged 35 and 90 days, respectively). Materials and methods: Wistar rats were separated from their mothers for two periods of 3 hours per day during the 21 days of nursing. Once these rats had reached 35 and then 90 days of age, blood samples were taken from both the separated and control groups to obtain serum for immunoenzymatic assays and measure the levels of each of the hormones. Results: Concentrations of corticosterone were higher in control adult females in comparison with the rest of the groups and lower in the control adult males. Those of ACTH were higher in the separated young males and females than in the adult groups. Oxytocin levels were significantly higher in the separated adult females in comparison with the other groups and significantly lower in the adult males. With respect to vasopressin, the separated groups had lower concentrations than the young and adult control groups. Conclusions: These results show that the early stress to which rats were submitted produced changes in the basal responses of the hypothalamic-pituitary-adrenal axis, that these responses were distinct in males and females and that they also differed according to age.

Efecto de la alopregnanolona sobre la ansiedad en ratas con separación materna durante la lactancia / The effect of allopregnanolone on anxiety induced in rats separated from their young during breastfeeding

Antecedentes. La relación madre-hijo y el cuidado parental al recién nacido son fundamentales en el desarrollo fisiológico y emocional de los individuos. Evidencias asocian el estrés temprano con el desarrollo de enfermedades mentales. El modelo de separación materna durante la lactancia (SMDL) se ha utilizado para inducir estrés temprano en ratas y estudiar efectos a largo plazo. Diversos estudios han encontrado que, en ratas separadas de sus madres, disminuyen los niveles del receptor GABA-A y esos bajos niveles están asociados a comportamientos ansiosos. Objetivo. Evaluar el efecto de la alopregnanolona, un neuroesteroide agonista del receptor GABA-A, sobre la ansiedad inducida por SMDL. Materiales y métodos. Se utilizaron 30 ratas Wistar dividas en dos grupos, uno control y uno experimental (SMDL). La SMDL se realizó desde el día postnatal 1 hasta el día postnatal 21, durante 180 minutos en la mañana y 180 minutos en la tarde. Desde el día 22 los sujetos se alojaron en cajas por sexo y tratamiento y continuaron su desarrollo normal hasta el día 60, en el que se hizo la inyección con alopregnanolona y la prueba comportamental en el laberinto en cruz elevado. Resultados. El estrés crónico causado por la SMDL afecta el comportamiento de los individuos, perfil comportamental que varía dependiendo del sexo. Se encontró que los machos presentan comportamientos más ansiosos que las hembras, las cuales a su vez muestran más actividad locomotora y exploración Conclusiones. Al aplicar alopregnanolona el repertorio comportamental varía en los animales con SMDL; estos resultados sugieren que la alopregnanolona, a través de su unión al receptor GABA-A, puede llegar a revertir los efectos de la separación materna, sobre los comportamientos relacionados con ansiedad.

Background. The mother-child relationship and parental care for the newborn are fundamental in individuals' physiological and emotional development. Evidence-based research associates early stress with the development of mental illnesses. Maternal separation during lactation (MSDL) models have been used to induce early stress in rats and for studying the long-term effects of such intervention. Several studies have found decreased GABA-A receptor levels in separated rats from their mothers and such low levels have been associated with anxious behaviour. Objective. Assessing the effect of allopregnanolone (a GABA-A receptor neurosteroid agonist) on MSDL-induced anxiety. Materials and methods. Thirty Wistar rats were divided into two groups: control and experimental (MSDL). SMDL occurred for 180 minutes in the morning and 180 minutes in the afternoon. Subjects were housed in boxes by gender and treatment following day 22 and their normal development was allowed to continue until day 60 when they were injected with allopregnanolone and underwent a behavioural test in an elevated plus maze (EPM). Results. Chronic stress induced by MSDL affected individuals' behaviour, their behavioural profile varying according to their gender. Males exhibited more anxious behaviour than females who engaged in more locomotive and exploratory activity. Conclusions. MSDL animals' behavioural repertoire varied due to the allopregnanolone injection, suggesting that the effect of allopregnanolone due to GABA-A receptor interaction could reverse the effects of maternal separation on anxiety-related behaviour.

Impacto de la separación materna durante la lactancia sobre el tamaño del cerebro y la inmunorreacción al receptor Gaba ­ A / Impact of maternal separation during nursing on brain size and onGABA-Areceptorimmunoreactivity

Introducción. El vínculo materno es fundamental para el establecimiento y mantenimiento de las redes sinápticas, y el desarrollo morfofisiológico y emocional de los individuos. Los niños maltratados o rechazados son más propensos a desarrollar psicopatologías. Los modelos animales permiten una aproximación experimental a mecanismos involucrados en alteraciones ocasionadas por estrés temprano. Objetivo. Determinar si la separación materna durante la lactancia, afecta en el adulto el tamaño del cerebro y el número de células inmunorreactivas a la subunidad alfa 1 del recep-tor ácido gamma-aminobutírico: GABA-A. Métodos. Se mantuvieron ratas Wistar con ciclo invertido luz-oscuridad, sin restricciones de agua o comida. Durante la lactancia, a unas mamás les fueron separadas las crías dos veces al día y otras se mantuvieron como grupo control. El día 22 los sujetos se separaron por sexo y tratamiento. El día 60 se perfundieron con paraformaldehído, previa anestesia, y los cere-bros fueron extraídos y pesados. Para identificar el tamaño cerebral, se hicieron cinco cortes seriados de 20 µm cada 100 µm. Se tomaron fotografías y se utilizó una escala micrométrica. La inmunorreacción al receptor GABA-A se analizó en cortes de 20 µm mediante tinción por inmunohistoquímica. Resultados. En las ratas adultas, el peso cerebral total de las ratas separadas fue menor. En las hembras separadas se observó reducción estadísticamente significativa en el tamaño del hipocampo. En los machos separados se observó disminución de la marcación para la subunidad alfa1 del receptor GABA-A, en la corteza prefrontal, la amígdala y el hipocampo. Conclusiones. Estos resultados muestran que la separación materna durante la lactancia altera, en ciertas áreas cerebrales del adulto, el tamaño y la inmunorreacción al receptor GABA-A, y que estos cambios son diferentes en hembras y machos

Introduction: The maternal bond is crucial to establish and maintain synaptic networks and for morphophysiological and emotional development of individuals. Neglected or abused kids are more susceptible to develop psychopathologies. Animal models allow an experimen-tal approach to mechanisms involved in alterations due early stress. Objective:To determine if maternal separation during nursing alters brain size in adults and the amount of immunoreactive cells to alpha subunit of GABA-A receptor. Methods: Wistar rats were kept under reverse light-dark cycle with food and water ad libitum. During nursing, pups were separated from their mothers twice a day and other group was used as control. At day 22nd, subjects were separated by gender and treatment. In day 60, subjects were anesthetized and perfused with paraformaldehyde and brains were extracted and weighted. In order to identify brain size, 5 serial slides of 20 µm were made every 100 µm. Pictures were taken and micrometric scale was used. Immunoreactivity to alpha subunit of GABA-A receptor was analyzed in 20 µm slides through immunohistochemistry. Results: In adults, total brain weight of separated rats was inferior thanin the control group. Separated females showed a significant reduction of hippocampus size. In separated males a decrease of immunoreactivity to GABA-A receptor in prefrontal cortex, amygdala and hip-pocampuswas evidenced. Conclusions: These results show that maternal separation during nursing alterssize in some brain areas of adult rats, the immunoreactivity to alpha subunit of GABA-A receptor, and these changes are different between separated females and males.

La ketamina mejora la supervivencia en ratas con quemaduras severas vía la expresión de la proteína de choque térmico 70, ¿cerca o lejos de la perspectiva clínica? / Ketamine improves survival in severe burn injury in rats via the expression of heat shock protein 70, far or close to the clinical perspective?

El presente comentario o escrito de reflexión tiene por objetivo señalar, en el artículo de investigación titulado «Ketamine improves survival in severe burn injury in rats via the expres-sion of heat shock protein 70¼, algunos aspectos que, sin pretender demeritar el trabajo de los investigadores, pudieran ser tenidos en cuenta a futuro, en aras de implementar posteriormente diseños experimentales que puedan contribuir de la mejor forma a fortalecer el vínculo entre la investigación biomédica básica y la clínica. Esta reflexión es de carácter netamente constructivo, procurando motivar en cada uno de quienes de una u otra manera mantienen un vínculo con la investigación, el desarrollo de un mejor análisis y propuesta de diseño experimental que permita proyectar resultados obtenidos en modelos animales, hacia una aplicabilidad clínica, manteniendo un número reducido de sujetos de trabajo, sin con ello quitarle validez a un estudio y buscando aprovechar de la mejor manera el ente de experimentación y el vínculo de la investigación básica con la clínica. En efecto, las pautas éticas emitidas por el Council for International Organizations of Medical Sciences, en su aparte referido a la experimentación con animales, instan en que la validez de un estudio permite mantener al mínimo el número de animales a utilizarse en un experimento. El artículo sobre el cual se hace esta reflexión fue publicado por Zhang Meng-yuan y colaboradores y se concluye que la terapia con ketamina mejora la sobrevivencia en heridas con quemaduras severas vía la expresión de proteínas de choque térmico en miocardio y cerebro.

The purpose ofthis reflectionorcommentary is notto demerit the efforts of the researchers, but rather to highlight some aspects that should be taken into account in the future for implementing experimental designs that may potentially contribute to strengthen the links between basic biomedical and clinical research, referring to the research article entitled Ketamine improves survival in severe burn injury in rats via the Expression of Heat Shock Protein 70. This is a purely constructive reflection aimed at encouraging those who are one way or other involved in research, to develop a more comprehensive analysis and a proposal for an experimental design that enables the extrapolation of the results from animal models to a clinical application, with a limited number of subjects but preserving the validity of the trial, in addition to making the best possible use of the experimental subjects and of there lationship between basic and clinical research. In fact, the ethical guidelines issued by the Councilfor International Organizations of Medical Sciences, in its chapteron animal experiments emphasize that the validity of a trial allows for using the minimum number of animals in an experiment. The article that makes reference to this matter was published by Zhang Meng-yuan et al., and concludes that Ketamine therapy improves the survival of patients with severe burn injuries via the expression of heat shock proteins in the heart and the brain.

Maternal Separation during Breastfeeding Induces Gender-Dependent Changes in Anxiety and the GABA-A Receptor Alpha-Subunit in Adult Wistar Rats.

Different models of rodent maternal separation (MS) have been used to investigate long-term neurobiological and behavioral changes, associated with early stress. However, few studies have involved the analysis of sex-related differences in central anxiety modulation. This study investigated whether MS during breastfeeding affected adult males and females in terms of anxiety and brain GABA-A receptor-alpha-subunit immunoreactivity. The brain areas analyzed were the amygdale (AM), hippocampus (HP), medial prefrontal cortex (mPFC), medial preoptic area (POA) and paraventricular nucleus (PVN). Rats were housed under a reversed light/dark cycle (lights off at 7∶00 h) with access to water and food ad libitum. Animals underwent MS twice daily during the dark cycle from postnatal day 1 to postnatal day 21. Behavior was tested when rats were 65-70 days old using the elevated plus maze and after brains were treated for immunohistochemistry. We found that separated females spent more time in the open arms and showed more head dipping behavior compared with controls. The separated males spent more time in the center of the maze and engaged in more stretching behavior than the controls. Immunohistochemistry showed that separated females had less immunostained cells in the HP, mPFC, PVN and POA, while separated males had fewer immunolabeled cells in the PFC, PVN and AM. These results could indicate that MS has gender-specific effects on anxiety behaviors and that these effects are likely related to developmental alterations involving GABA-A neurotransmission.

Maternal separation during breastfeeding induces changes in the number of cells immunolabeled to GFAP

The mother-child relationship is fundamental to the establishment and maintenance of synaptic networks and physiological and emotional development. Animal models including maternal separation have been used to study changes at behavioral and neurobiochemical levels. Due to the relevance of glial cells during development, our aim was to determine if short periods of maternal separation during breastfeeding induce permanent changes in a number of astrocytes labeled with the glial fibrillary acidic protein in different brain areas. Wistar rats were housed under standard laboratory conditions with reversed light/dark cycle; food and water ad libitum. Pups were separated from their mothers for 6 h daily during breastfeeding period. On day 22, pups were separately housed according to gender and treatment. At day 60, subjects were evaluated in the elevated plus maze and, after processing for immunohistochemistry, 20-μm sections were made. Prefrontal cortex, paraventricular nucleus, preoptic area, hippocampus and amygdala were localized. Labeled cells were quantified using Image-J program. Results showed that separated females had more entries into open arms and spend more time as compared with the control groups. In the prefrontal cortex we identified a decrease in staining cells in separated females, whereas there was an increase in staining cells in separated males. In the hippocampus and preoptic area, we observed a decrease only in separated males. We did not find any differences in the paraventricular nucleus or amygdala. Our results indicate that maternal separation during breastfeeding induces permanent changes in the number of astrocytes in different brain areas of both males and females.(AU)

Maternal separation during breastfeeding induces changes in the number of cells immunolabeled to GFAP

The mother-child relationship is fundamental to the establishment and maintenance of synaptic networks and physiological and emotional development. Animal models including maternal separation have been used to study changes at behavioral and neurobiochemical levels. Due to the relevance of glial cells during development, our aim was to determine if short periods of maternal separation during breastfeeding induce permanent changes in a number of astrocytes labeled with the glial fibrillary acidic protein in different brain areas. Wistar rats were housed under standard laboratory conditions with reversed light/dark cycle; food and water ad libitum. Pups were separated from their mothers for 6 h daily during breastfeeding period. On day 22, pups were separately housed according to gender and treatment. At day 60, subjects were evaluated in the elevated plus maze and, after processing for immunohistochemistry, 20-μm sections were made. Prefrontal cortex, paraventricular nucleus, preoptic area, hippocampus and amygdala were localized. Labeled cells were quantified using Image-J program. Results showed that separated females had more entries into open arms and spend more time as compared with the control groups. In the prefrontal cortex we identified a decrease in staining cells in separated females, whereas there was an increase in staining cells in separated males. In the hippocampus and preoptic area, we observed a decrease only in separated males. We did not find any differences in the paraventricular nucleus or amygdala. Our results indicate that maternal separation during breastfeeding induces permanent changes in the number of astrocytes in different brain areas of both males and females.

Diferencias en los comportamientos asociados con la ansiedad de ratas macho y hembra expuestas a un protocolo de estrés crónico por separación maternal temprana / Differences in behavior associated to anxiety in male and female rats exposed to a chronic stress protocol: early maternal separation

En mamíferos, durante las primeras etapas de la vida, el medio ambiente y la interacción madrehijoson esenciales para el normal desarrollo neuronal y comportamental. En efecto, se ha demostradoque la interrupción de esta interacción ejerce efectos tardíos sobre el desarrollo del sistemanervioso central, endocrino, inmune y el comportamiento. El objetivo de este estudio fue determinarel efecto de la Separación Maternal Temprana (SMT) sobre los comportamientos asociados con laansiedad en machos y hembras adultas utilizando el laberinto en cruz elevado (LCE). El protocolode SMT se llevó a cabo entre los días posnatales 1 y 21 separando las crías de sus madres dosveces al día (tres horas en la mañana y tres en la tarde). Como grupo control se utilizaron animalesde la misma camada que no fueron separados pero que fueron manipulados por un periodo de unminuto en la mañana y en la tarde. En el día posnatal 22 los animales se distribuyeron de acuerdoal sexo y se mantuvieron en el laboratorio sin ninguna manipulación hasta el día posnatal 90,cuando fue llevada a cabo la prueba comportamental en el laberinto en cruz elevado. Fueron evaluadosel número de entradas y el tiempo de permanencia en cada brazo y la frecuencia y el tiempoen las conductas de estirarse, agacharse y acicalarse. Nuestros resultados muestran que las hembras separadas tienen mayor número de entradas y se demoran más tiempo en los brazos abiertos,más agaches y menos acicalamientos comparados con los comportamientos de las hembras controly los machos experimentales y controles. De acuerdo con el perfil ansiolítico que muestran lashembras en el LCE nuestros datos sugieren que utilizando este protocolo, la SMT afectadiferencialmente a las hembras y a los machos adultos.

During the first stages of life, the environment and maternal interactions are essential for normalmammalian neuronal maturity and behavior. In fact, it has been demonstrated that disruption ofmother-pup interaction during early life exert long-lasting effects on the development of centralnervous, endocrine, and immune systems and behavioral responses. The principal aim of our workwas to study the consequences of early maternal separation (EMS) on adult male and female anxiety.The behaviors was evaluated using the Elavated Plus-Maze (EPM). Separation procedure was carriedout in postnatal days 1 to 21 twice daily: three hours in the morning and three hours in the afternoon.As a control group we used animals that stayed with the mother but were manipulated daily for oneminute in the morning and in the afternoon. In postnatal day 22, animals were distributed by sexand then kept in standard lab conditions. Behavioral testing in the EPM was performed at 90/95days of age. All subjects were videotaped. Records included number of entries, time spent in eacharm, and the frequency and time stretching, deeping, rearing, and grooming. Our results showedthat separated females have more open arm entries and spent more time there, and exhibit moredeeping and less grooming compared to females in the control group and males of the experimentaland control group. Thus, based on the anxiolytic profile that female rat shows in the EPM, thesedata suggest that EMS affects differentially male and female adult rats.

Properties of glutamate receptors of Alzheimer's disease brain transplanted to frog oocytes.

It is known that Alzheimer's disease (AD) is a synaptic disease that involves various neurotransmitter systems, particularly those where synaptic transmission is mediated by acetylcholine or glutamate (Glu). Nevertheless, very little is known about the properties of neurotransmitter receptors of the AD human brain. We have shown previously that cell membranes, carrying neurotransmitter receptors from the human postmortem brain, can be transplanted to frog oocytes, and their receptors will still be functional. Taking advantage of this fact, we have now studied the properties of Glu receptors (GluRs) from the cerebral cortices of AD and non-AD brains and found that oocytes injected with AD membranes acquired GluRs that have essentially the same functional properties as those of oocytes injected with membranes from non-AD brains. However, the amplitudes of the currents elicited by Glu were always smaller in the oocytes injected with membranes from AD brains. Western blot analyses of the same membrane preparations used for the electrophysiological studies showed that AD membranes contained significantly fewer GluR2/3 subunit proteins. Furthermore, the corresponding mRNAs were also diminished in the AD brain. Therefore, the smaller amplitude of membrane currents elicited by Glu in oocytes injected with membranes from an AD brain is a consequence of a reduced number of GluRs in cell membranes transplanted from the AD brain. Thus, using the comparatively simple method of microtransplantation of receptors, it is now possible to determine the properties of neurotransmitter receptors of normal and diseased human brains. That knowledge may help to decipher the etiology of the diseases and also to develop new treatments.