Sex-Specific Effects of Early Life Stress on Brain Mitochondrial Function, Monoamine Levels and Neuroinflammation

Sex differences have been reported in the susceptibility to early life stress and its neurobiological correlates in humans and experimental animals. However, most of the current research with animal models of early stress has been performed mainly in males. In the present study, prolonged maternal separation (MS) paradigm was applied as an animal model to resemble the effects of adverse early experiences in male and female rats. Regional brain mitochondrial function, monoaminergic activity, and neuroinflammation were evaluated as adults. Mitochondrial energy metabolism was greatly decreased in MS females as compared with MS males in the prefrontal cortex, dorsal hippocampus, and the nucleus accumbens shell. In addition, MS males had lower serotonin levels and increased serotonin turnover in the prefrontal cortex and the hippocampus. However, MS females showed increased dopamine turnover in the prefrontal cortex and increased norepinephrine turnover in the striatum, but decreased dopamine turnover in the hippocampus. Sex differences were also found for pro-inflammatory cytokine levels, with increased levels of TNF-α and IL-6 in the prefrontal cortex and hippocampus of MS males, and increased IL-6 levels in the striatum of MS females. These results evidence the complex sex- and brain region-specific long-term consequences of early life stress.This work was supported by grants PSI 2017-83038-P to HGP and NC, PSI 2017-90806-REDT to JLA, PSI 2017-83893-R to JLA (Ministry of Economy and Competitiveness, Spain)

Tolerancia al alcohol en ratas sometidas a diferentes períodos de consumo agudo y crónico de etanol

The development of tolerance to the effects of ethanol is not uniform and may vary according to the actual and previous pattern of consumption. In this experiment we assessed body temperature and the recovery of two reflexes after a high dose of ethanol in rats submitted to chronic and acute ethanol consumption. Animals were previously submitted to chronic or acute alcohol consumption from postnatal day 21 until postnatal days 56 and 84. On the testing days, the animals received a single dose of 25% ethanol (5 g/kg, i.p.) or the same amount of saline solution. The results showed that animals were affected in the day 56 to a greater extent than in the day 84 by chronic heavy consumption of ethanol solution. With moderate and acute ethanol consumption, the 56-day-old animals developed greater tolerance. However, tolerance was not developed for the motor-impairing effects, since all groups required a long time to recover reflexesEl desarrollo de tolerancia a los efectos del alcohol no es uniforme, y suele variar según el patrón de consumo previo y actual. En este trabajo se evaluó la temperatura corporal y el tiempo de recuperación de dos reflejos tras el consumo crónico y agudo de elevadas dosis de etanol. Previamente, los animales bebieron alcohol de forma crónica o aguda desde los 21 hasta los 56 y 84 días de edad. Durante los días de evaluación, los animales recibieron una única dosis de etanol al 25% (5 g/kg, i.p.), o la misma cantidad de solución salina. Los resultados mostraron una mayor afectación a los 56 días de consumo crónico elevado de etanol respecto a los 84 días. Con un consumo moderado o agudo de etanol, los animales de 56 días desarrollaron una mayor tolerancia. Sin embargo, esta tolerancia no se observó en cuanto a los déficits motores, dado que todos los grupos necesitaron un largo período de tiempo para recuperar los reflejosThis work was supported by grants PR78/02-10972 (Complutense University), MCYT BSO 2001-2757 (Ministry of Science and Technology, Spain) and PR-01-GE-2 (Principado de Asturias, Spain

Evidence for sexual difference in astrocytes of adult rat hippocampus

Abstract We quantified the number of glial fibrillary acidic protein immunoreactive (GFAP-IR) astrocytes in the CA1 and CA3 areas of the adult rat hippocampus. The dorsal and ventral regions of the hippocampus were taken into account to estimate the GFAP-IR cells using unbiased stereological techniques. Males had a higher number of GFAP-IR astrocytes in the CA3 area, whereas females had more in the CA1 area. No sex difference was found between dorsal and ventral regions, although most GFAP-IR astrocytes were located in the dorsal hippocampus. q 2003 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Glial fibrillary acidic protein; Hippocampus; Sex differences; Optical fractionator; Astrocytes; Rat The hippocampus represents a heterogeneous structure, functionally differentiated along its dorsoventral axis as recent behavioural studies suggest However, not only neurons but also glial cells are targets for sex hormones such as estrogen and testosterone The aim of the present study was to evaluate gender differences in the total number of GFAP-immunoreactive (GFAP-IR) astrocytes in CA1 and CA3 hippocampal areas, estimated by unbiased stereological counting methods. In particular, the dorsoventral anatomical subdivision of these hippocampal areas was taken into account. Adult male and female Wistar rats (3 months of age, n ¼ 6 per group) obtained from the University of Oviedo central vivarium were used. The animals were maintained on a 12:12 h light/dark cycle, and a temperature of 22^2 8C, with food and water available ad libitum. All experimental procedures followed strictly the EEC Council Directive 86/609 regarding the care and use of laboratory animals. Vaginal smears were taken from virgin females to determine the different stages of the estrous cycle. The subjects were selected at the morning of the proestrous phase. This arbitrary criterion was primarily chosen to avoid unpredictable variations in the results due to different levels of sex steroids in circulation. The rats were anaesthetized with sodium pentobarbital (70 mg/kg for males and 45 mg/kg for females, i.p.) and intracardially perfused with 0.9% saline in 0.1 M phosphate buffer (PBS; pH 7.4) followed by 10% phosphate-buffered 0304-3940/03/$ -see front matter

Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.This study was supported by grants from the Spanish Government (Ministerio de Economía y Competitividad and Instituto Mixto de Investigación-Escuela Nacional de Sanidad (IMIENS)) and the Fondo Europeo de Desarrollo Regional (MINECO-FEDER) Grant numbers: PSI2017-90806-REDT, PSI2017-83038-P, PSI2017-83893-R, PSI2017-86396-P, PSI2017-86847-C2-2-R MINECO-FEDER, and IMIENS: PIC-IMIENS-2018-003.S

Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health

Altered brain functional connectivity and behaviour in a mouse model of maternal alcohol binge-drinking

Prenatal and perinatal alcohol exposure caused by maternal alcohol intake during gestation and lactation periods can have long-lasting detrimental effects on the brain development and behaviour of offspring. Children diagnosed with Foetal Alcohol Spectrum Disorders (FASD) display a wide range of cognitive, emotional and motor deficits, together with characteristic morphological abnormalities. Maternal alcohol binge drinking is particularly harmful for foetal and early postnatal brain development, as it involves exposure to high levels of alcohol over short periods of time. However, little is known about the long-term effects of maternal alcohol binge drinking on brain function and behaviour. To address this issue, we used pregnant C57BL/6 female mice with time-limited access to a 20% v/v alcohol solution as a procedure to model alcohol binge drinking during gestation and lactational periods. Male offspring were behaviourally tested during adolescence (30 days) and adulthood (60 days), and baseline neural metabolic capacity of brain regions sensitive to alcohol effects were also evaluated in adult animals from both groups. Our results show that prenatal and postnatal alcohol exposure caused age-dependent changes in spontaneous locomotor activity, increased anxiety-like behaviour and attenuated alcohol-induced conditioned place preference in adults. Also, significant changes in neural metabolic capacity using cytochrome c oxidase (CCO) quantitative histochemistry were found in the hippocampal dentate gyrus, the mammillary bodies, the ventral tegmental area, the lateral habenula and the central lobules of the cerebellum in adult mice with prenatal and postnatal alcohol exposure. In addition, the analysis of interregional CCO activity correlations in alcohol-exposed adult mice showed disrupted functional brain connectivity involving the limbic, brainstem, and cerebellar regions. Finally, increased neurogenesis was found in the dentate gyrus of the hippocampus of alcohol-exposed offspring, suggesting neuroadaptive effects due to early alcohol exposure. Our results demonstrate that maternal binge-like alcohol drinking causes long-lasting effects on motor and emotional-related behaviours associated with impaired neuronal metabolic capacity and altered functional brain connectivity.This study was supported by grants from the EuropeanUnion's Horizon 2020 research and innovation programme 2014-2020under Grant Agreement No 634143, the Spanish Ministry of Economy,Innovation and Competitiveness (SAF2016-75966-R), the SpanishMinistryof Education and Science and Innovation and EuropeanRegional Development Fund (PSI2013-45924-P, PSI2015-73111-EXP, PSI2017-83038-P, PSI2017-83893-R, the Plan Nacional sobre Drogas(#2014/020), and the Plan de Ciencia, Tecnología e Innovación delPrincipado de Asturias (FC-15-GRUPIN14-088). Department ofExperimental and Health Sciences is a“Unidad de Excelencia María deMaeztu”funded by the MINECO (MDM-2014-0370). The authors de-clare no potential conflicts of interest

Altered brain functional connectivity and behaviour in a mouse model of maternal alcohol binge-drinking

Prenatal and perinatal alcohol exposure caused by maternal alcohol intake during gestation and lactation periods can have long-lasting detrimental effects on the brain development and behaviour of offspring. Children diagnosed with Foetal Alcohol Spectrum Disorders (FASD) display a wide range of cognitive, emotional and motor deficits, together with characteristic morphological abnormalities. Maternal alcohol binge drinking is particularly harmful for foetal and early postnatal brain development, as it involves exposure to high levels of alcohol over short periods of time. However, little is known about the long-term effects of maternal alcohol binge drinking on brain function and behaviour. To address this issue, we used pregnant C57BL/6 female mice with time-limited access to a 20% v/v alcohol solution as a procedure to model alcohol binge drinking during gestation and lactational periods. Male offspring were behaviourally tested during adolescence (30 days) and adulthood (60 days), and baseline neural metabolic capacity of brain regions sensitive to alcohol effects were also evaluated in adult animals from both groups. Our results show that prenatal and postnatal alcohol exposure caused age-dependent changes in spontaneous locomotor activity, increased anxiety-like behaviour and attenuated alcohol-induced conditioned place preference in adults. Also, significant changes in neural metabolic capacity using cytochrome c oxidase (CCO) quantitative histochemistry were found in the hippocampal dentate gyrus, the mammillary bodies, the ventral tegmental area, the lateral habenula and the central lobules of the cerebellum in adult mice with prenatal and postnatal alcohol exposure. In addition, the analysis of interregional CCO activity correlations in alcohol-exposed adult mice showed disrupted functional brain connectivity involving the limbic, brainstem, and cerebellar regions. Finally, increased neurogenesis was found in the dentate gyrus of the hippocampus of alcohol-exposed offspring, suggesting neuroadaptive effects due to early alcohol exposure. Our results demonstrate that maternal binge-like alcohol drinking causes long-lasting effects on motor and emotional-related behaviours associated with impaired neuronal metabolic capacity and altered functional brain connectivity.This study was supported by grants from the EuropeanUnion's Horizon 2020 research and innovation programme 2014-2020under Grant Agreement No 634143, the Spanish Ministry of Economy,Innovation and Competitiveness (SAF2016-75966-R), the SpanishMinistryof Education and Science and Innovation and EuropeanRegional Development Fund (PSI2013-45924-P, PSI2015-73111-EXP, PSI2017-83038-P, PSI2017-83893-R, the Plan Nacional sobre Drogas(#2014/020), and the Plan de Ciencia, Tecnología e Innovación delPrincipado de Asturias (FC-15-GRUPIN14-088). Department ofExperimental and Health Sciences is a“Unidad de Excelencia María deMaeztu”funded by the MINECO (MDM-2014-0370). The authors de-clare no potential conflicts of interest

Early-life stress induces emotional and molecular alterations in female mice that are partially reversed by cannabidiol

Gender is considered as a pivotal determinant of mental health. Indeed, several psychiatric disorders such as anxiety and depression are more common and persistent in women than in men. In the past two decades, impaired brain energy metabolism has been highlighted as a risk factor for the development of these psychiatric disorders. However, comprehensive behavioural and neurobiological studies in brain regions relevant to anxiety and depression symptomatology are scarce. In the present study, we summarize findings describing cannabidiol effects on anxiety and depression in maternally separated female mice as a well-established rodent model of early-life stress associated with many mental disorders. Our results indicate that cannabidiol could prevent anxiolytic- and depressive-related behaviour in early-life stressed female mice. Additionally, maternal separation with early weaning (MSEW) caused long-term changes in brain oxidative metabolism in both nucleus accumbens and amygdalar complex measured by cytochrome c oxidase quantitative histochemistry. However, cannabidiol treatment could not revert brain oxidative metabolism impairment. Moreover, we identified hyperphosphorylation of mTOR and ERK 1/2 proteins in the amygdala but not in the striatum, that could also reflect altered brain intracellular signalling related with to bioenergetic impairment. Altogether, our study supports the hypothesis that MSEW induces profound long-lasting molecular changes in mTOR signalling and brain energy metabolism related to depressive-like and anxiety-like behaviours in female mice, which were partially ameliorated by CBD administration.This work was supported by Ministerio de Economía y Competitividad (grants number PID2019-104077-RB-100 and PSI2017-83038-P), Ministerio de Sanidad, Asuntos Sociales e Igualdad (Retic-ISCIII-RD/16/0017/0010-FEDER) and Plan Nacional Sobre Drogas (#2018/007). The Department of Experimental and Health Sciences (UPF) is a “Unidad de Excelencia María de Maeztu” funded by the AEI (CEX2018-000792-M)