Stress is a prevailing risk factor for mood-related illnesses, wherein women represent the majority of those affected by major depression. Despite the growing literature suggesting that affective ...disorders can arise after a traumatic event is vicariously experienced, this relationship remains understudied in female subjects at the preclinical level. Thus, the objective of the current investigation was to examine whether exposure to emotional and/or psychological stress (ES) mediates depression-related outcomes in female mice.
Female C57BL/6 mice (8 weeks old, null parity) vicariously experienced the defeat bout of a male conspecific, by a male CD1 aggressor, for 10 consecutive days. Twenty-four hours after the last stress exposure, female mice were tested in the social interaction, sucrose preference, tail suspension, or elevated plus maze tests. Furthermore, we examined whether ketamine and chlordiazepoxide, pharmacological agents used to treat mood-related disorders in the clinical population, would reverse the ES-induced social dysfunction.
When compared with control mice, female mice exposed to ES displayed decreased social behavior and preference for sucrose, along with increased immobility in the tail suspension test. Also, they displayed higher levels of blood serum corticosterone, as well as decreased body weight. Lastly, the ES-induced avoidance-like phenotype was ameliorated by both ketamine and chlordiazepoxide.
Our data indicate that female mice exposed to ES display a behavioral and physiologic profile that mimics symptoms of depression in the clinical population. As such, this experimental model may be adopted to examine vicarious stress-induced mood-related disorders, as well as pharmacological antidepressant response, in a sex-specific manner.
Climate change is arguably the greatest challenge to conservation of our time. Most vulnerability assessments rely on past and current species distributions to predict future persistence but ignore ...species' abilities to disperse through landscapes, which may be particularly important in fragmented habitats and crucial for long‐term persistence in changing environments. Landscape genetic approaches explore the interactions between landscape features and gene flow and can clarify how organisms move among suitable habitats, but have suffered from methodological uncertainties. We used a landscape genetic approach to determine how landscape and climate‐related features influence gene flow for American pikas (Ochotona princeps) in Crater Lake National Park. Pikas are heat intolerant and restricted to cool microclimates; thus, range contractions have been predicted as climate changes. We evaluated the correlation between landscape variables and genetic distance using partial Mantel tests in a causal modelling framework, and used spatially explicit simulations to evaluate methods of model optimization including a novel approach based on relative support and reciprocal causal modelling. We found that gene flow was primarily restricted by topographic relief, water and west‐facing aspects, suggesting that physical restrictions related to small body size and mode of locomotion, as well as exposure to relatively high temperatures, limit pika dispersal in this alpine habitat. Our model optimization successfully identified landscape features influencing resistance in the simulated data for this landscape, but underestimated the magnitude of resistance. This is the first landscape genetic study to address the fundamental question of what limits dispersal and gene flow in the American pika.
Formation of long-term pair-bonds is a complex process, involving multiple neural circuits and is context- and experience-dependent. While laboratory studies using prairie voles have identified the ...involvement of several neural mechanisms, efforts to translate these findings into predictable field outcomes have been inconsistent at best. Here we test the hypothesis that inhibition of oestrogen receptor alpha (ERα) in the medial amygdala of male prairie voles would significantly increase the expression of social monogamy in the field. Prairie vole populations of equal sex ratio were established in outdoor enclosures with males bred for high levels of ERα expression and low levels of prosocial behaviour associated with social monogamy. Medial amygdala ERα expression was knocked down in half the males per population. Knockdown males displayed a greater degree of social monogamy in five of the eight behavioural indices assessed. This study demonstrates the robust nature of ERα in playing a critical role in the expression of male social monogamy in a field setting.
Ketamine has shown promising antidepressant efficacy for adolescent treatment-resistant depression. However, the potential enduring consequences of ketamine exposure have not been thoroughly ...evaluated. Thus, we examined if juvenile ketamine treatment results in long-lasting changes for the rewarding properties of sucrose and cocaine in adulthood, across three separate experiments. In Experiment 1, adolescent male and female C57BL/6 mice received ketamine (20 mg/kg) for 15 consecutive days (Postnatal Day PD 35-49). Twenty-one days later (PD70; adulthood) we examined their behavioral responsivity to sucrose (1%) on a two-bottle choice design, or cocaine (0, 5, 10 mg/kg) using the conditioned place preference (CPP) test. We found that juvenile ketamine-pretreatment increased preference for sucrose and environments paired with cocaine in male, but not female, adult mice. This long-term outcome was not observed when male and female mice received ketamine as adults (PD70-84) and tested for sucrose and cocaine preference 21-days later (Experiment 2). Similarly, in Experiment 3, no long-lasting differences in these measures were observed when adolescent male mice were exposed to concomitant ketamine and social stressors (PD35-44), namely the social defeat or vicarious defeat stress paradigms-procedures that mediated a depression-related phenotype (along with a ketamine antidepressant-like response). Collectively, we demonstrate that in the absence of physical or psychological stress, adolescent ketamine exposure increases later life preference for the rewarding properties of sucrose and cocaine in a sex- and age-specific manner. As such, this preclinical work provides awareness for the potential long-term behavioral consequences associated with juvenile ketamine exposure.
•Adolescent fluoxetine history impairs spatial memory in adult male mice.•Adolescent exposure to fluoxetine does not influence spatial memory in adult female mice.•Adolescent exposure to fluoxetine ...does not impact episodic memory in adulthood.
Epidemiological reports indicate that mood-related disorders are common in the adolescent population. The prevalence of juvenile major depressive disorder has resulted in a parallel increase in the prescription rates of fluoxetine (FLX) within this age group. Although such treatment can last for years, little is known about the enduring consequences of adolescent antidepressant exposure on memory-related performance.
We exposed separate groups of adolescent (postnatal day PD 35) male and female C57BL/6 mice to FLX (20 mg/kg) for 15 consecutive days (PD35-49). Three weeks after FLX exposure (PD70), we assessed learning and memory performance on a single-day training object novelty recognition test, or a spatial memory task on the Morris water maze (MWM).
We found that FLX pretreatment did not influence performance on either the object novelty recognition task or the MWM, 24 h after training. Conversely, 48 h post spatial-training on the MWM, FLX pretreated male mice spent significantly less time on the quadrant of the missing platform during a standard probe trial. No differences in MWM performance were observed in the adult female mice pretreated with FLX.
A limitation of this study is that normal adolescent mice (i.e., non-stressed) were evaluated for memory-related behavior three weeks after antidepressant exposure. Thus, it is possible that FLX pre-exposure in combination with animal models for the study of depression may yield different results.
Together, these results demonstrate enduring spatial memory-related deficiencies after pre-exposure to FLX during adolescence in male, but not female, C57BL/6 mice.
Background:
Preclinical evidence from male subjects indicates that exposure to psychotropic medications, during early development, results in long-lasting altered responses to reward-related stimuli. ...However, it is not known if exposure to the antidepressant fluoxetine, in female subjects specifically, changes sensitivity to natural and drug rewards, later in life.
Aims:
The aim of this work was to investigate if exposure to fluoxetine mediates enduring changes in sensitivity to the rewarding properties of cocaine and sucrose, using female mice as a model system.
Methods:
We exposed C57BL/6 female mice to fluoxetine (250 mg/L in their drinking water) for 15 consecutive days, either during adolescence (postnatal day 35–49) or adulthood (postnatal day 70–84). Twenty-one days later, mice were examined on their behavioral reactivity to cocaine (0, 2.5, 5, 7.5 mg/kg) using the conditioned place preference paradigm, or assessed on the two-bottle sucrose (1%) test.
Results:
We found that regardless of age of antidepressant exposure, female mice pre-exposed to fluoxetine displayed reliable conditioning to the cocaine-paired compartment. However, when compared to respective age-matched controls, antidepressant pre-exposure decreased the magnitude of conditioning at the 5 and 7.5 mg/kg cocaine doses. Furthermore, fluoxetine pre-exposure reduced sucrose preference without altering total liquid intake.
Conclusions:
The data suggest that pre-exposure to fluoxetine, during adolescence or adulthood, results in a prolonged decrease in sensitivity to the rewarding properties of both natural and drug rewards in female C57BL/6 mice.
Colorectal cancer (CRC) requires massive iron stores, but the complete mechanisms by which CRC modulates local iron handling are poorly understood. Here, we demonstrate that hepcidin is activated ...ectopically in CRC. Mice deficient in hepcidin specifically in the colon tumour epithelium, compared with wild-type littermates, exhibit significantly diminished tumour number, burden and size in a sporadic model of CRC, whereas accumulation of intracellular iron by deletion of the iron exporter ferroportin exacerbates these tumour parameters. Metabolomic analysis of three-dimensional patient-derived CRC tumour enteroids indicates a prioritization of iron in CRC for the production of nucleotides, which is recapitulated in our hepcidin/ferroportin mouse CRC models. Mechanistically, our data suggest that iron chelation decreases mitochondrial function, thereby altering nucleotide synthesis, whereas exogenous supplementation of nucleosides or aspartate partially rescues tumour growth in patient-derived enteroids and CRC cell lines in the presence of an iron chelator. Collectively, these data suggest that ectopic hepcidin in the tumour epithelium establishes an axis to sequester iron in order to maintain the nucleotide pool and sustain proliferation in colorectal tumours.
Transparent conductive oxide electrodes and specifically SnO
2
:F/glass are widely employed substrates in the preparation of optoelectronic devices. This study deals with the surface effect of ...commercially SnO
2
:F/glass electrodes on the properties of ZnO nanowires grown onto them by using an electrochemical method. Four types of commercially SnO
2
:F/glass with sheet resistances in the range of 7–15 Ω cm
−2
and roughness from 9 to 39 nm were used. The deposition process of ZnO nanowires was performed with zero, one, and two ZnO seed layers, respectively. The seed layer was grown from an ethanolic solution of zinc acetate as a Zn
2+
precursor, and further, a thermal treatment was performed. The formation of the nanomaterial was carried out by using the potentiostatic method at − 1 V and until reaching a total charge of − 1.5 C at a temperature of 75 °C. Different densities of nanowires were obtained for each case, with diameters ranging from 30 to 400 nm. The SnO
2
:F/glass roughness affects the diameter and alignment of the ZnO nanowires. Measurements of diffusive spectra in the optical range, as well as the determination of polarization properties, show that the seed layer deposition is indispensable to obtain optimal optical quality. The findings here discussed constitute another critical factor to be considered in the synthesis of well-aligned nanowires.
DIFERENCIAS EN LA CALIDAD DE VIDA DE ESTUDIANTES UNIVERSITARIOS DE DIFERENTE AÑO DE INGRESO DEL CAMPUS ANTUMAPU Durán A, Samuel(Universidad de Chile Instituto de Nutrición y Tecnología de los Alimentos (INTA)); Castillo A, Marcela(Universidad de Chile Instituto de Nutrición y Tecnología de los Alimentos (INTA)); Vio del R, Fernando(Universidad de Chile Instituto de Nutrición y Tecnología de los Alimentos (INTA))
Revista chilena de nutrición,
2009, Letnik:
36, Številka:
3
Journal Article
Odprti dostop
Life in university is a time of changes in education, social life, family, emotional and eating behaviors. Objective: To compare the quality of life and nutritional status in students of first year ...(PA) versus students of third o more (TA) years in the Antumapu Campus, University of Chile. We assessed 98 students, 52 of PA and 46 ofTA, which completed a survey of quality of life, anthropometric variables and food consumption. Students of PA hada better perception of quality of life, sexual activity, relationship with their couple and wellbeing. Alcohol consumption was greater in students ofTA than PA (10.6g vs 6gp<0,05, respectively). Women of PA had higher brachial circumference and lower waist circumference, bicipital and tricipital skin folds (p<0.05). These results shows than in the perception of quality of life exist differences between gender and years of staying in the university. Students of PA presented a lower consumption of tobacco, alcohol and better nutritional status than student ofTA.
El período universitario es una etapa de cambios educativos, sociales, familiares, alimentarios y emocionales. Objetivo: Comparar a estudiantes de primer año (PA) versus estudiantes de tres o más años de permanencia (TA) en el Campus Antumapu de la Universidad de Chile, en la valoración de su calidad de vida y estado nutritional. Método: Se evaluaron 98 estudiantes voluntarios, 52 de PA y 46 de TA y aplicándoles: una encuesta de calidad de vida y evaluación nutritional. Resultados: Los estudiantes de PA presentaron una mejor percepción en su vida sexual, pareja y bienestar. El consumo de alcohol era significativamente mayor en alumnos de TA 10,6 g vs PA 6 g (p<0,05). Estudiantes mujeres de PA presentan un mayor Perímetro Muscular Braquial, menor circunferencia de cintura y pliegues bicipital y tricipital (p<0,05). Conclusión: La percepción de calidad de su vida es diferente según sexo y año de ingreso, los estudiantes de PA presentan un menor consumo de alcohol y un estado nutritional más adecuado al comparados con los estudiantes de TA.
Changes in the polarization state of light due to its interaction (reflection and transmission) with samples of CuSCN nanorod and ZnO nanowire arrays are analyzed and compared following a recently ...proposed technique (Valente et al., 2019). The determination of the degree of polarization and measurements of diffusive light are used to investigate the influence of the morphology of nanorods and nanowires on the optical properties. It is shown that the CuSCN nanorods are better than ZnO nanowires to preserve polarization, although the degree of polarization decreases with the lengths for both materials. It is shown that the degree of polarization correlate with the diffusive light, which allow an estimation of the large scale uniformity of the samples. However, it is also shown that the loss of polarization quality can be present even in absence of diffusion, which indicates that the interferometric effect on the nanoscale should be an important cause of the depolarizing effect.
•The polarization properties of nanostructures are analyzed through Stokes parameters measurements.•Nanorods and nanowires are compared using partial polarized light.•Correlations between loss of polarization and scattered light are analyzed.•Diffuse light and the degree of polarization reveal global level of order.
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