Sleep loss and addiction.

Reducing sleep hours is a risk factor for developing cardiovascular, metabolic, and psychiatric disorders. Furthermore, previous studies have shown that reduction in sleep time is a factor that favors relapse in addicted patients. Additionally, animal models have demonstrated that both sleep restriction and sleep deprivation increase the preference for alcohol, methylphenidate, and the self-administration of cocaine. Therefore, the present review discusses current knowledge about the influence of sleep hours reduction on addictivebehaviors; likewise, we discuss the neuronal basis underlying the sleep reduction-addiction relationship, like the role of the orexin and dopaminergic system and neuronal plasticity (i.e., delta FosB expression). Potentially, chronic sleep restriction could increase brain vulnerability and promote addictive behavior.

Análisis de trayectoria de las creencias patriarcales y sexistas, actitudes favorables a la violencia y violencia en el noviazgo / [Trajectory analysis of patriarchal and sexist beliefs, attitudes favorable to violence and dating violence]

El objetivo de esta investigación fue analizar las relaciones entre las creencias patriarcales y sexistas, las actitudes favorables a la violencia física, psicológica y sexual hacia las mujeres y hacia los hombres, y la presencia de la violencia en el noviazgo. Participaron 774 universitarios mexicanos (52,33% mujeres). Los resultados mostraron que los hombres han desarrollado más actitudes favoreciendo el uso de la violencia física, psicológica y sexual en contra de las mujeres a partir de la influencia de las creencias patriarcales y sexistas. Las mujeres con mayor adhesión a las creencias patriarcales y sexistas presentaron más actitudes favorables a la violencia física, psicológica y sexual hacia ellas mismas. Las mujeres que tuvieron puntuaciones más altas en las actitudes que favorecen la violencia hacia ellas tuvieron un mayor nivel de victimización. En conclusión, los cuatro modelos de análisis de trayectorias revelaron el impacto que tienen las creencias patriarcales y sexistas en la violencia en el noviazgo por medio de las actitudes que favorecen la violencia hacia las mujeres y hacia los hombres.

Dating violence research needs to examine the perspective and experience that women and men have of this type of violence and the cognitive factors associated with it. In order to fill this gap, the objective of this research was to analyze the relations between patriarchal and sexist beliefs, attitudes favorable to physical, psychological, and sexual violence towards women and men, and the prevalence of dating violence. A total of 774 Mexican university students (52.33% women and 47.67% men) participated answering five instruments. In order to examine the data obtained, four path analysis models were created. The results showed that men have developed more attitudes supporting the use of physical, psychological, and sexual violence against women from the influence of patriarchal and sexist beliefs. Likewise, women who reported greater adherence to patriarchal and sexist beliefs presented more favorable attitudes towards physical, psychological, and sexual violence towards themselves. In turn, it was found that female participants who reported higher scores in the attitudes supporting sexual, psychological, and sexual violence towards themselves had a higher level of victimization. In conclusion, the four models revealed the impact that patriarchal and sexist beliefs have on dating violence through attitudes supporting violence towards women and men.

Maternal Separation Modifies the Activity of Social Processing Brain Nuclei Upon Social Novelty Exposure.

Maternal separation has been shown to disrupt proper brain development and maturation, having profound consequences on the neuroendocrine systems in charge of the stress response, and has been shown to induce behavioral and cognitive abnormalities. At the behavioral level, maternal separation has been shown to increase offensive play-fighting in juvenile individuals and reduce social interest in adulthood. Since most of the studies that have evaluated the consequences of maternal separation on social behavior have focused on behavioral analysis, there is a need for a further understanding of the neuronal mechanisms underlying the changes in social behavior induced by maternal separation. Therefore, the aim of the present research was to assess the long-term effects of maternal separation on social interaction behavior and to assess the activity of several brain regions involved in the processing of social cues and reward upon social novelty exposure, using c-Fos immunohistochemistry as a marker of neuronal activity. Male Wistar rats were subjected to 4 h maternal separation during the neonatal period, 9:00 h-13:00 h from postnatal day 1 to 21, and exposed to social novelty during adulthood. After social novelty exposure, brains were fixed and coronal sections of the medial amygdala, lateral septum (LS), paraventricular nucleus of the hypothalamus, nucleus accumbens, and medial prefrontal cortex were obtained for c-Fos immunohistochemistry. Maternally separated rats spent less time investigating the novel peer, suggesting that maternal separation reduces social approach motivation. Furthermore, maternal separation reduced the number of c-Fos positive cells of the medial amygdala, paraventricular nucleus of the hypothalamus, LS, nucleus accumbens, and medial prefrontal cortex upon social novelty exposure. These findings suggest that maternal separation can reduce the plastic capacity of several brain nuclei, which constitute a physiological basis for the emergence of behavioral disorders presented later in life reported to be linked to early life adversity.

Lower ΔFosB expression in the dopaminergic system after stevia consumption in rats housed under environmental enrichment conditions.

Environmental enrichment (EE) has been proven to reduce drug seeking and the development of addiction-related behaviors in rodent models, but the effects of EE on natural reward acquisition in the form of sweet beverages are poorly understood. Accumulating evidence shows that the intake of sugar, the main ingredient of sweet beverages, alters the dopaminergic system, leading to addiction-related physiological and molecular changes. Sugar in sweet beverages has been replaced with natural sweeteners, such as stevia extract, which has greater sweetener potential but no energy content. Our research group found that sucralose consumption increased the expression of ΔFosB in reward-related nuclei, suggesting activation of the dopaminergic system. The present study assessed the effects of EE on stevia consumption and the expression of ΔFosB in the nucleus accumbens, caudate putamen, and prefrontal cortex. Sixteen male Wistar rats, 21 days old, were randomly assigned to an EE group (n = 8) or standard environment (SE) group (n = 8) and reared for 30 days. On postnatal day 52 (PND52), the brains of four animals in each housing condition were extracted to determine basal ΔFosB levels. Stevia consumption with intermittent access and ΔFosB immunoreactivity were measured for 21 days in the remainder of the rats. Compared with SE animals, EE animals exhibited a reduction of stevia consumption and alterations of ΔFosB immunoreactivity in the reward system. These results indicate that EE reduces stevia consumption and the stevia-induced ΔFosB expression, suggesting addiction-related changes in dopaminergic nuclei, which may be interpreted as a neuroprotective effect.

The mediating role of emotion regulation strategies in the relationship between family of origin violence and intimate partner violence.

The effects of family of origin violence and intimate partner violence have been extensively documented; however, very few studies have examined the interaction with emotion regulation strategies. Thus, the objective of this research was to analyze whether different types of emotion regulation strategies, both adaptive and maladaptive, mediate the relationship between family of origin violence and intimate partner violence in the Mexican population. A total of 838 participants (45.9% men and 54.1% women) responded to instruments addressing family of origin violence, emotion regulation strategies, and intimate partner violence. The results revealed that both structural models were significant. For women, the model showed an adequate fit X2 (11, N = 838) = 22.75, p = .288, GFI = .95, AGFI = .91, NFI = .98, CFI = .97, RMSEA = .05. Likewise, we found similar indexes for men X2 (11, N = 838) = 28.20, p = .348, GFI = .97, AGFI = .93, NFI = .97, CFI = .95, RMSEA = .04. Specifically, the direct effects of adaptive strategies on intimate partner violence were statistically significant. Meanwhile, the direct effects of family of origin violence on maladaptive emotion regulation strategies were significant, as were the direct effects of maladaptive strategies on intimate partner violence. In turn, the indirect effects of family of-origin violence were significantly related to intimate partner violence via maladaptive emotion regulation strategies. In addition, the results clearly showed that men reported higher levels of aggression against women. Finally, regarding the selection of emotion regulation strategies, while women employed more adaptive emotion regulation, men showed a more definite tendency to use maladaptive emotion regulation.

Creencias sobre la violencia y sus efectos en la prevalencia de la violencia en el noviazgo / Beliefs about violence and its effects on the prevalence of dating violence

Resumen La violencia en el noviazgo es un fenómeno multifactorial que requiere de estudios que profundicen respecto a los efectos que tienen las creencias culturales en el comportamiento tanto del agresor como de la víctima. Teniendo esto en cuenta, el objetivo de la presente investigación fue determinar la relación entre las creencias acerca de la violencia y la prevalencia de la violencia en el noviazgo. Para ello, se contó con una muestra de 420 estudiantes de dos universidades públicas mexicanas que respondieron el Inventario de creencias acerca de la violencia hacia la esposa, el Inventario de conflictos en las relaciones de noviazgo, y un cuestionario de información sociodemográfica. Los datos recolectados fueron examinados por medio de un análisis de correlación canónica, y los resultados mostraron que el modelo en general fue estadísticamente significativo (Wilks X = .654, F(20, 677.54) = 4.626,p < .05); que el tamaño del efecto del modelo general fue de .346, lo que indica que este explicó el 34.6 % de la varianza compartida por los dos conjuntos de variables; y que, específicamente en la primera función, el coeficiente de mayor magnitud fue el de la variable de justificación de la violencia (r2 s = 76.2; h 2 = 90.0), seguido por la del apoyo que se le puede brindar a la víctima (r2 s = 57.1; h2 = 94.5).

Abstract Dating violence is a multifactorial phenomenon that requires in-depth studies regarding the effects that cultural beliefs have on the behavior of both the aggressor and the victim. With this in mind, the objective of this research was to determine the relationship between beliefs about violence and the prevalence of dating violence. To this end, a sample of 420 students from two Mexican public universities answered the Inventory of Beliefs about Wife Violence, the Inventory of Conflicts in Dating Relationships, and a sociodemographic information questionnaire. The data collected were examined through a canonical correlation analysis, and the results showed that the overall model was statistically significant (Wilks X = .654, F (20, 677.54) = 4.626, p < .05); that the effect size of the overall model was .346, indicating that it explained 34. 6 % of the variance shared by the two sets of variables; and that, specifically in the first function, the coefficient of greatest magnitude was that of the variable of justification of the violence (r2 s = 76.2; h2 = 90.0), followed by that of the support that can be given to the victim (r2 s = 57.1; h2 = 94.5).

The mediating role of emotion regulation strategies in the relationship between family of origin violence and intimate partner violence

Abstract The effects of family of origin violence and intimate partner violence have been extensively documented; however, very few studies have examined the interaction with emotion regulation strategies. Thus, the objective of this research was to analyze whether different types of emotion regulation strategies, both adaptive and maladaptive, mediate the relationship between family of origin violence and intimate partner violence in the Mexican population. A total of 838 participants (45.9% men and 54.1% women) responded to instruments addressing family of origin violence, emotion regulation strategies, and intimate partner violence. The results revealed that both structural models were significant. For women, the model showed an adequate fit X 2 (11, N = 838) = 22.75, p = .288, GFI = .95, AGFI = .91, NFI = .98, CFI = .97, RMSEA = .05. Likewise, we found similar indexes for men X2 (11, N = 838) = 28.20, p = .348, GFI = .97, AGFI = .93, NFI = .97, CFI = .95, RMSEA = .04. Specifically, the direct effects of adaptive strategies on intimate partner violence were statistically significant. Meanwhile, the direct effects of family of origin violence on maladaptive emotion regulation strategies were significant, as were the direct effects of maladaptive strategies on intimate partner violence. In turn, the indirect effects of family of-origin violence were significantly related to intimate partner violence via maladaptive emotion regulation strategies. In addition, the results clearly showed that men reported higher levels of aggression against women. Finally, regarding the selection of emotion regulation strategies, while women employed more adaptive emotion regulation, men showed a more definite tendency to use maladaptive emotion regulation.

Un modelo multidimensional de la violencia escolar en México: factores familiares y psicológicos / A multidimensional model of school violence in Mexico: family and psychological factors

El objetivo de este trabajo fue analizar la relación entre las disfunciones familiares, la violencia escolar y algunos trastornos psicológicos, particularmente la depresión, la ansiedad y el estrés. Participaron 388 adolescentes mexicanos de entre 14 y 19 años de edad. Con la finalidad de examinar los efectos que tienen los factores familiares en la violencia escolar, así como las consecuencias de esta violencia en la salud mental de los adolescentes, se construyó un modelo de ecuaciones estructurales. Debido a que el modelo original no se ajustó de forma adecuada a los datos, se reespecificó mostrando de esta manera un ajuste global adecuado con los datos. Los resultados indican que los problemas en la comunicación y la falta de apoyo por parte de los padres fueron los dos predictores más significativos en la violencia escolar y la experiencia de victimización. Además, la depresión, el estrés y la ansiedad presentaron, de mayor a menor magnitud, una relación positiva con la variable latente de trastornos psicológicos (AU)

The objective of this research was to analyze the relationship between family dysfunctions, bullying, and some psychological disorders, particularly depression, anxiety, and stress. A total of 388 Mexican adolescents between 14 and 19 years of age participated in this study. In order to examine the effects that family factors have on bullying, as well as the consequences of this violence on the mental health of adolescents, a structural equation model was constructed. Since the original model did not fit the data adequately, it was re-specified. Consequently, this new model shows an adequate global fit with the data. Results indicate that communication problems and lack of parental support were the two most significant predictors of bullying and the experience of victimization. In addition, depression, stress, and anxiety presented, from greater to lesser magnitude, a positive relation with the latent variable of psychological disorders (AU)

Anandamide and sucralose change ΔFosB expression in the reward system.

Food reward has been studied with highly palatable stimuli that come from natural additives such as sucrose. The most common food additive is sucralose, a noncaloric sweetener present in many food products of daily intake. The role of anandamide [N-arachidonylethanolamide (AEA)], an endogenous cannabinoid, has been widely studied in food behavior. Studies have shown that cannabinoids, such as AEA, 2-Arachidonilglycerol, and Tetrahydrocannabinol, can provoke hyperphagia, because they enhance the preference and intake of sweet and high-fat food. Taste perception is mediated by receptors taste type 1 receptor 3 (T1R3); therefore, there could be a synergistic effect between receptors CB1 and T1R3. This could explain why cannabinoids could change sweet taste perception and therefore the activity of neural nuclei involved in taste and reward. In this study, we evaluated the activity of dopaminergic nuclei implicated in food reward after the chronic administration of AEA (0.5 mg/kg bw) and sucralose intake (0.02%). We analyzed the expression of ΔFosB by immunohistochemistry. Our results show that the chronic administration of AEA and sucralose intake induces an overexpression of ΔFosB in the infralimbic cortex (Cx), nucleus accumbens (NAc) core, shell, and central nucleus of amygdala (Amy). These results suggest that the possible interaction between receptors CB1 and T1R3 has consequences not only in taste perception but also that AEA intervenes in the activity of dopaminergic nuclei such as the NAc, and that the chronic administration AEA and sucralose intake induce long-term changes in the reward system.

Pharmacological Regulation in the USA and Pharmacokinetics Parameters of Firocoxib, a Highly Selective Cox-2, by Pain Management in Horses.

The objective of the study was to conduct a review of the pharmacological regulation and pharmacokinetic parameters of firocoxib when administered orally or intravenously in horses. A search for literature was done in SCOPUS and PubMed for studies that had to evaluate the pharmacological regulation as well as the pharmacokinetic parameters of firocoxib when administered in horses. The nonsteroidal anti-inflammatory drugs have analgesic, anti-inflammatory, antipyretics, and antiendotoxic effects. The newly developed is selective to COX2 characterized by less adverse effects in veterinary patients when administered at the recommended doses and do not exceed the established prescribed time. Firocoxib is authorized by the Food and Drug Administration for the treatment of pain in horses, whereas for humans, there is still no approval. Controversy has arisen because the administration of the same pharmaceutical presentation in horses and dogs has pharmacokinetic differences between animal species. However, special attention must be paid to pharmacokinetic differences between species like in horses and dogs. In the case of the horse, the dosage is 0.1 mg/kg in single dose or up to 14 days in oral paste formulation and can keep maintained on the same concentration for a period of 7-14 days in oral tablet formulation. Thorough knowledge of pharmacological regulations and pharmacokinetic parameters, it allows the posology and effective application of firocoxib in pathologies associated with chronic pain, avoiding the indiscriminate use by owners and in some cases veterinarians, thus reducing the negative impacts on horse's health.

c-Fos immunoreactivity in the hypothalamus and reward system of young rats after social novelty exposure.

Socialization is an adaptive behavior during the early stages of life because it helps young animals become independent and determines healthy adult social behavior. Therefore, it is probable that the brain areas involved in the processing of social stimuli are more sensitive to social novelty during early life stages. To test this hypothesis, four groups of young male rats were exposed to different socioenvironmental stimuli; nonsocial physical novelty, social familiarity, social novelty, and a control group which received no stimulation. After stimuli exposure, brains were fixed and cut in coronal sections for c-Fos immunohistochemistry. The number of c-Fos-immunoreactive (c-Fos-ir) neurons in the paraventricular nucleus and supraoptic nucleus, the main producers of oxytocin and vasopressin, was compared, as well as in the nucleus accumbens and ventral pallidum, the main areas involved in reinforced behavior. A significantly higher number of c-Fos-ir neurons were found in animals exposed to social novelty in all areas, except in the supraoptic nucleus. In particular, the increase in c-Fos-ir in the paraventricular nucleus seems to be selective in response to social novelty, while the increase of c-Fos-ir in the nucleus accumbens and ventral pallidum suggests that social novelty during youth is a highly rewarding stimulus compared with social familiarity and nonsocial physical novelty.

Enriched environment attenuates nicotine self-administration and induces changes in ΔFosB expression in the rat prefrontal cortex and nucleus accumbens.

Environment enrichment conditions have important consequences on subsequent vulnerability to drugs of abuse. The present work examined whether exposure to an enriched environment (EE) decreases oral self-consumption of nicotine. Wistar rats were housed either in a standard environment (SE, four rats per standard cage) or in an EE during 60 days after weaning. EE consisted of eight animals housed in larger cages containing a variety of objects such as boxes, toys, and burrowing material that were changed three times a week. After this period, animals were exposed to nicotine for 3 weeks, where animals chose freely between water and a nicotine solution (0.006% in water). Fluid consumption was evaluated on a daily basis. ΔFosB immunohistochemistry in the prefrontal cortex and nucleus accumbens was also performed. Rats of the EE group consumed less nicotine solution (0.25±0.04 mg/kg/day) than SE rats (0.54±0.05 mg/kg/day). EE increased the number of ΔFos-immunoreactive (ΔFos-ir) cells in the nucleus accumbens core and shell and in the prefrontal cortex, compared with animals in the standard condition. However, rats exposed to nicotine in the SE showed higher ΔFos-ir cells in the nucleus accumbens core and shell than nonexposed rats. Nicotine consumption did not modify ΔFos-ir cells in these brain areas in EE animals. These results support the idea of a possible protective effect of the EE on reward sensitivity and the development of an addictive behavior to nicotine.

Sleep deprivation reduces neuroglobin immunoreactivity in the rat brain.

Neuroglobin (Ngb), a protein located in the mammal's brain, is involved in oxygen transport and free radical scavenging inside the neurons. Ngb colocalizes with choline acetyltransferase in the laterodorsal tegmental nucleus and in the pontine tegmental nucleus, both involved in the sleep-wake cycle regulation. Some studies have shown that free radicals accumulated during prolonged wakefulness are removed during sleep. Therefore, Ngb could act as a regulator of free radicals generated during prolonged wakefulness in the brain. The aim of this study was to determine whether prolonged wakefulness affects Ngb immunoreactivity because of increases in the oxidative stress induced by continuous neuronal activity. For this purpose, male adult Wistar rats were implanted with electrodes for sleep recordings and were divided into control and sleep-deprived groups. Sleep deprivation was carried out for 24 h by gentle handling of the animals. Sleep-wake activity was determined during the deprivation period or 24 h of control conditions. Subsequently, both groups of animals were killed and their brains were obtained and processed for Ngb immunohistochemical analysis and detection of lipid peroxidation. Our data found no evidence of increased oxidative stress in the brains of sleep-deprived animals compared with the controls. The number of Ngb-positive cells was decreased in the sleep-deprived animals in all analyzed areas of the brain compared with the control group. Our results suggest that Ngb could be involved in sleep regulation, independent of its role in the control of oxidative stress.

Sleep-inducing factors.

Kuniomi Ishimori and Henri Piéron were the first researchers to introduce the concept and experimental evidence for a chemical factor that would presumably accumulate in the brain during waking and eventually induce sleep. This substance was named hypnotoxin. Currently, the variety of substances which have been shown to alter sleep includes peptides, cytokines, neurotransmitters and some substances of lipidic nature, many of which are well known for their involvement in other biological activities. In this chapter, we describe the sleep-inducing properties of the vasoactive intestinal peptide, prolactin, adenosine and anandamide.