Chronic early-life stress increases cognitive impulsivity and D2 immunoreactivity in the nucleus accumbens of adult rats.

Chronic early life stress (ECS) induced by limited bedding and nesting (LBN) material in rodents is a naturalistic stress model that mimics many of the behavioral and neural consequences of child abuse and neglect; however, the effect of ECS on adult impulsivity has never been studied. The aim of our work was to determine the effects of ECS on cognitive impulsivity and its relation to D2 immunoreactivity in the nucleus accumbens (NAc) and prefrontal cortex (PFC) of adult male rats. Sprague-Dawley rats were exposed to LBN from postnatal day 2 to 9. We evaluated dams' maternal behavior and offspring corticosterone levels. The rats' impulsive cognitive behavior was evaluated by a delay-discounting task (transitional bridge) on P70, and we evaluated D2 receptors by immunostaining. Our results indicated that ECS affected maternal behavior in the dams and increased pups' corticosterone levels at P9, but not in adults. ECS rats showed lower frequencies of choosing the delayed reinforcer and shorter latencies to cross on the delay-discounting task. In addition, ECS rats showed increased D2 immunoreactivity in the NAc when compared with controls. Our data suggest that ECS can cause impulsive behaviors in adult rats characterized by less convenient choices, likely related to an increase in D2 receptors in the NAc. These findings could contribute to our understanding of the effects of child abuse and neglect on impulsive behavior.

Effect of Sexual Arousal on Cortical Coupling During Performance of the Tower of Hanoi Task in Young Men.

Sexual arousal affects cognitive processing, which depends on the coordinated functioning among cortical areas. The aim of this research was to determine whether previous observation of videos with sexual content affects the degree of cortical electroencephalographic (EEG) coupling during performance of an executive task. Cortical EEG correlations were calculated in three groups of heterosexual men under three conditions: at rest; during observation of a video with neutral, aggressive, or erotic content; and while performing the Tower of Hanoi task (TOH). Based on self-reports, it was shown that the erotic video induced general and sexual arousal, while the aggressive video affected valence and general arousal. Task performance was similar in all three groups. During performance of TOH, only the erotic group showed a decreased correlation between prefrontal areas with an increased correlation between parietal and prefrontotemporal areas, specifically in the slow bands. It is likely that these changes in the degree of cortical coupling could be associated with the cognitive strategies or functional adaptations that participants require to adequately solve the task during a state of sexual arousal. These data could contribute to improving our understanding of the central nervous mechanisms that underlie the effect of sexual arousal on the cognitive processes involved in tasks like TOH.

[Effect of alcohol on electrical organisation in the brain during a visuospatial working memory task and its relationship with the menstrual cycle]. / Efecto del alcohol en la organización eléctrica cerebral durante una tarea de memoria de trabajo visuoespacial y su relación con el ciclo menstrual.

INTRODUCTION: The metabolism of alcohol and cognitive functions can vary during the menstrual cycle. Also, both alcohol ingestion and hormonal variations during menstruation have been associated with characteristic changes in electroencephalographic (EEG) activity. AIM. To determine whether EEG activity during a working memory task is affected by acute alcohol consumption, and if these EEG patterns vary in relation to different phases of the menstrual cycle. SUBJECTS AND METHODS: 24 women who drank a moderate dose of alcohol or placebo during the follicular and early luteal phases of the menstrual cycle. The EEG activity was recorded during performance of viso-spatial working memory task. RESULTS: Although the alcohol did not deteriorate the performance of working memory task, it caused in the EEG a decrease of relative theta power and lower right fronto-parietal correlation in theta and alpha2 bands. Only women who drank alcohol in the follicular phase had a higher relative potency of alpha1, which could indicate a lower level of arousal and attention. CONCLUSIONS: These results contribute to a better understanding of the brain mechanisms underlying cognitive changes with alcohol and its relationship to the menstrual cycle.

TITLE: Efecto del alcohol en la organizacion electrica cerebral durante una tarea de memoria de trabajo visuoespacial y su relacion con el ciclo menstrual.Introduccion. El metabolismo del alcohol y el desempeño de muchas funciones cognitivas pueden variar a lo largo del ciclo menstrual. Tanto la ingestion de alcohol como las variaciones hormonales durante el ciclo menstrual se asocian con cambios caracteristicos en la actividad electroencefalografica. Objetivo. Determinar si la actividad electroencefalografica durante una tarea de memoria de trabajo es afectada por el consumo agudo de alcohol, y si dicha actividad varia en funcion del ciclo menstrual. Sujetos y metodos. Muestra de 24 mujeres que ingirieron alcohol o placebo durante las fases folicular y lutea temprana. Se registro el electroencefalograma durante la ejecucion de una tarea de memoria de trabajo visuoespacial. Resultados. Aunque el alcohol no deterioro el rendimiento de la tarea de memoria de trabajo, si produjo en el electroencefalograma una disminucion de la potencia relativa de theta y una menor correlacion frontoparietal derecha en las bandas theta y alfa2. Unicamente las mujeres alcoholizadas en la fase folicular presentaron una mayor potencia relativa de alfa1, que podria indicar menor nivel de alertamiento y atencion. Conclusiones. Estos resultados contribuyen a una mejor comprension de los mecanismos cerebrales que subyacen a los cambios cognitivos con el alcohol y su relacion con el ciclo menstrual.

Effects of alcohol on the performance of the Tower of London task in relation to the menstrual cycle: an electroencephalographic study.

It is well known that the metabolism of alcohol and cognitive functions can vary during the menstrual cycle. Also, both alcohol ingestion and hormonal variations during menstruation have been associated with characteristic changes in electroencephalographic (EEG) activity. The aim of the present study was to determine whether EEG activity during the performance of the Tower of London (TOL) task is affected by previous ingestion of alcohol and whether these EEG patterns vary in relation to different phases of the menstrual cycle. For this purpose, female participants consumed a moderate dose of alcohol or placebo during the follicular and early luteal phases of the menstrual cycle and then, 35 min after liquid ingestion, EEG activity was recorded during the performance of TOL. A deleterious effect of alcohol on TOL performance was potentiated in the follicular phase, related to a higher α1 relative power, probably as a result of the low progesterone levels characteristic of this menstrual phase. These data show the feasibility of examining the interaction of alcohol and menstrual cycle phases on cognitive performance by means of EEG recording, and contribute toward a better understanding of the brain mechanisms that underlie the cognitive changes that occur during the menstrual cycle under the effects of alcohol.

Effects of red wine on the electrical activity and functional coupling between prefrontal-parietal cortices in young men.

The effects of low-dose red wine on cortical electroencephalogram (EEG) and the functional coupling between the frontal and parietal cortices during the first minutes after ingestion were studied. In a first experiment, 38 male volunteers participated in a wine/water challenge protocol in which each subject served as his own control. Wine-induced EEG changes appeared immediately after ingestion and continued for 40 min. These changes were characterized by an increase in the absolute power (AP) and relative power (RP) of fast frequencies (alpha1, alpha2, beta1 and beta2), a decrease of low frequencies (delta and theta) and a specific decrease in the degree of coupling between cortices at 20 min after wine ingestion. To determine if EEG changes were produced by the alcohol in the red wine, in a second experiment, 24 male volunteers participated in an independent wine/placebo group protocol. At 20 min post-ingestion, the red wine group showed higher power in the alpha band, lower RP of low frequencies and decreased correlation, as compared to the placebo group. These findings show that low-dose red wine produces a rapid cortical activation and decreased synchronization between the prefrontal and parietal areas, which could be associated with aroused states or altered cognitive processes, as has been described in other studies.

Influencia del nivel educativo de los padres, el tipo de escuela y el sexo en el desarrollo de la atención y la memoria / Effects of parents' educational level, school type and gender on the development of attention and memory

La información sobre el efecto que ejercen las variables medioambientales en el desarrollo de la atención y la memoria es limitada. En este estudio se analizó la relación entre el nivel educativo de los padres, el tipo de escuela y el sexo en el desarrollo de la atención y la memoria. Participaron 476 niños (5 a 16 años) de escuelas públicas (EPu) y privadas (EPr) divididos en dos grupos de edad (G1 = 5 a 8 años y G2 = 9 a 16 años). Se analizaron las 15 sub-pruebas de la Evaluación Neuropsicológica Infantil-ENI que evalúan atención y memoria. Se encontró un efecto significativo de la edad en todas las pruebas: a mayor edad, mejor ejecución. También hubo un efecto significativo del sexo y el tipo de escuela en algunas tareas, donde las niñas superan a los varones y los estudiantes de EPr superan a los de EPu. Hubo una interacción significativa entre el tipo de escuela y el sexo: las niñas de EPr muestran mayor ejecución que el resto de los grupos en algunas tareas de atención y memoria, especialmente las que implican información verbal. Además hubo una correlación significativa entre el nivel educativo de los padres y la ejecución (9 a 16 años). Los hijos de padres con mayor escolaridad muestran mayor ejecución que aquéllos con padres de menor escolaridad. Los resultados se discuten en términos del impacto que ejercen las variables medioambientales en el desarrollo neuropsicológico.

Information about the influence of environmental factors on the development of attention and memory is scarce. This study analyzed the relationship between parents' educational level, school type and sex on the development of attention and memory. Four hundred and seventy six children (age 5 to 16 years) of public (PuS) and private schools (PrS) participated. The sample was divided in two age groups: G1, age 5 to 8 years and G2, age 9 to 16 years. Attention and memory sub-tests from the Evaluación Neuropsicológica Infantil-ENI (Matute, Rosselli, Ardila and Ostrosky, 2007) were analyzed. There was a significant effect of age on all sub-tests scores where older children obtained higher scores. Also, there was a significant effect of sex and type of school in some tasks, where girls had higher performance than boys and, the students of PrS scored higher than students of PuS. An interaction between type of school and sex was also evident: PrS girls show edhigher performance than other groups in some tasks of attention and memory, especially those that imply verbal information processing. There was a significant correlation between the parents’ educational level and the performance in G2. Sons of parents with high educational level show better performance than sons of parents with low educational level. The results are discussed in terms of the environmental variables effect on the development of attention and memory.