Candidate gene study reveals DRD1 and DRD2 as putative interacting risk factors for youth depression.

Alterations in the monoaminergic neurotransmission systems are suspected to be involved in the etiology of neuropsychiatric disorders, including depression. The role of these pathways in the risk of developing depressive symptoms during childhood or adolescence is still not completely clear. This study sought to identify putative genetic factors in genes of serotonergic and dopaminergic systems modulating the level of manifestation of depressive symptoms in children and adolescents. We analyzed 170 single nucleotide polymorphisms (SNPs) in 21 candidate dopaminergic and serotonergic genes in a non-clinical sample of 410 Costa Rican participants of ages between 7 and 18 years, assessing the severity of depressive symptoms through the Child Depression Inventory (CDI). Genotypic and haplotypic associations, as well as epistatic effects, were examined. A significant interaction effect was detected between rs1039089 in conjunction with rs877138 located upstream of the dopamine D1 receptor (DRD1) and the dopamine D2 receptor (DRD2) genes respectively, although no evidence was found for any single variant or haplotype related to a differential liability. This newly described genetic interaction among putative regulatory regions of dopamine receptors could affect the level of manifestation of depressive symptoms through an imbalance of D1-D2 heteromers and modulation of cognitive processes.

Parental age effects, but no evidence for an intrauterine effect in the transmission of myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is caused by the expansion of an unstable CTG repeat (g.17294_17296(45_1000)) with more repeats associated with increased disease severity and reduced age at onset. Expanded disease-associated alleles are highly unstable in both the germline and soma. Germline instability is expansion biased, providing a molecular explanation for anticipation. Somatic instability is expansion biased, size- and age-dependent, features that have compromised genotype-phenotype correlations and intergenerational studies. We corrected these confounding factors by estimating the progenitor allele length in 54 father-offspring and 52 mother-offspring pairs in Costa Rican DM1 families. Not surprisingly, we found major parental allele length effects on the size of the allele transmitted, the magnitude of the intergenerational length change, the age at onset in the next generation and the degree of anticipation in both male and female transmissions. We also detected, for the first time, an age-of-parent effect for both male and female transmission. Interestingly, we found no evidence for an intrauterine effect in the transmission of congenital DM1, suggesting previous reports may have been an artefact of age-dependent somatic instability and sampling bias. These data provide new insights into the germline dynamics of the CTG repeat and opportunities for providing additional advice and more accurate risk assessments to prospective parents in DM1 families.

The implicit power motive and sociosexuality in men and women: Pancultural effects of responsibility.

Research has shown that an individual's implicit power motive relates to 2 types of behavioral clusters: either prosocial, socially appropriate behaviors or profligate, impulsive behaviors. The present study examined the relationship between individuals' implicit power motives and their tendency to engage in sexual activities without strong emotional ties (i.e., sociosexuality). For men, but not for women, this relationship was hypothesized to be moderated by an implicit disposition for responsibility. Whereas most research has been limited to Euro-American contexts, the present study examined the relationship between power motive, disposition for responsibility, and sociosexuality among participants recruited in Cameroon, China, Costa Rica, and Germany. Explicit Big Five measures of personality were controlled for. For women, only a main effect of responsibility on sociosexuality was found across cultural groups; for men, the association between power motivation and sociosexuality was moderated by responsibility, independent of cultural group. Traits of agreeableness and conscientiousness were systematically related to lower levels of sociosexuality. Effects for both implicit and explicit measures of personality suggest universality in the processes associated with more enactments of sociosexuality, confirming in part the hypothesized role of responsibility in channeling the realization of the power motive into less impulsive activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Concern for generativity and its relation to implicit pro-social power motivation, generative goals, and satisfaction with life: a cross-cultural investigation.

So far, cross-cultural research on generativity has been lacking. The present study tests the cross-cultural applicability of an integrative model of generativity proposed by McAdams and de St. Aubin. Measures of implicit pro-social power motivation, a general disposition for generativity, generative goals, and life satisfaction were administered to adults in Cameroon, Costa Rica, and Germany. These measures cover the intrapersonal part of the generativity model. After examining the comparability of the measures across the three cultures, cultural differences in the level of each variable were inspected. Finally, the hypothesized model was tested via structural equation modeling. Results show that the model can be successfully applied in all three cultural samples. This finding has interesting implications for the further investigation of generativity, particularly its social antecedents and behavioral consequences.

El hombre y la mujer ideal según adolescentes en Costa Rica y Alemania / The ideal man and woman according t. adolescents from Costa Rica and Germany

Adolescentes (N=696), entre 11 a 16 años de edad, 327 mujeres, 369 hombres, de Costa Rica y Alemania, evaluaron 40 características posibles de un hombre y una mujer ideal, utilizando una escala tipo likert de 7 puntos desarrollada por Gibbons, Brusi-Figueroa & Fisher (1997); además, dibujaron cómo se representarían a un hombre y una mujer ideal realizando una actividad en particular. La valoración de los dibujos se realizó utilizando el método y los criterios aplicados en otros estudios internacionales previos por Stues & Gibbons (1999). El análisis de componentes principales confirmó los dos factores encontrados en estudios anteriores: Personalidad Social y Atractivo Físico. Un ANOVA 2x2x2x6 (país x sexo del participante x sexo del ideal x edad) fue ejecutado para la Escala de Personalidad Social y la Escala de Atractivo Físico como variables dependientes. Las mujeres y los adolescentes costarricenses en general valoran más las cualidades sociales, que los varones y los adolescentes alemanes en general. La importancia promedio del atractivo físico fue mayor para los varones, en particular, para la mujer ideal de los varones costarricenses y para el hombre ideal de los varones alemanes. Las actividades del hombre y la mujer ideal reflejada en los dibujos fue más estereotipada con relación al sexo, y le dieron más relevancia a la maduración física en la muestra alemana; mientras que los adolescentes costarricenses enfatizaron más las relaciones sociales

Disruption of tactile discrimination in rats by bilateral stimulation of midbrain lemniscal pathways.

Bilateral stimulation in the midbrain medial lemniscus disrupted tactile discrimination in four of nine rats. Single conditioning shocks in the midbrain of these animals attenuated by more than 80% the somatosensory cortical evoked responses elicited by test shocks to the contralateral forepaw. Midbrain stimulation did not selectively disrupt discrimination in the remaining five rats, and midbrain conditioning shocks attenuated the cortical test response by less than 80% on at least one side. The four rats that showed disrupted discrimination and bilaterally strong attenuation of cortical responses also had both midbrain electrodes in or next to the medial lemniscus. The five rats that did not show these effects had at least one midbrain electrode away from that structure.