The role of personality dimensions, depressive symptoms and other psychosocial variables in predicting postpartum suicidal ideation: a cohort study.

Suicidability has been associated with neuroticism and psychoticism, but its role during perinatal period has not been analyzed. We explore the association between personality dimensions, depressive symptoms, and other psychosocial variables in postpartum suicidal ideation. A cohort of 1795 healthy Spanish women from the general population was assessed for suicidal ideation (EPDS-Item10) in early postpartum, 8 and 32 weeks postpartum. Sociodemographic, obstetric, and reproductive variables, psychiatric history, social support, stressful life-events during pregnancy, depressive symptoms (EPDS), and the Eysenck's personality dimensions (EPQ-RS) were also assessed at baseline. A major depressive episode (DSM-IV) was confirmed in women with EPDS>10 at follow-up assessments. Descriptive, bivariate, and multivariate analyses were conducted. Adjusted logistic regression analysis was reported as odds ratio (ORs) with 95% confidence intervals (CIs). Seven percent of mothers reported suicidal ideation during the first 8 months postpartum. Sixty-two percent of women with suicidal ideation had a major depressive episode at 8 weeks, and 70% at 32 weeks postpartum. Neuroticism and psychoticism predicted suicidal ideation throughout the first 2 weeks after delivery (OR, 1.03; 95%CI 1.01-1.06; and OR, 1.03; 95%CI 1.01-1.05 respectively). Early postpartum depressive symptoms (OR 1.2; 95%CI 1.11-1.26), personal psychiatric history (OR 2.1; 95%CI 1.33-3.27), and stressful life events during pregnancy (OR 1.88; 95%CI 1.12-3.16) also emerged as predictors of postpartum suicidal ideation. Analysis of women for postpartum suicidal ideation should include not only psychiatric symptoms but also psychosocial assessment (i.e., covering psychiatric history, stressful events, or long-standing personality vulnerabilities) in order to identify those in need of early psychosocial or psychiatric care.

Deletion of α-neurexin II results in autism-related behaviors in mice.

Autism is a common and frequently disabling neurodevelopmental disorder with a strong genetic basis. Human genetic studies have discovered mutations disrupting exons of the NRXN2 gene, which encodes the synaptic adhesion protein α-neurexin II (Nrxn2α), in two unrelated individuals with autism, but a causal link between NRXN2 and the disorder remains unclear. To begin to test the hypothesis that Nrxn2α deficiency contributes to the symptoms of autism, we employed Nrxn2α knockout (KO) mice that genetically model Nrxn2α deficiency in vivo. We report that Nrxn2α KO mice displayed deficits in sociability and social memory when exposed to novel conspecifics. In tests of exploratory activity, Nrxn2α KO mice displayed an anxiety-like phenotype in comparison with wild-type littermates, with thigmotaxis in an open field, less time spent in the open arms of an elevated plus maze, more time spent in the enclosure of an emergence test and less time spent exploring novel objects. However, Nrxn2α KO mice did not exhibit any obvious changes in prepulse inhibition or in passive avoidance learning. Real-time PCR analysis of the frontal cortex and hippocampus revealed significant decreases in the mRNA levels of genes encoding proteins involved in both excitatory and inhibitory transmission. Quantification of protein expression revealed that Munc18-1, encoded by Stxbp1, was significantly decreased in the hippocampus of Nrxn2α KO mice, which is suggestive of deficiencies in presynaptic vesicular release. Our findings demonstrate a causal role for the loss of Nrxn2α in the genesis of autism-related behaviors in mice.

Mesenchymal stromal-cell transplants induce oligodendrocyte progenitor migration and remyelination in a chronic demyelination model.

Demyelinating disorders such as leukodystrophies and multiple sclerosis are neurodegenerative diseases characterized by the progressive loss of myelin that may lead toward a chronic demyelination of the brain's white matter, impairing normal axonal conduction velocity and ultimately causing neurodegeneration. Current treatments modifying the pathological mechanisms are capable of ameliorating the disease; however, frequently, these therapies are not sufficient to repress the progressive demyelination into a chronic condition and permanent loss of function. To this end, we analyzed the effect that bone marrow-derived mesenchymal stromal cell (BM-MSC) grafts exert in a chronically demyelinated mouse brain. As a result, oligodendrocyte progenitors were recruited surrounding the graft due to the expression of various trophic signals by the grafted MSCs. Although there was no significant reaction in the non-grafted side, in the grafted regions oligodendrocyte progenitors were detected. These progenitors were derived from the nearby tissue as well as from the neurogenic niches, including the subependymal zone and dentate gyrus. Once near the graft site, the cells matured to myelinating oligodendrocytes. Finally, electrophysiological studies demonstrated that axonal conduction velocity was significantly increased in the grafted side of the fimbria. In conclusion, we demonstrate here that in chronic demyelinated white matter, BM-MSC transplantation activates oligodendrocyte progenitors and induces remyelination in the tissue surrounding the stem cell graft.

Association between neonatal temperament, SLC6A4, DRD4 and a functional polymorphism located in TFAP2B.

Genetic studies on human personality have provided little satisfactory results to date mainly because of the complexity of this trait. Neonatal temperament using observational measures is an alternative phenotype to approach genetics to human behavior. An association study was conducted on 117 Caucasian newborns. Their temperament was evaluated using the Neonatal Behavior Assessment Scale 48 h after birth. Thirteen polymorphisms in the SLC6A4, DRD4 and TFAP2B genes were genotyped. Linear regression was performed to analyze data, and Bonferroni correction was applied. To check the functional effect of the TFAP2B Indel Intron 2 polymorphism, reporter gene luciferase assays using a mouse cortical neural progenitor cell line and quantitative polymerase chain reaction (qPCR) studies in human post-mortem brain samples were performed. A significant association was found between 5-HTTLPR, 5-HTTLPR + rs25531 and TFAP2B Indel Intron 2 with Range of State cluster as well as an interaction between rs25531 and TFAP2B Indel Intron 2 with Range of State. DRD4 variable number tandem repeat exon 3 was associated with orientation. A 30% increase in the luciferase levels of the TFAP2B 5-repeat alleles compared with the 6-repeat alleles (P-value = 0.03) was found using the pGL3 promoter vector. The qPCR experiments showed the same trend as the in vitro studies, although no significant results were obtained. This study supports a role of the SLC6A4, DRD4 and TFAP2B genes in the temperament, including a gene-gene interaction between SLC6A4 and TFAP2B. It also provides evidence about an effect of the TFAP2B polymorphism in TFAP2B gene transcription.

Mood changes after delivery: role of the serotonin transporter gene.

BACKGROUND: Polymorphic variations in the serotonin transporter gene (5-HTT) moderate the depressogenic effects of tryptophan depletion. After childbirth there is a sharp reduction in brain tryptophan availability, thus polymorphic variations in 5-HTT may play a similar role in the post-partum period. AIMS: To study the role of 5-HTT polymorphic variations in mood changes after delivery. METHOD: One thousand, eight hundred and four depression-free Spanish women were studied post-partum. We evaluated depressive symptoms at 2-3 days, 8 weeks and 32 weeks post-partum. We used diagnostic interview to confirm major depression for all probable cases. Based on two polymorphisms of 5-HTT (5-HTTLPR and STin2 VNTR), three genotype combinations were created to reflect different levels of 5-HTT expression. RESULTS: One hundred and seventy-three women (12.7%) experienced major depression during the 32-week post-partum period. Depressive symptoms were associated with the high-expression 5-HTT genotypes in a dose-response fashion at 8 weeks post-partum, but not at 32 weeks. CONCLUSIONS: High-expression 5-HTT genotypes may render women more vulnerable to depressive symptoms after childbirth.