Comparative Study of Regional Homogeneity in Schizophrenia and Major Depressive Disorder.

Comparative study of regional homogeneity in schizophrenia and major depressive disorder.

Filed under: Depression Treatment

Am J Med Genet B Neuropsychiatr Genet. 2012 Nov 20;
Chen J, Xu Y, Zhang K, Liu Z, Xu C, Shen Y, Xu Q

Compelling evidence suggests that there is a considerable overlap in structural and functional alternation in the brain between different neuropsychiatric disorders. However, whether these overlaps are specific for schizophrenia has yet to be investigated. A total of 36 patients with paranoid schizophrenia, 43 patients with major depressive disorder (MDD), and 44 healthy controls were recruited to undergo resting-state functional magnetic resonance imaging (rs-fMRI) for analysis of regional homogeneity (ReHo). Twelve regions of interest (ROIs) in the frontal and temporal lobes were generated and one-way ANOVA was performed to test the ReHo differences within these ROIs between the above three groups. The ReHo values within ROIs were extracted to investigate whether a left-right asymmetry existed in a mental disorder. One-way ANOVA showed significant differences in ReHo in the right superior frontal gyrus and left superior temporal gyrus; post hoc analysis revealed that schizophrenic patients had lower ReHo in the left superior temporal gyrus than either control subjects or patients with MDD. Increased ReHo was observed in the right superior frontal gyrus in schizophrenic patients compared with control subjects, and a left-less-than-right asymmetry was also found in this region in schizophrenic patients. The above alterations in ReHo were not affected by age and genders. Our study suggests that the altered ReHo in the superior frontal and temporal gyrus may be specific for schizophrenia rather than MDD. A left-less-than-right asymmetry activation pattern may exist in the resting-state superior frontal gyrus in schizophrenia. This finding would be helpful for better understanding the pathological mechanisms of schizophrenia. © 2012 Wiley Periodicals, Inc.
HubMed – depression

 

Inbreeding depression in urban environments of the bird’s nest fungus Cyathus stercoreus (Nidulariaceae: Basidiomycota).

Filed under: Depression Treatment

Heredity (Edinb). 2012 Nov 21;
Malloure BD, James TY

Many organisms display codispersal of offspring, but fewer display codispersal of compatible gametes. This mechanism enhances the ability of a species to colonize after long distance dispersal as a mechanism of reproductive assurance, but it also fosters inbreeding and potential reduction in fitness. Here we investigated both long distance dispersal and inbreeding in the bird’s nest fungus Cyathus stercoreus, a dung and mulch-associated fungus with a splash cup fruiting body appearing like a miniature bird’s nest of ‘eggs’ or peridioles that contain thousands of mating compatible meiotic spores. To investigate the genetic structure in the species, six North American urban populations were hierarchically sampled and genotyped using 10 microsatellite markers. We detected significant levels of inbreeding through heterozygote deficiencies at four loci, with global F(IS)=0.061. Dispersal limitation was suggested by both spatial autocorrelation and the detection of population structure between Louisiana and Michigan using clustering and F-statistics. Although inbreeding may facilitate colonization by the fungus, it has a negative effect on the fitness of populations as estimated from a 15% reduction in growth rates of inbred strains relative to outcrossed. Mating tests revealed that C. stercoreus has a higher estimated number of mating-type alleles (MAT-A= 39, MAT-B= 24) than other species of bird’s nest fungi, which would increase its outcrossing efficiency. We speculate that the increased number of mating-type alleles is the result of a recent range and population size expansion into urban environments.Heredity advance online publication, 21 November 2012; doi:10.1038/hdy.2012.95.
HubMed – depression

 

Glucocorticoid Receptor and FKBP5 Expression Is Altered Following Exposure to Chronic Stress: Modulation by Antidepressant Treatment.

Filed under: Depression Treatment

Neuropsychopharmacology. 2012 Nov 21;
Guidotti G, Calabrese F, Anacker C, Racagni G, Pariante CM, Riva MA

Major depression is thought to originate from the interaction between susceptibility genes and adverse environmental events, in particular stress. The hypothalamus-pituitary-adrenal (HPA) axis is the major system involved in stress response and its dysregulation is an important element in the pathogenesis of depression. The stress response is therefore finely tuned through a series of mechanisms that control the trafficking of glucocorticoid receptors (GRs) to the nucleus, including binding to the chaperone protein FKBP5 and receptor phosphorylation, suggesting that these elements may also be affected under pathologic conditions. On these bases, we investigated FKBP5 and GR expression and phosphorylation in the hippocampus (ventral and dorsal) and in the prefrontal cortex of rats exposed to chronic mild stress (CMS) and we analyzed the effect of a concomitant antidepressant treatment. We found that animals exposed to CMS show increased expression of FKBP5 as well as enhanced cytoplasmic levels of GR, primarily in ventral hippocampus and prefrontal cortex. Chronic treatment with the antidepressant duloxetine is able to normalize such alterations, mainly in the prefrontal cortex. Moreover, we demonstrate that CMS-induced alterations of GR trafficking and transcription may be sustained by changes in receptor phosphorylation, which are also modulated by pharmacological intervention. In summary, while GR-related changes after CMS might be relevant for the depressive phenotype, the ability of antidepressant treatment to correct some of these alterations may contribute to the normalization of HPA axis dysfunctions associated with stress-related disorders.Neuropsychopharmacology advance online publication, 21 November 2012; doi:10.1038/npp.2012.225.
HubMed – depression

 


 

Depression treatment, better than any medication! – Here’s something I couldn’t see without laughing. 🙂

 

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