Neuroscience
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Exposure to violence during childhood can lead to functional changes in brain regions that are important for emotion expression and regulation, which may increase susceptibility to internalizing disorders in adulthood. Specifically, childhood violence exposure can disrupt the functional connectivity among brain regions that include the prefrontal cortex (PFC), hippocampus, and amygdala. Together, these regions are important for modulating autonomic responses to stress. ⋯ Heart rate and SCL were recorded during each scan. Post-stress heart rate varied negatively with post-stress amygdala-inferior parietal lobule rsFC and positively with post-stress hippocampus-anterior cingulate cortex rsFC among those exposed to high, but not low, levels of violence. Results from the present study suggest that post-stress fronto-limbic and parieto-limbic rsFC modulates heart rate and may underlie differences in the stress response among those exposed to high levels of violence.
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There is growing basic and clinical evidence that major depressive disorder (MDD) is associated with gut microbiome alterations, but clinical studies have tended not to adjust for confounding factors. And few studies on the gut microbiome focused on young adults with MDD. Here we performed a pilot study to compare the gut microbiome of young adults with MDD with healthy controls. ⋯ Abundance of Sutterellaceae and species belonging to Clostridium, Eubacterium, and Ruminococcus were significantly different between groups. The cysteine degradation I pathway was increased in MDD. After controlling for most confounding factors, this pilot study provides new evidence on the specific, often subtle gut dysbiosis affecting young adults with depression.
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The nonapeptide system modulates a diversity of social behaviors, including aggression, parental care, affiliation, sexual behavior, and pair bonding. Such social behaviors are regulated through oxytocin and vasopressin activation of the oxytocin receptor (OXTR) and vasopressin V1a receptor (AVPR1A) in the brain. Nonapeptide receptor distributions have been mapped for several species, however, studies have demonstrated that there is substantial variation across species. ⋯ Here we conducted receptor autoradiography to map distributions of OXTR and AVPR1A binding throughout the basal forebrain and midbrain of female and male Mongolian gerbils. Further, we assessed whether gonadal sex influenced binding densities in brain regions important for social behavior and reward, however, we observed no effects of sex on OXTR or AVPR1A binding densities. These findings provide mapping distributions of nonapeptide receptors in male and female Mongolian gerbils, laying a foundation for future studies that seek to manipulate the nonapeptide system to examine nonapeptide-mediated social behavior.
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Perinatal hypoxic-ischemic (HI) brain injury leads to mortality and morbidity in neonates and children. There are no effective and practical methods to attenuate this brain injury. This study determined whether desflurane, a volatile anesthetic with limited effect on the cardiovascular system, protected against HI-induced brain damage and the role of transient receptor potential ankyrin 1 (TRPA1), a mediator for simulated ischemia-induced myelin damage, in this protection. ⋯ However, the combination of TRPA1 inhibition and desflurane post-treatment did not preserve brain tissues, learning and memory better than TRPA1 inhibition or desflurane post-treatment alone. Our results suggest that desflurane post-treatment induces neuroprotection against neonatal HI. This effect may be mediated by inhibiting TRPA1.
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Previous studies have shown that in addition to its role within the voltage-gated calcium channel complex in the plasma membrane, the neuronal CaVβ subunit can translocate to the cell nucleus. However, little is known regarding the role this protein could play in the nucleus, nor the molecular mechanism used by CaVβ to enter this cell compartment. This report shows evidence that CaVβ3 has nuclear localization signals (NLS) that are not functional, suggesting that the protein does not use a classical nuclear import pathway. ⋯ Likewise, through proximity ligation assays (PLA), it was found that members of the heterogeneous nuclear ribonucleoproteins (hnRNPs) and B56δ, a regulatory subunit of the protein phosphatase 2A (PP2A), could function as proteins that regulate this piggyback mechanism. On the other hand, bioinformatics and site-directed mutagenesis assays allowed the identification of a functional nuclear export signal (NES) that controls the exit of CaVβ3 from the nucleus, which would allow the completion of the nuclear transport cycle of the protein. These results reveal a novel mechanism for the nuclear transport cycle of the neuronal CaVβ3 subunit.