Neuroscience
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Emotions rely on bodily states, and perceiving the emotions of others depends on awareness of one's own emotional state. However, the intercorrelations among interoception, alexithymia, and empathy are not well understood, and the neural mechanisms behind this connection are also largely unknown. To address these issues, 297 college students participated in this study, completing measures of interoceptive sensibility (IS), empathy and alexithymia and undergoing resting-state fMRI scans. ⋯ Furthermore, right BLA-left precuneus connectivity was found to mediate the impact of interoception on cognitive empathy. In conclusion, this study provides valuable insights into the relationships among IS, alexithymia, and empathy. The right BLA-left precuneus connectivity may serve as a shared neural substrate between interoception and cognitive empathy.
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Psilocybin has received attention as a treatment for depression, stress disorders and drug and alcohol addiction. To help determine the mechanisms underlying its therapeutic effects, here we examined acute effects of a range of behaviourally relevant psilocybin doses (0.1-3 mg/kg SC) on regional expression of Fos, the protein product of the immediate early gene, c-fos in brain areas involved in stress, reward and motivation in male rats. We also determined the cellular phenotypes activated by psilocybin, in a co-labeling analysis with NeuN, a marker of mature neurons, or Olig1, a marker of oligodendrocytes. ⋯ These results extend previous research by determining Fos expression in multiple brain areas at a wider psilocybin dose range, and the cellular phenotypes expressing Fos. The data also highlight the amygdala, especially the central nucleus, a key brain region involved in emotional processing and learning and interconnected with other brain areas involved in stress, reward and addiction, as a potentially important locus for the therapeutic effects of psilocybin. Overall, the present findings suggest that the central amygdala may be an important site through which the initial brain activation induced by psilocybin is translated into neuroplastic changes, locally and in other regions that underlie its extended therapeutic effects.
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Virgin and pups-naïve female and male adult mice display two opposite responses when they are exposed to pups for the first time. While females generally take care of the pups, males attack them. Since the nucleus accumbens (NA), and its dopaminergic modulation, is critical in integrating information and processing reward and aversion, we investigated if NMDA- and 6-OHDA-induced lesions, damaging mostly NA output and dopaminergic inputs respectively, affected female maternal behavior (MB) or male infanticidal behavior (IB) in mice. ⋯ The current study shows that an intact NA is not necessary for the expression of MB and IB. However, dopaminergic inputs to NA play different role in MB and IB. While damaging dopaminergic terminals into the NA did not affect IB, it clearly delayed the more flexible and rewarding expression of parental behavior.
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There is increasing evidence that major trauma can adversely affect the brain and cognition. In some cases, trauma may lead to deficits in executive function (EF). The anterior insula may be a causal outflow hub acting to coordinate EF-related brain networks. ⋯ No correlation was found between abnormal connectivity and cognitive/post-traumatic stress symptoms in participants with EFD. These results suggest that excessive connections between the insula and DMN could contribute to EFD after trauma. Overall, this study provides novel references into the neural mechanisms of EF status after trauma exposure.
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ECHDC3 is a risk gene for white matter (WM) hyperintensity and is associated with insulin resistance. This study aimed to investigate whether ECHDC3 variants selectively regulate brain WM microstructures and episodic memory in patients with type 2 diabetes mellitus (T2DM). We enrolled 106 patients with T2DM and 111 healthy controls. ⋯ We observed a noteworthy interaction between genotype and diagnosis on FA in the right inferior temporal WM, right anterior limb of the internal capsule, right frontal WM, and the right hippocampus. Modulated mediation analysis revealed a significant ECHDC3 modulation on the T2DM → right hippocampal FA → short-term memory pathway, with only rs11257311 G risk homozygote demonstrating significant mediation effect. Together, our findings provide evidence of ECHDC3 modulating the effect of T2DM on right hippocampal microstructural impairment and short-term memory decline, which might be a neuro-mechanism for T2DM related episodic memory impairment.