Neuroscience
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Anxiety is considered an important protracted abstinence symptom that can aggravate craving and relapse risk in opioid addicts. Although the insular cortex (IC) has been reported to be a key brain region in mediating emotional and motivational alterations induced by drug consumption and withdrawal, the role of IC in anxiety related to protracted abstinence remains elusive. ⋯ Bilateral lesion of the medial IC, but not the anterior or posterior IC with ibotenic acid (IBO) alleviated the anxiety-like behavior. (3) Expression of Wnt7a in the medial IC was significantly increased after 28 days of withdrawal, and specific down-regulation of Wnt7a with AAV-shWnt7a also alleviated the anxiety-like behavior. The findings reveal the medial IC is involved in mediating anxiety-like behavior related to morphine protracted abstinence, in which Wnt7a plays a critical role.
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The perirhinal cortex (PRH) is considered a crucial cortical area for familiarity memory and electrophysiological studies have reported the presence of visual familiarity encoding neurons in PRH. However, recent evidence has questioned the existence of these neurons. ⋯ However, the PRH showed no response modulation with respect to familiarity under a variety of different conditions or retention delays. These results indicate that the PRH does not contribute to familiarity/novelty encoding using passively exposed visual stimuli.
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Alzheimer's disease (AD) is a progressive neurodegenerative disorder, with no effective method for its treatment so far. The pathogenesis of AD has been reported, but the endogenous metabolic profile and disease-related biomarkers are still not clear. To better understand AD, an AD model induced by injecting β-amyloid 25-35 (Aβ 25-35) solution into bilateral hippocampus was developed on Sprague-Dawley rats. ⋯ The results showed that compared with healthy control rats, AD rats suffered from cognitive dysfunction, hippocampus damage, Aβ formation and tau phosphorylation at 8 weeks after surgery, suggesting that the Aβ25-35-induced AD model was successfully established. In addition, the levels of γ-aminobutyric acid, acetylcholine, glycine, norepinephrine, serotonin, taurine and dopamine decreased and glutamate and aspartic acid increased in hippocampal tissue of AD rats. 45 altered metabolites mainly involved in 8 metabolic pathways were identified as the endogenous biomarkers of AD. According to the analysis of the biological significance of metabolic profiles, the pathogenesis of AD was mainly due to gut microbiome dysbiosis, inhibition of energy metabolism, oxidative stress injury and loss of neuronal protective substances.
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Stimulation of the mu-opioid receptor (MOR) on nociceptors with fentanyl can produce hyperalgesia (opioid-induced hyperalgesia, OIH) and hyperalgesic priming, a model of transition to chronic pain. We investigated if local and systemic administration of biased MOR agonists (PZM21 and TRV130 [oliceridine]), which preferentially activate G-protein over β-arrestin translocation, and have been reported to minimize some opioid side effects, also produces OIH and priming. Injected intradermally (100 ng), both biased agonists induced mechanical hyperalgesia and, when injected at the same site, 5 days later, prostaglandin E2 (PGE2) produced prolonged hyperalgesia (priming). ⋯ Hyperalgesia, analgesia and priming induced by systemic administration of PZM21 were also prevented by MOR AS-ODN. And, priming induced by systemic PZM21 was also not reversed by intradermal cordycepin or the combination of Src and MAPK inhibitors. Thus, maintenance of priming induced by biased MOR agonists, in the peripheral terminal of nociceptors, has a novel mechanism.
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Audiovisual cuts involve spatial, temporal, and action narrative leaps. They can even change the meaning of the narrative through film editing. Many cuts are not consciously perceived, others are, just as we perceive or not the changes in real events. ⋯ This was reflected by differences in the theta rhythm between 200 and 400 ms, in visual and frontal zones, and can be connected to the different demands that each style of edition makes on working memory and conscious processing after cutting. Also, at the time of cuts, the causality between visual, somatosensory, and frontal networks is altered in any editing style. Our findings suggest that cuts affect media perception and chaotic and fast audiovisuals increase attentional scope but decrease conscious processing.