Neuroscience
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Prenatal glucocorticoids (GCs) are routinely used for pregnant women in preterm labor to prevent respiratory distress syndrome and intraventricular hemorrhage in premature infants. However, the effect of antenatal GCs on neurogenesis in preterm neonates remains elusive. Herein, we hypothesized that prenatal GCs might suppress both glutamatergic and GABAergic neurogenesis in preterm rabbits and that this treatment would induce distinct changes in the expression of transcription factors regulating these developmental events. ⋯ Moreover, the mRNA expression of transcription factors, including Pax6, Ngn1/2, Emx1/2, Insm1, Dlx1, Nkx2.1, and Gsh2, were comparable between the two groups. However, there was a transient elevation in Mash1 protein in betamethasone-treated pups relative to controls at birth. These data suggest that prenatal GC treatment does not significantly impact the balance of glutamatergic and GABAergic neurogenesis in premature infants.
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High-density, event-related brain potentials (ERPs) were recorded to explore differences in spatiotemporal dynamics between modus ponens (MP) and modus tollens (MT) in the Wason selection task. Results showed that MP elicits a more positive P3b-like component than MT from 400 to 800 ms. ⋯ This result suggests that MT occupies more cognitive resources than MP in the final stages of proposition testing. The short and small left frontal LNC obtained by MP implies examination of the expectable conclusion, whereas the long and large left frontal LNC elicited by MT may be involved in the retention operation of the card in working memory from the monitoring and inspecting putative conclusion in the later stages of proposition testing.
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Previous studies on the neural basis of insight reflected weak consistency except for the anterior cingulate cortex. The present work adopted the semantic and homophonic punny riddle to explore the uniformity and nonuniformity of neural activities correlated to different insight problem solving. ⋯ However, during -400 to 0 ms before the riddles were solved, the semantic punny riddles induced a positive event-related potential (ERP) deflection over the temporal cortex for retrieving the extensive semantic information, while the homophonic punny riddles induced a positive ERP deflection over the temporal cortex and a negative one in the left frontal cortex which might reflect the semantic and phonological information processing respectively. Our study indicated that different insight problem solving should have the same cognitive process of detecting cognitive conflicts, but have different ways to solve the conflicts.
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Neuroglobin (NGB), a protein highly expressed in the retina, has been shown to be up-regulated to protect neurons from hypoxic and ischemic injuries. It exhibits neuroprotective functions and plays an important role in the survival of neurons. Recent studies show that light-emitting diode (LED) white light emitted significant amounts of blue light (short-wavelength), which may be harmful to retinal cells, but the studies about biomarkers for evaluating the damage from LED white light are still insufficient. ⋯ The LED red light (625 nm), green light (527 nm) and blue light (453 nm) increased the expression of NGB and caused TdT-mediated dUTP nick-end labeling-positive cells, especially in the blue-light group. In addition, a negative correlation between NGB and rhodopsin was observed. These findings suggested that there was a correlation between NGB expression and the severity of the retinal damage, indicating NGB's potential function as a biological marker of retinal damage induced by LED light.
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Environmental enrichment can modulate mild and chronic stress, responses to anxiogenic stimuli as well as drug vulnerability in a number of animal models. The current study was designed to examine the impact of postnatal environmental enrichment on selectively bred 4th generation high- (HAn) and low-anxiety (LAn) male rats. After weaning, animals were placed in isolated (IE), social (SE) and enriched environments (EE) (e.g., toys, wheels, ropes, changed weekly). ⋯ In the physiological tests, animals housed in EE showed elevated adrenocortical responses to forced novel object exposure but decreased body temperature and blood pressure changes after an air puff stressor. All animals reared in EE and SE had elevated brain-derived neurotrophic factor (BDNF)-positive cells in the central amygdala (CeA), CA1 and CA2 hippocampal regions and the caudate putamen, but these differences were most pronounced in HAn rats for CeA, CA1 and CA2. Overall, these findings suggest that environmental enrichment offers benefits for trait anxiety rats including a reduction in behavioral and physiological responses to anxiogenic stimuli and AMPH sensitivity, and these responses correlate with changes in BDNF expression in the central amygdala, hippocampus and the caudate putamen.