Neuroscience
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Microglia polarization plays a crucial role in inflammatory injury of brain following intracerebral hemorrhage (ICH). Heme oxygenase-1 (HO-1) has demonstrated protective properties against inflammation and promote hematoma clearance after ICH. The objective of this study was to explore impacts of HO-1 on microglia polarization and phagocytosis after ICH, along with the underlying mechanism. ⋯ Therefore, our data demonstrated that HO-1 alleviated nerve injury and induced M2 polarization and phagocytosis of microglia after ICH via inhibiting NF-κB signaling pathway, which could provide deepen the pathological understanding of ICH and provide potential intervention targets and drug candidate for ICH.
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Corticotropin-releasing factor (CRF) is an important stress hormone, and because of the different distributions and functions of its receptors, CRF has various effects on the stress response of animals. CRF receptor 2 (CRFR2) is a functional receptor of CRF that may be related to appetite regulation and sex differences. In this study, male and female C57BL/6 mice were exposed to an ambient temperature of 4 °C, and feed intake were determined. ⋯ As a result, 1) there were only significant changes in 2 h feed intake and rectal temperature in males; 2) neuronal excitability was elevated in the paraventricular thalamus (PVT) and paraventricular hypothalamic nucleus (PVH) brain regions of both male and female mice; 3) serum corticosterone and the expression of corticosterone receptors in the PVH were elevated in males but not in females; 4) the activation of the CRFR2 signal in the PVT and PVH brain regions differed by sex: the expression of CRFR2 was upregulated in male mice, and the phosphorylation of protein kinase B (AKT) and cAMP-response element binding protein (CREB) was significantly reduced; and 5) the cold-evoked eating behavior of male mice was abolished when CRFR2 in the PVT was knocked down. In summary, we conclude that male mice are more sensitive to cold stress than are female mice. The CRFR2/AKT/CREB signaling pathway in the PVT and PVH may mediate sex differences in the eating behavior of cold-exposed mice.
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Prepulse inhibition (PPI) refers to the phenomenon in which a weak sensory stimulus before a strong one significantly reduces the startle reflex caused by the strong stimulus. Perceptual spatial separation, a phenomenon where auditory cues from the prepulse and background noise are distinguished in space, has been shown to enhance PPI. This study aims to investigate the neural modulation mechanisms of PPI by the spatial separation between the prepulse stimulus and background noise, particularly in the deep superior colliculus (deepSC). ⋯ The prepulse stimulus was a segment of narrowband noise, with interaural time differences adjusted so that the prepulse stimulus and background noise were perceived as either ipsilaterally leading or contralaterally leading, resulting in perceptual spatial fusion or spatial separation. The results showed that under conditions of spatial separation, the stimulus-response coherence of the envelope and fine structure components of the prepulse stimulus in the deepSC was significantly enhanced, the response of the deepSC to the stimulus was significantly reduced in the presence of the prepulse stimulus, and the envelope component of the prepulse stimulus was positively correlated with the inhibitory effect. The above results suggest that perceptual spatial dissociation can significantly enhance the expression of deepSC, particularly the precision of the envelope component, thereby significantly affecting the electrophysiological response of PPI.
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This study explored surface brain morphometry in type 1 diabetes including focus on painful diabetic peripheral neuropathy (DPN). Brain MRI was obtained from 56 individuals with diabetes (18 without DPN, 19 with painless DPN, 19 with painful DPN) and 20 healthy controls. Cortical thickness, sulcus depth, and gyrification were analysed globally and regionally in each group and in the combined diabetes group. ⋯ Cortical thinning manifested across the brain cortex in diabetes, especially for painful DPN. Altered postcentral gyrus morphometry may be associated with neuropathic pain. Assessing cortical morphometry may be critical for comprehending central neuropathy and the manifestation of painful DPN in diabetes.
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The optimal stimulation frequency for inducing neuromodulatory effects remains unclear. The purpose of our study was to investigate the effect of neuromuscular electrical stimulation (NMES) with different frequencies on cortical and spinal excitability. Thirteen able-bodied individuals participated in the experiment involving NMES: (i) low-frequency at 25 Hz, (ii) high-frequency at 100 Hz, and (iii) mixed-frequency at 25 and 100 Hz switched every one second. ⋯ Our results showed that mixed frequency was most effective in modulating corticospinal excitability, although motor performance was not affected by any intervention. The cortical silent period was prolonged and Mmax was inhibited by all frequencies, while the F-wave and MVC were unaffected. Mixed-frequency stimulation could recruit a more diverse range of motor units, which are recruited in a stimulus frequency-specific manner, than single-frequency stimulation, and thus may have affected corticospinal facilitation.