Neuroscience
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The limbic system has a central role for the integration of several cognitive and visceral functions through an extended network of connections involving the hippocampus and the amygdala. A number of studies performed in humans have been dedicated to the investigation of supratentorial limbic pathways by means of non-invasive MRI approaches, such as DTI. However, detection of possible limbic connections involving the brainstem and the spinal cord is still missing. ⋯ Quantitative evaluation of diffusion parameters was also performed. Findings of the present study are in agreement with the literature and provide the first report of possible limbic connections between the brainstem and the spinal cord in human brain. Since these pathways might also have important implications both in physiological and pathological contexts, further studies should be conducted in order to confirm our data as well as to define functional features of these brain connections.
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Practicing sport at top level requires excellent physical and cognitive skills. The goal of the present study was to investigate whether specific sport practice may affect the preparation-perception-action stages of processing during a visuo-motor task requiring perceptual discrimination and fast response. We recruited 39 participants (two groups of professional fencers and boxers, and a control group; N=13 for each group) and measured behavioral performance and event-related potentials (ERPs) while performing a go/no-go task. ⋯ Combat sports require fast action execution, but the preparatory brain activity might differ according to the specific practice required by each discipline. Boxers might afford to commit more errors (as reflected by high commission error (CE) rate and by a small pN amplitude), while fencers have to be as much fast and accurate as possible (thanks to an enhanced pN amplitude). Although the possible influence of repetitive head blows on cerebral activity cannot be excluded in boxers, our results suggest that cognitive benefits of high-level sport practice might also be transferred to the daily (i.e., no sport-related) activities.
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Inference on nociceptive and pain-related processes from functional magnetic resonance imaging is made with the assumption that the coupling of neuronal activity and cerebral hemodynamic changes is stable. However, since nociceptive stimulation is associated with increases in systemic arterial pressure, it is essential to determine whether this coupling remains the same during different levels of nociception and pain. The main objective of the present study was to compare the amplitude of local field potentials (LFP) and cerebral blood flow (CBF) changes in the primary somatosensory cortex during nociceptive electrical stimulation of the contralateral or ipsilateral forepaw in isoflurane-anesthetized rats, while manipulating mean arterial pressure (MAP). ⋯ Thus, neurovascular coupling was altered differently by stimulus-induced MAP changes, depending on stimulus intensity and location. This demonstrates that CBF changes evoked by nociceptive processing do not always match neuronal activity, which may lead to inaccurate estimation of neuronal activity from hemodynamic changes. These results have important implications for neuroimaging of nociceptive and pain-related processes.
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We compared the efficacy of a modified truncated 24-aa peptide (TFP5), derived from the cyclin-dependent kinase 5 (CDK5)-activating cofactor p35, with mild hypothermia (MH), and determined whether the efficacy of TFP5 is affected by MH. ⋯ TFP5 is comparable to MH in improving neurological outcomes in early-stage adult ischemic stroke. When TFP5 is given along with MH, less neurological deficit tends to be achieved.
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Decreased proteolytic clearance of soluble amyloid β (Aβ) in microglia affects Aβ accumulation on Alzheimer's disease progression. However, the potential molecular mechanism by which microglial Aβ uptake is regulated remains unclear. In this study, we identified a microRNA, miR-124, that was down-regulated in aging with a function in regulating apolipoprotein E (ApoE)-dependent Aβ uptake by targeting regulatory factor X1 (RFX1) transcripts on BV2 microglia cell. ⋯ We also identified a miR-124 binding site in the 3'-UTR of RFX1 mRNA and a RFX1 binding site in the first intron of ApoE gene. Furthermore, interfering this signaling pathway by knocking down RFX1 significantly improved Aβ uptake in BV2 cells. These data demonstrate the mechanism through which decreased miR-124 expression under oxidative stress slowed Aβ uptake and suggest that RFX1 might be a target for improving Aβ clearance during aging.