Neuroscience
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Developmental dyscalculia (DD) is characterized by lower numerical and finger-related skills. Studies of enumeration among those DD that suggested core deficiency in pattern recognition, working memory or/and attention were mostly carried out in the visual modality. In our study, we examined visual (dots) enumeration of 1-10 stimuli and tactile (vibration) enumeration of 1-10 fingers among DD and matched-control adults. ⋯ In the tactile task, DD participants showed less accurate tactile enumeration only for neighboring arrangements, more profoundly for finger counting (FC) patterns. The longer exposure time in the visual task enabled us to explore pattern recognition effects when working memory and attention loads were low. We discuss possible modal-independent deficits in pattern recognition and working memory on enumeration performance among those with DD and the unique role of fingers in ordinal and cardinal representation of numbers.
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Trauma to the peripheral nervous system (PNS) results in loss of motor and sensory functions. After an injury, a complex series of events begins, allowing axonal regeneration and target reinnervation. However, this regenerative potential is limited by several factors such as age, distance from the lesion site to the target and severity of lesion. ⋯ In addition, the results of electroneuromyography showed greater amplitude of the compound muscle action potentials in the first and second weeks, suggesting anticipation of regeneration in the inosine group. We also observed in the inosine group, motor and sensory neurons survival, reduction in the number of macrophages and myelin ovoids in the sciatic nerves, and an early recovery of motor and sensory functions. Thus, we conclude that the use of inosine accelerates axonal regeneration promoting an early recovery of motor and sensory functions.
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Sex and ovarian function contribute to hypertension susceptibility, however, the mechanisms are not well understood. Prior studies show that estrogens and neurogenic factors, including hypothalamic glutamatergic NMDA receptor plasticity, play significant roles in rodent hypertension. Here, we investigated the role of sex and ovarian failure on AMPA receptor plasticity in estrogen-sensitive paraventricular nucleus (PVN) neurons in naïve and angiotensin II (AngII) infused male and female mice and female mice at early and late stages of accelerated ovarian failure (AOF). ⋯ Significantly, only late stage-AOF female mice infused with AngII had an increase in GluA1 near the plasma membrane in dendrites of ERβ-expressing PVN neurons. In contrast, prior studies reported that plasmalemmal NMDA GluN1 increased in ERβ-expressing PVN dendrites in males and early, but not late stage AOF females. Together, these findings reveal that early and late stage AOF female mice display unique molecular signatures of long-lasting synaptic strength prior to, and following hypertension.
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Several reports of augmented hyperpolarisation-activated cyclic nucleotide-gated (HCN) currents in seizures have suggested a pro-convulsive identity for HCN channels. The mutations identified in one or more of the four HCN channel subunits are found to be contributing to different epileptic phenotypes. S126L, S632W, V246M and E515K are four different mutations affecting the HCN2 subunit and have been reported in febrile seizures and partial/generalised idiopathic epilepsies. ⋯ Their effects on excitability were studied by observing resting membrane potentials, input resistances and plasticity profiles for measuring the sliding modification threshold (SMT) of Bienenstock-Cooper-Munro (BCM) theory. Virtual knockouts of ion channels other than HCN were also performed to assess their role in altering excitability when they act alongside HCN2 mutations. Our results show that HCN2 mutations can potentially be a primary causative factor for excessive action potential firing through their effect on resting membrane potentials and input resistance.
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Subjective well-being (SWB) is the eternal pursuit of all mankind. Individual differences in SWB may reflect the way of emotional processing. Neuroimaging studies have partly examined the neural mechanism of the individual differences in SWB using resting-state functional magnetic resonance imaging (rs-fMRI). ⋯ Results showed that SWB is positively correlated with the activation of right posterior cingulate cortex, left interior temporal gyrus and left angular gyrus for the comparison of negative stimulus and neutral stimulus, revealing that happy individuals may be more proactive to use attention transfer and behavioral inhibition strategies to decrease negative experiences during negative emotional processing. In addition, high SWB is associated with strong functional connectivity between high-level cognitive networks (e.g., frontal-parietal network) and low-level perceptual networks (e.g., sensorimotor network), and weak functional connectivity within default mode network and within low-level perceptual networks, indicating that the self-reflection, emotional regulation and cognitive control during negative facial emotion processing underlies the individual differences in SWB. These findings provide a novel insight to characterize the brain functional basis of the individual differences in SWB.