Neuroscience
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Previous studies have established the importance of the fronto-parietal brain network in the information processing of reasoning. At the level of cortical source analysis, this eletroencepalogram (EEG) study investigates the functional reorganization of the theta-band (4-8Hz) neurocognitive network of mathematically gifted adolescents during deductive reasoning. ⋯ Further correlation analyses have shown that the enhanced workspace configuration with respect to the global topological metrics of the theta network in math-gifted subjects is correlated with the intensive frontal midline theta (fm theta) response that is related to strong neural effort for cognitive events. These results suggest that by investing more cognitive resources math-gifted adolescents temporally mobilize an enhanced task-related global neuronal workspace, which is manifested as a highly integrated fronto-parietal information processing network during the reasoning process.
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We tested predictions of a hierarchical scheme on the control of natural movements with referent body configurations. Subjects occupied an initial hand position against a bias force generated by a HapticMaster robot. A smooth force perturbation was applied to the hand consisting of an increase in the bias force, keeping it at a new level for 5s, and decreasing it back to the bias value. ⋯ We interpret unintentional movements as consequences of back-coupling between the actual and referent configurations at the task level. The results suggested that both intentional and unintentional movements resulted from shifts of the body referent configuration produced intentionally or as a result of the hypothesized back-coupling. Inter-trial variance signature reflects similar task-specific stability properties of the system following both types of movements, intentional and unintentional.
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To evaluate physiological roles of the large, second cytoplasmic loops (C2) situated between the M3 and M4 transmembrane domains of nicotinic acetylcholine receptor (nAChR) subunits. We have constructed chimeric β2 (β2χ) and β4 (β4χ) subunits in which the "nested" C2 domains (but not the "proximal" sequences of ∼14 residues immediately adjacent to the M3 or M4 domains) of these β subunits were replaced by the corresponding sequence from the serotonin 5-HT3A receptor subunit. We previously reported that heterologously expressed nAChR containing α4 and β2χ subunits displayed a faster whole-cell current decay in its agonist response compared to responses of all-wild-type α4β2-nAChR. ⋯ In addition, cell-attached, single-channel recording shows that both acetylcholine-activated α4β2χ- and α4β4χ-nAChR have a significantly lower mean open probability, shorter mean open-time, and a longer mean closed-time than their fully wild-type counterparts while not having different conductance amplitudes. These findings reveal microscopic bases for the faster desensitization of α4(∗)-nAChR containing chimeric instead of wild-type β subunits. Our findings also remain consistent with novel and unexpected roles of β subunit-nested C2 domains in modulation of α4(∗)-nAChR function.
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Motor feedback usually engages distinct sensory and cognitive processes based on different feedback conditions, e.g., the real and sham feedbacks. It was thought that these processes may rely on the functional connectivity among the brain networks. However, it remains unclear whether there is a difference in the network connectivity between the two feedback conditions. ⋯ Using independent component analysis and functional connectivity analysis, we found that as compared with the sham feedback, the real feedback recruited stronger negative connectivity between the executive network (EN) and the posterior default mode network (pDMN). More intriguingly, the left frontal parietal network (lFPN) exhibits positive connectivity with the pDMN in the real feedback while in the sham feedback, the lFPN shows connectivity with the EN. These results suggest that the connectivity among EN, pDMN, lFPN could differ depending on the real and sham feedbacks, and the lFPN may balance the competition between the pDMN and EN, thus supporting the sensory and cognitive processes of the motor feedback.
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Tastes and odors influence the perception of a meal. Especially food aromas can act as potent signals to modulate our eating behavior with strong dependency on the reward produced by food. In this investigation we aimed to study the electrophysiological response to food- and non-food-related odors in healthy volunteers. Analyses revealed specific scalp potential maps for the two conditions; in particular the source of the map in the "food" condition seemed to be associated with the processing of rewards; the specific map in the "non-food" condition reflects odor characteristics excluding the reward.