Neuroscience
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Paced Auditory Serial-Addition Task (PASAT) is a complex task commonly used to examine patients with diffuse brain damage. A visual version of the neuropsychological test (Paced Visual Serial-Addition Task, PVSAT) has also been introduced to clinical practice, and both versions were adapted to be used in neuroimaging, namely functional magnetic resonance imaging (fMRI). The aim of our work was direct comparison of auditory and visual versions of the paced serial addition test (PASAT/PVSAT) in a within-subject and within-session study and description of the commonalities and differences in both activated and deactivated brain regions. ⋯ Activation in one task and deactivation in the other jointly contributed to significant differences in all occipital and occipitotemporal regions. Both tasks activated right FEF, but activation during PASAT was significantly stronger than during PVSAT. Between-modality differences should be considered when preparing and interpreting neuroimaging experiments.
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Humans have been consistently shown to be bad at making decisions, especially in disadvantageous situations. In this study, we designed a task that simulates real-life non-strategic gambling to examine the effect of win-lose balance situations (WIN, LOSS, TIE) on decision-making. In behavioral performances, participants showed shorter response time (RT) in LOSS than in WIN and TIE conditions. ⋯ Positive correlation was found between brain activation in IFG and RT in LOSS. Overall, we concluded that, in disadvantageous conditions, participants are frustrated by their negative results and tend to make a random selection without full consideration. In advantageous conditions, participants' motivations to gamble are elicited and they tend to engage in more endeavors in making decisions.
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Type A behavior pattern (TABP) is characterized by competitiveness and hostility, time urgency and impatience. These traits can have a significant impact on physical and mental health. We have not found studies focusing on brain structure or functional connectivity correlates associated with individual differences in TABP. ⋯ In addition, TABP was positively correlated with the strength of rsFC between the left ventral striatum and areas in the left ventromedial prefrontal cortex (vmPFC) and the right rostral anterior cingulate cortex (rACC). These regions are associated with achievement striving related to impatience, aggressiveness, and worry under time pressure. In summary, the combination of morphometric results (increased rGMV of the left sgACC) and functional connectivity findings (increased rsFC between the left ventral caudate and the left vmPFC/right rACC in the fronto-striatal network) may provide a valuable basis for a comprehensive understanding of the neural circuitry underlying individual differences in TABP.
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Mutation of TAR DNA-binding protein-43 (TDP-43) is detected in familial and sporadic amyotrophic lateral sclerosis (FALS and SALS). TDP-43-positive cytoplasmic inclusions are present in both neuron and glia of ALS, although not in mutant Cu/Zn-superoxide dismutase (mSOD1)-related or RNA binding protein Fused in sarcoma (FUS)-related ALS. Previous studies have established that cortical hyper-excitability is common to both FALS and SALS patients. ⋯ Other studies suggest that Nav channel activity can be increased directly by different oxidative species and, we have shown previously that oxidative stress and mitochondrial dysfunction occurs simultaneously in the cellular model of mutant TDP-43 and can be ameliorated by dimethoxy curcumin (DMC), a safe and effective antioxidant. In the present study we found that the abnormities of APs and Nav channels were significantly ameliorated when treated with DMC (15μM) for 24h, suggesting a dropping-excitability state. Taken together, mutant Q331K TDP-43 induces high excitability in a motoneuron-like cellular model, and this abnormal state is rescued by DMC which may act through alleviation of oxidative stress and mitochondrial dysfunction.
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Glutamate transporter type 3 (EAAT3) may play a role in cognition. Isoflurane enhances EAAT3 trafficking to the plasma membrane. Thus, we used isoflurane to determine how EAAT3 might regulate learning and memory and the trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, such as GluR1, to the plasma membrane, a fundamental biochemical process for learning and memory. ⋯ Finally, isoflurane inhibited context-related fear conditioning in EAAT3(-/-) mice but not in wild-type mice. Thus, isoflurane may increase GluR1 trafficking to the plasma membrane via EAAT3 and inhibit GluR1 trafficking via protein phosphatase. Lack of EAAT3 effects leads to decreased GluR1 trafficking and impaired cognition after isoflurane exposure in EAAT3(-/-) mice.