Neuroscience
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Numerous studies have indicated dental pulp stem cells (DPSCs) potency to differentiate into several types of cell lineages. Oligodendrocyte lineage transcription factor 2 (OLIG2) plays an important role in the oligodendrogenic pathway. In this study, a tetracycline (Tet)-inducible system expressing OLIG2 gene was transfected into human DPSCs to direct their differentiation toward oligodendrocyte progenitor cells (OPCs). ⋯ Improvement of behavioral symptoms was efficiently observed from the second week to the sixth week post-transplantation. Our findings showed that exogenous expression of the OLIG2 gene by a Tet-regulated system could be used as an efficient way to induce the differentiation of DPSCs into functional oligodendrocytes. Meanwhile, the DPSC-derived OPCs have relevant therapeutic potential in the animal model of sciatic nerve injury and therefore might represent a valuable tool for stem cell-based therapy in inflammatory and degenerative diseases of the peripheral and central nervous systems (CNSs).
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Numerous clinical investigations have reported that children with cerebral palsy (CP) have tactile discrimination deficits that likely limit their ability to plan and manipulate objects. Despite this clinical awareness, we still have a substantial knowledge gap in our understanding of the neurological basis for these tactile discrimination deficits. Previously, we have shown that children with CP have aberrant theta-alpha (4-14 Hz) oscillations in the somatosensory cortices following tactile stimulation of the foot. ⋯ This inference is plausible since the participating children with CP had Manual Ability Classification System (MACS) levels between I and II. In contrast to the theta-alpha results, children with CP did exhibit a sharp increase in beta activity during the same time period, which was not observed in TD children. This suggests that children with CP still have deficits in the computational aspect of somatosensory processing.
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The neural basis of human speech is unclear. Intracranial electrophysiological recordings have revealed that high-gamma band oscillations (70-150Hz) are observed in the frontal lobe during speech production and in the temporal lobe during speech perception. Here, we tested the hypothesis that the frontal and temporal brain regions had high-gamma coherence during speech. ⋯ First, we observed high-gamma band as well as theta (4-8Hz) coherence between frontal and temporal lobes. Second, both high-gamma and theta coherence were stronger when subjects were actively vocalizing as compared to playback of the same vocalizations. These findings provide evidence that coupling between sensory-motor networks measured by high-gamma coherence plays a key role in feedback-based monitoring and control of vocal output for human vocalization.
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Rapid automatized naming (RAN) has been established to be a strong predictor of reading. Yet, the neural correlates underlying the RAN-reading relationship remain unknown. Thus, the purpose of this study was to determine: (a) the extent to which RAN and reading activate similar brain regions (within subjects), (b) whether RAN and reading are directly related in the shared activity network outlined in (a), and (c) to what extent RAN neural activation predicts behavioral reading performance. ⋯ Further, we found a unique relationship between in-scanner reading response time and RAN PSC in the left inferior frontal gyrus. Taken together, these findings support the notion that RAN and reading activate similar neural networks. However, the relationship between RAN and reading is primarily driven by commonalities in the motor-sequencing/articulatory processes.
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The neural substrates of fatigue induced by muscular activity have been addressed in depth in relation to isometric tasks. For these activities, when fatigue develops, it has been noted that the duration of the silent periods (SPs) increases in response to both transcranial magnetic stimulation (TMS) of primary motor cortex or electric cervicomedullary stimulation (CMS). However, fatigue is known to be task-dependent and the mechanisms giving rise to a decrease in motor performance during brief, fast repetitive tasks have been less studied. ⋯ They increased TMS-SPs, but not CMS-SPs. On the other hand, isometric contraction had a clear impact on spinal circuits. The consideration of these differences might help to optimize the study of fatigue in physiological conditions and neurological disorders.