Neuroscience
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This study aims to explore the relationship between the cerebral microbleeds (CMBs) and white matter structural network in patients with white matter hyperintensities (WMHs), and the correlation with the cognitive impairment. ⋯ In this study, patients with a high count (≥5) of CMBs or DI-CMBs are associated with disruptions in the microstructure of the white matter structural network, partially impacting the visual network of occipital lobe and affecting the cognitive function of information processing speed and attention.
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Cartwheel (CW) neurons are glycinergic interneurons in the dorsal cochlear nucleus (DCN) that exhibit spontaneous firing, resulting in potent tonic inhibition of fusiform neurons. CW neurons expressing open ATP-sensitive potassium (KATP) channels do not fire spontaneously, and activation of KATP channels halts spontaneous firing in these neurons. However, the conditions that regulate KATP channel opening in CW neurons remain unknown. ⋯ We hypothesized that intense membrane ion ATPase activity during strong depolarization would deplete intracellular ATP, leading to KATP channel opening. Consistent with this, depolarizing CW neurons with a 250 pA DC did not increase spontaneous firing because the depolarization activated KATP channels; however, the same depolarization after tolbutamide administration increased firing, suggesting that ATP depletion triggered KATP channel opening to limit action potential firing. These results indicate that KATP channels in the DCN provide dynamic control over action potential firing, preventing excessive excitation during high-firing activity.
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Reaching movements are essential for daily tasks and they have been widely investigated through kinematic, kinetic, and electromyographic (EMG) analyses. Recent studies have suggested that the central nervous system simplifies control of reaching movements by using muscle synergies. An alternative approach is to investigate how EMG activity reflects at theneural level with the representation of spinal maps that visualize the spatiotemporal activity of motoneuronal pools. ⋯ The multidimensional Pearson's correlation coefficient was used to assess thesimilarity of spinal maps among repetitions of movements within subjects (intra-subject variability) and among participants (inter-subject variability). Spinal maps of tonic and total EMG showed high intra- and inter-subject similarity in all planes, while phasic spinal maps were less repeatable and more subject-specific. These results may be useful as areference for rehabilitation, clinical, and neurological evaluations, especially for longitudinal assessments.
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SH-SY5Y human neuroblastoma cells have been extensively used as an in vitro model system in a diverse range of studies involving neurodevelopment, neurotoxicity, neurodegeneration, and neuronal ageing. Both naïve and differentiated phenotypes of SH-SY5Y cells are utilized to model human neurons under in vitro conditions. The process of differentiation causes extensive remodeling of neuronal cells at multiple omic levels, including the epigenome and proteome. ⋯ Proteins identified in arsenic-treated differentiated SH-SY5Y cells were more enriched in pathways underlying multifactorial neurotoxic events. Additionally, more functional regulatory modules have been identified between the miRNAs and proteins differentially expressed in arsenic-treated differentiated SH-SY5Y cells relative to naïve cells. Collectively, our studies have shown that differentiated SH-SY5Y cells displayed alterations in the expression of a greater number of miRNAs and proteins following neurotoxicant exposure, indicating their higher responsivity.
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Transparency of Caenorhabditis elegans enables microscopic in vivo imaging of cellular processes, but immobilization is required due to high locomotor activity. Here, anesthetic-like effects of dissociate anesthetic ketamine in adult C. elegans are presented using video recordings and infrared-based automated activity tracking. Ketamine caused a reversible blockade of locomotion at a similar concentration (20-50 mM) at which conventionally used immobilizing agent sodium azide (NaN3) produces paralysis. ⋯ However, a marked chemosensation deficiency was noted immediately after 20 mM ketamine exposure. Short-term ketamine treatment did not show signs of SKN-1 (skinhead-1) activation, a marker of the stress response associated with NaN3. In sum, our results show ketamine's potential as a non-toxic nematode immobilizing agent and rationalize C. elegans as a model organism to understand its pharmacology.