Neuroscience
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Sensory disturbance in the orofacial region owing to trigeminal nerve injury is caused by dental treatment or accident. Commercially available therapeutics are ineffective for the treatment of sensory disturbance. Additionally, the therapeutic effects of rapamycin, an allosteric inhibitor of mammalian target of rapamycin (mTOR), which negatively regulates autophagy, on the sensory disturbance are not fully investigated. ⋯ Rapamycin administration facilitated axon regeneration after IANX and increased the number of brain-derived neurotrophic factor positive neurons in the trigeminal ganglion. Thus, recovery from sensory disturbance in the lower lip caused by IANX was markedly facilitated by rapamycin. These findings suggest that rapamycin administration is a promising treatment for the sensory disturbance caused by IANX.
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Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a crucial regulator of neuronal development, neuronal survival, axonal regeneration, and synaptic plasticity. In this study we examined the potential role of PTEN in cognitive function in a mouse model of perioperative neurocognitive disorder (PND). Adult male C57BL/6J mice received intracerebroventricular injections of small interfering RNA (siRNA) against PTEN or control siRNA 3 days prior to exploratory laparotomy (n = 8 per group). ⋯ Surgically treated mice had increased expression of PTEN, AMPK, Bax, IL-1β, and TNF-α, as well as increasing number of activated microglia and apoptosis neurons in the hippocampus. PTEN knockdown significantly attenuated the behavioral deficits in Barnes maze and fear conditioning tests, as well as over-expression of PTEN, AMPK, Bax, IL-1β, and TNF-α induced by surgery. PTEN knockdown could attenuate cognitive deficits induced by trauma, likely through inhibiting the activation of microglia.
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Synucleinopathy disorders are characterized by aggregates of α-synuclein (α-syn), which engage microglia to elicit a neuroinflammatory response. Here, we determined the gene expression and DNA methylation changes in microglia induced by aggregate α-syn. Transgenic murine Thy-1 promoter (mThy1)-Asyn mice overexpressing human α-syn are a model of synucleinopathy. ⋯ Network analysis also showed increased cell mobility and inflammatory functions at 3 months, shifting to cell cycle, immune response, and metabolism changes at 13 months. We observed significant α-syn-induced methylation and gene expression changes in microglia. Our data suggest that α-syn overexpression initiates microglial activation leading to neuroinflammation and cellular metabolic stresses, which is associated with disease progression.
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Spike sorting is an essential step in extracting neuronal discharge patterns which help to decode different activities in the neural system. Therefore, improving the spike sorting accuracy can improve neural decoding performance subsequently. Although many methods are suggested for spike sorting, few studies have evaluated their effect on neural decoding performance. ⋯ In the simulation study, the proposed spike sorting algorithm based on optimized wavelet parameter selection outperformed both the WaveClus spike sorting and traditional PCA-based spike sorting algorithms. The results showed the superiority of the spike sorting algorithm based on optimal wavelet parameters compared to classical discrete wavelet transform (DWT) or PCA-based spike sorting methods in decoding real intracortical data. Overall, the results indicate that it is possible to improve neural decoding performance by improving the spike sorting accuracy.
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The dorsal lateral geniculate nucleus (dLGN) is the main neuronal station en route to higher visual areas. It receives information about environmental light from retinal photoreceptors whose sensitivity peaks are distributed across a visible spectrum. Here, using electrophysiological multichannel recordings in vivo combined with different light stimulations, we investigated short wavelength contribution to the dLGN responses to light and irradiance coding. ⋯ Moreover, by using alternate yellow and monochromatic light stimuli from blue - UV range, we also assessed the relative spectral contribution to rat dLGN responses to light. Finally, we observed no clear changes in the irradiance coding property of short wavelength-deficient light stimuli, however we noticed a distortion of the coding curves manifested by a significant drop in measure of fit after using short wavelength blocking filter. In conclusion, our data provide the first electrophysiological report on dLGN short wavelength-induced responses under changing light conditions and suggest the presence of colour opponent cells in the rat dLGN.