Neuroscience
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Ethanol is one of the most widely used drugs - with many psychoactive effects, including anxiolysis. The deleterious effects on brain function and general health of chronic and high-level ethanol use are well-studied. However, the neurophysiology of acute low dose ethanol has not been systematically investigated. ⋯ We conclude low dose ethanol has weak but detectable effects on neocortical and hippocampal theta oscillations. These effects may underlie positive cognitive and behavioural outcomes reported in the literature using low dose ethanol. The double dissociation of slope and y-intercept specific changes relating to different methods of hippocampal theta elicitation presents the potential to probe multiple mechanisms contributing to anxiolytic effects on theta and so hippocampal function.
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Age-related hearing loss affects the ability to hear high frequencies and therefore leads to difficulties in understanding speech, particularly under adverse listening conditions. This decrease in hearing can be partly compensated by the recruitment of executive functions, such as working memory. The compensatory effort may, however, lead to a decrease in available neural resources compromising cognitive abilities. ⋯ Cognitive flexibility and hearing abilities further predicted speech-in-noise perception. We conclude that neural and behavioral signatures of working memory are intact in mild to moderate hearing loss. Moreover, cognitive flexibility seems to be closely related to hearing impairment and speech-in-noise perception and should, therefore, be investigated in future studies assessing age-related hearing loss and its implications on prefrontal functions.
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Large scale unbiased quantification of immunohistochemistry (IHC) is time consuming, expensive, and/or limited in scope. Heterogeneous tissue types such as brain tissue have presented a further challenge to the development of automated analysis, as differing cellular morphologies result in either limited applicability or require large amounts of training tissue for machine-learning methods. Here we present the use of QuPath, a free and open source software, to quantify whole-brain sections stained with the immunohistochemical markers IBA1 and AT8, for microglia and phosphorylated tau respectively. ⋯ This method is fast, automated, unbiased, and easily replicable. We compared swine brains that had undergone a closed head traumatic brain injury with brains of sham animals, and found a global increase in both microglial signal expression and phosphorylated tau. We discuss the IHC methods necessary to utilize this analysis and provide detailed instruction on the use of QuPath in the pixel-based analysis of whole-slide images.
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Environmental enrichment has been shown to increase cognitive abilities and accelerate recovery from a number of disease states. Typically, enrichment protocols last from four to eight weeks, however, it has previously been shown that two weeks of environmental enrichment is sufficient to increase cognitive abilities and the proliferation of the astroglial stem cell pool in juvenile mice. The current study examines whether a short-term enrichment protocol can induce similar effects in adults as compared to juveniles. ⋯ We found that short-term environmental enrichment decreased anxiety behaviour and increased overall memory abilities similarly in juveniles and adults. However, the rate of acquisition on the Morris water maze, hippocampal Sox2 and Ki67 expression, and neurosphere potential increased in response to enrichment only in juveniles, suggesting that the effects of enrichment on these measures are age dependant. Together, these data suggest that the potential beneficial effects of environmental manipulations decrease with age.
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Exercise affects positively on self-reported pain in musculoskeletal pain conditions possibly via top-down pain inhibitory networks. However, the role of cortical activity in these networks is unclear. The aim of the current exploratory study was to investigate the effects of acute exercise on cortical nociceptive processing and specifically the excitability in the human sensorimotor cortex. ⋯ In conclusion, acute exercise may have an effect on nociceptive processing in the sensorimotor cortex on oscillatory level. Research on cortical oscillations analyzing interaction between nociception and exercise is limited. This study presents results indicating brain oscillatory activity as a feasible research target for examining mechanisms interacting between exercise and cortical nociceptive processing.