Neuroscience
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We recently showed that vestibular stimulation can produce a long-lasting alleviation of motor features in Parkinson's disease. Here we investigated whether components of the motor related cortical response that are commonly compromised in Parkinson's - the Bereitschaftspotential and mu-rhythm event-related desynchronization - are modulated by concurrent, low frequency galvanic vestibular stimulation (GVS) during repetitive limb movement amongst 17 individuals with idiopathic Parkinson's disease. Relative to sham, GVS was favourably associated with higher amplitudes during the late and movement phases of the Bereitschaftspotential and with a more pronounced decrease in spectral power within the mu-rhythm range during finger-tapping. These data increase understanding of how GVS interacts with the preparation and execution of voluntary movement and give added impetus to explore its therapeutic effects on Parkinsonian motor features.
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Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disorder caused by mutant ataxin-3 with an abnormally expanded polyQ tract and is the most common dominantly inherited ataxia worldwide. There are no suitable therapeutic options for this disease. Autophagy, a defense mechanism against the toxic effects of aggregation-prone misfolded proteins, has been shown to have beneficial effects on neurodegenerative diseases. ⋯ Western blot and total antioxidant capacity assays suggested that trehalose had great therapeutic potential for treating SCA3, likely through its antioxidant activity. Our data indicate that trehalose plays a neuroprotective role in SCA3 by inhibiting the aggregation and reducing the protein level of ataxin-3, which is also known to protect against oxidative stress. These findings provide a new insight into the possibility of treating SCA3 with trehalose and highlight the importance of inducing autophagy in SCA3.
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Drosophila phototransduction in light-sensitive microvilli involves a metabotropic signaling cascade. Photoisomerized rhodopsin couples to G-protein, activating phospholipase C, which cleaves phosphatidylinositol bisphosphate (PIP2) into inositol trisphosphate, diacylglycerol (DAG) and a proton. DAG is converted into phosphatidic acid by DAG-kinase and metabolized to L-linoleoyl glycerol (2-LG) by DAG-lipase. ⋯ The channels were opened by mechanical force, while mutant lacking both channels was insensitive to mechanical stimulation. Atomic Force Microscopy showed that the stiffness of an artificial phospholipid bilayer was increased by arachidonic acid and diacylglycerol whereas elaidic acid was ineffective, mirroring their relative effects in channel activity previously observed electrophysiologically. Together, the results are consistent with the notion that light-induced changes in lipid composition alter the membrane structure, generating mechanical force on the channels leading to channel opening.
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Exposure to environmental microplastics has been demonstrated to impact health. However, its effect on development remains unclear. This study investigated whether consumption of nanoplastics (NPx) during development affects social and cognitive functions in rodents. ⋯ Social behavior was similarly affected by NPx treatment, with GTD13 and PND56 groups displaying decreased familiarity. Additionally, NPx treatment enhanced local field potentials in the prefrontal cortex, nucleus accumbens, and amygdala of GTD7 group and in the striatum of GTD13 group, while amphetamine treatment induced changes of local field potentials compared to saline treatment in the prefrontal cortex and the ventral tegmental area of CTR, GTD7, PND21, and PND56 groups. Taken together, these results showed that NPx treatment induced changes in social behavior partly depending on developmental stage, and these changes are associated with neural circuits innervated by the dopamine system.
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Oxytocin affects social recognition, interactions, and behavior in adults. Despite growing data on the role of oxytocin in the sensory systems, its effects on early olfactory system development remain poorly understood. ⋯ Oxytocin administration markedly reduced the expression of the scaffolding protein Gephyrin in male rats and it led to a significant increase in the number of GABAergic synaptic puncta in the piriform cortex of male rats at P5, P7, and P9. Our data suggest that the developmental action of oxytocin in relation to the GABAergic system may represent a mechanism by which the plasticity and maturation of olfactory brain regions are regulated.