Neuroscience
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Despite the recommendation of improving assessment objectivity and frequency, the use of immersive virtual reality to measure and quantify movement quality remains underexplored. In this study, we aimed to evaluate the reliability, validity and usability of an immersive virtual reality application, KinematicsVR, to assess upper limb kinematics among older adults with and without major neurocognitive disorder. The KinematicsVR involves the drawing of three-dimensional straight lines, circles and squares using a controller in a virtual environment. ⋯ Secondary analyses showed that the usability of the application was excellent but few significant and strong correlations were observed between variables of the KinematicsVR and the scores of the TEMPA scale, Finger-Nose Test and BBT-VR. Adults with major neurocognitive disorder, when compared to other older adults, made larger and less linear hand movements. These findings provide perspectives for the use of immersive virtual reality to improve assessment frequency and objectivity through the autonomous measure of upper limb kinematics in older adults.
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The main clinical manifestation of Alzheimer's disease is progressive cognitive decline, and its pathological features are β-amyloid (Aβ) deposition, neurofibrillary tangles, synaptic dysfunction and neuron death. Neuroinflammation is an important reason for the occurrence and development of AD, which is mainly manifested by the accumulation of activated microglia and reactive astrocytes. Apolipoprotein E (ApoE) is one of the most important apolipoprotein in the brain, which is related to metabolism, aggregation and toxicity of Aβ. ⋯ In this study, we studied the effect of ApoE mimetic peptide COG1410 on spatial learning and memory functions, deposition of Aβ in the dentate gyrus (DG) of APP/PS1 transgenic mice, and the different effects of A1 and A2 subtypes of reactive astrocytes. Administration of COG1410 effectively improved performance in spatial learning and memory of APP/PS1 mice, reduced Aβ deposition and significantly reverted the ratio of A1/A2 reactive astrocytes, which could be associated with BDNF/TrkB signaling pathway. On the whole, the present findings suggest new possibility of using apolipoprotein E mimetic peptide to treat AD with potential effectiveness.
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The lateral parabrachial nucleus (LPBN) is known to play a key role in relaying noxious information from the spinal cord to the brain. Different LPBN efferent mediate different aspects of the nocifensive response. However, the function of the LPBN → lateral hypothalamus (LH) circuit in response to noxious stimuli has remained unknown. ⋯ Optogenetic inhibition inhibited jumping behavior to noxious heat. Ablation of LH glutamatergic neurons could abolish light-evoked analgesia and jumping behavior. Our study revealed a role for the LPBN → LH pathway in nocifensive behaviors.
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In both people and animals, exposure to adverse experiences early in life can alter neurodevelopment and lead to long-term behavioral effects, including effects on reward processing. In the current study, we use a well-validated rodent model of maternal neglect, maternal separation (MS), to investigate the impact of early life adversity on reward learning and motivation and identify associated modifications in cellular activation in reward-relevant areas. Litters of Long-Evans rats were separated from the dam for either 15 min (brief) or 180 min (prolonged)/day from postnatal day (PND)2 to PND14. ⋯ MS180-induced changes in c-Fos expression in the dorsal and ventral striatum were observed, with subregion-specific effects along the rostrocaudal axis. Moreover, regression analyses suggest that motivated responding for a sucrose food reward in MS180-exposed, but not MS15-exposed animals, was associated with increased c-Fos expression in the rostral nucleus accumbens core. These findings implicate specific striatal regions in sex-specific modulation of sustained effort-based reward behavior following early life adversity.
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Thioredoxin system plays an important role in maintaining the cellular redox balance. Recent evidence suggests that thioredoxin (Trx) system may promote cell survival and neuroprotection. In this study, we explored the role of thioredoxin system in neuronal differentiation using a primary mouse cortical neuronal cell culture. ⋯ However, treatment with CB3, a Trx-mimetic tripeptide, rescued H2O2-decreased CREB phosphorylation. Our results suggest that Trx regulates neuronal differentiation and maturation of primary mouse cortical neurons by targeting CREB neurotrophic pathway. Trx may regulate CREB activation by maintaining the cellular redox balance.