Neuroscience
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The article reviews evidence for sensitive periods in the sensory systems and considers their neuronal mechanisms from the viewpoint of the system's neuroscience. It reviews the essential cortical developmental steps and shows its dependence on experience. It differentiates feature representation and object representation and their neuronal mechanisms. ⋯ Additional to developmental molecular effects on synaptic plasticity, a combination of several integrative effects of deprivation on brain functions, including feature representation (affecting the starting point for learning), categorization function, top-down interactions and cross-modal reorganization close the sensitive periods and may contribute to their critical nature. Further, non-auditory effects of auditory deprivation are discussed. To reopen critical periods, removal of molecular breaks in synaptic plasticity and focused training therapy on the integrative effects are required.
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Randomized Controlled Trial
Illumination influences working memory: an EEG study.
Illumination conditions appear to influence working efficacy in everyday life. In the present study, we obtained electroencephalogram (EEG) correlates of working-memory load, and investigated how these waveforms are modulated by illumination conditions. We hypothesized that illumination conditions may affect cognitive performance. ⋯ The fact that the illumination condition affects brain activity but not behavioral performance suggests that the lighting conditions used in the present study did not influence the performance stage of behavioral processing. Nevertheless, our findings provide objective evidence that illumination conditions modulate brain activity. Further studies are necessary to refine the optimal lighting parameters for facilitating working memory.
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Hyperbaric oxygen-induced seizures are classified as brief, generalized tonic-clonic seizures. They are believed to cause no residual cognitive damage, although this has not been investigated in depth. In the present study, we examined whether hyperbaric oxygen-induced seizures cause impairment of behavioral and cognitive abilities. ⋯ We conclude that hyperbaric oxygen-induced seizures result in transient impairment of performance on behavioral tests in a mouse model. Further investigation is required to establish the mechanism and location of injury, and to determine whether the performance decrement on the elevated plus maze test represents permanent damage or transient damage with slow resolution. These new findings should be taken into account when planning hyperbaric oxygen treatments, to ensure that the chosen protocol is therapeutic yet minimizes the risk of CNS oxygen toxicity.
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Accumulating evidence indicates that activation of spinal cord astrocytes contributes importantly to nerve injury and inflammation-induced persistent pain and chronic opioid-induced antinociceptive tolerance. Phosphorylation of extracellular signal-regulated kinase (pERK) and induction of interleukin-1 beta (IL-1β) in spinal astrocytes have been implicated in astrocytes-mediated pain. Tissue plasminogen activator (tPA) is a serine protease that has been extensively used to treat stroke. ⋯ Intrathecal injection of tPA results in up-regulation of GFAP and pERK in spinal astrocytes but not up-regulation of ionized calcium binding adapter molecule 1 in spinal microglia. Finally, intrathecal tPA elicits persistent mechanical allodynia, which is inhibited by the astroglial toxin alpha-amino adipate and the MEK (ERK kinase) inhibitor U0126. Collectively, these data suggest an important role of tPA in regulating astrocytic signaling, pain hypersensitivity, and morphine tolerance.
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Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. ⋯ In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.