Neuroscience
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The spontaneous action potential of isolated sinoatrial node (SAN) cells is regulated by a coupled-clock system of two clocks: the calcium clock and membrane clock. However, it remains unclear whether calcium clock inhibitors have a direct effect on the membrane clock. The purpose of this study was to investigate the direct effect of cyclopiazonic acid (CPA), a selective calcium clock inhibitor, on the function of the membrane clock of SAN cells. ⋯ These results indicate that the direct inhibition effect of CPA on the If current in SAN cells is both concentration- and time-dependent. The underlying mechanisms may involve slowing down steady-state activation and the downregulation of pacemaker channel protein expression.
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Ischemic postconditioning (PostC) is an endogenous neuroprotective strategy for cerebral ischemia induced by low activation of glutamate receptors. We have previously shown that the application of the mGluR1/5 agonist (S)-3,5-dihydroxyphenylglycine (DHPG) 5 min after 30 min of oxygen and glucose deprivation (OGD) reduces CA1 damage in organotypic hippocampal slices by activating the PI3K-Akt signalling pathway. In order to extend these data, we analysed the production of reactive oxygen species (ROS) and the glycogen synthase kinase 3β (GSK3β) signalling pathway. ⋯ This reduction was prevented by the PI3K inhibitor LY294002, indicating that there is a link between the PI3K/Akt pathway and the formation of ROS in the protective mechanisms of PostC. DHPG PostC also induces a transient increased in GSK3β phosphorylation and inactivation that is followed by nuclear accumulation of β-catenin, that probably lead to the up-regulation of neuroprotective genes. Our results propose GSK3β as new target for neuroprotection, therefore, we verified that the two GSK3β inhibitors N-(3-Chloro-4-methylphenyl)-5-(4-nitrophenyl)-1,3,4-oxadiazol-2-amine (TC-G 24) and LiCl are neuroprotective agents in OGD and also can be used as PostC agents.
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Although the recognition of facial expressions seems automatic and effortless, discrimination of expressions can still be error prone. Common errors are often due to visual similarities between some expressions (e.g., fear and surprise). However, little is known about the neural mechanisms underlying such a confusion effect. ⋯ No difference between high confusion and low confusion conditions was observed on the M170 component in either the FFA or the pSTS, whilst a difference between two conditions started to emerge in the late positive potential (LPP), with the low confusion condition eliciting a larger LPP amplitude in the FFA. In addition, the power of delta was stronger in the time window of LPP component. This confusion effect was reflected in the FFA, which might be associated with the perceptual-to-conceptual shift.
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The fact that neurobiological research is reliant upon laboratory-reared rodents is well known. The following paper discusses this topic broadly, but also aims to highlight other species used in the study of the nervous system and the evolution of animal species usage from the end of World War II through recent investigations. ⋯ Such a limitation in animal species causes many difficulties in the development of new therapies for various neuropsychiatric diseases. Based on numerous scientific publications, the advantages of using a greater diversity of species in neuroscience and the disadvantages of focusing on mice and rats are presented.
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The cerebellum is involved in the coordination of movement. Its cellular composition is dominated by GABAergic neuronal types, and glial cells are known to express functional receptors. GABAergic signaling regulates cell proliferation, differentiation, and migration during neurodevelopment. ⋯ The second population showed an outward-rectifying current-voltage relationship and responded to muscimol, but dye coupling was absent. These cells received synaptic input and were NG2+, but evoked calcium waves failed to modulate the frequency of spontaneous postsynaptic currents (sPSCs) or signaling into NG2 glia. We conclude that GABAA receptor-mediated signaling is selective for NG2 glia in the WM of the cerebellum.