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In recent years, the rapid development of stem cell transforming technology and regeneration pose great re?search value. With maturation of transformation induction, other cell lineages were shown to be able to transform into neu?rons. In addition, astrocytes are widely distributed in the gray and white matter of the central nervous system, whose exces?sive proliferation contribute to glial fibrillary scar formation, which is the key obstacle in recovery of neurological function. Therefore, the study of transforming astrocytes into neurons draw attention from many scientists. Astrocytes transformation not only prevent the formation of glial scar, but also generate new neurons. This article summarized relevant studies that re?port function of astrocytes and its transformation into neurons.
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Objective To investigate the effect of the overexpression of NeuroD1 on mediating transdifferentiation of spinal reactive astrocytes into neurons. Methods Spinal cord astrocytes were cultured from the SD rat, and reactive astrocytes were prepared by scratches treatment. Cells were divided into blank groups (NV group), control virus group (GFP group) and NeuroD1 virus group (NeuroD1 group). At 7 d after scratches treatment, GFP and NeuroD1 groups were infected with retroviruses carrying the GFP gene and and GFP gene plus NeuroD1 gene, respectively,whereas NV group was not infected with the virus. Twenty-four hours late, the culture medium were replaced by neuron conditioned medi?um. Cell morphology was examined at 1, 2, 3, 5, 7 and 14 d. DCX positive and NeuN positive cells were detected at 7 d and 14 d after infection by using immunofluorescence staining method, respectively. Results After replacement with the neuron conditioned medium, the nucleus was obviously plump, the cytoplasm was thin and neurites was reduced and ex?tended. Compared with the NeuroD1 group, neurites of NV group and GFP group were shorter with many branches and the nucleus was smaller. At 7 d after infection, cell morphology of NV group and GFP group gradually recovered, but cell morphology of NeuroD1 group did not. Compared with NV group and GFP group, NeuroD1 group had more DCX(9.84 ± 2.06%)and NeuN(8.25±2.78%)positive cells [F values 40.107 for DCX and 21.73 for NeuN (P<0.05)]. Conclusion The overexpression of NeuroD1 can mediate the transdifferentiation of spinal reactive astrocytes into neurons.
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Objective To analyze the efficacy of kaolin intake amount as an index for motion sickness (MS)induced by different motion patterns stimulating the vestibular receptors of rats.Methods Rats were randomly divided into 5 groups.Three groups were subjected to one of the following stimulations,respectively-linear acceleration along either the interaural axis(IA)or body axis (AP),and double rotation(DR)stimulation.Other 2 groups were used as control.Kaolin intake was recorded for consecutive 6 d,3 d before and 3 d after stimulation,and the data were statistically analyzed.Results It was found that:1)following IA,AP and DR stimulations,25%,17% and 58% of the rats in each group increased mean kaolin intake by 1 g in the 3 d phase post-stimulation compared with that in the same duration of pre-stimulation,respectively;2)in contrast to some prewous reports,the present observation showed that high Ievel of kaolin intake post-stimulation may persist for more than one day.Conclusion All 3 tvpes of stimulation methods can serve as ways of specifically stimulating vestibular end-organs to induce kaolin intake increase,and double rotation iS the most effective.