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ObjectiveTo observe Semaphorins-3A and synaptophysin P38 expression in hippocampus of developing rat induced by status epilepticus.Methods 320 SD rats were divided into four groups (P7,P14,P21 and P28) according to day -old after birth (7d,14d,21d and 28d).Rats in each group were randomly divided into model group (SE group) and saline control group (NS group).SE was induced by Pentylenetetrazol (PTZ).Semaphorins-3A and synaptophysin P38 expression were determined by immunohistochemical staining on 1d,7d,14d,21d and 28d after SE in hippocampal CA1 of rats.ResultsSemaphorins-3A-positive cells could be seen in the hippocampal granule cell layer in all rats.Semaphorins-3A expression tended to decrease with the increasing of day-age,especially in P7 group(91 552.68 ± 4664.69 ).No matter how day-age,Semaphorins-3A expression was similar to that in NS group and was obvious reduced in 7d after SE(56 938.84 ± 5688.47 ).Meanwhile P38 expression in P7-day-age rats had had been gradually increasing between 1 day and 14d (5413.18 ±48.77,6223.40±29.19,6902.94 ±78.51 ) and then stabilized gradually on 21d(7523.42 ± 62.94) after rats were tested.P38 expression in other day-age rat was relatively stable on the same level in physiological state.On the other hand P38 expression in the hippocampal CA1 region of P7,P14,P21 and P28 rats was significantly higher than that in normal rats between 1day and 28day after SE episode(P＜ 0.05 ),and reached a peak on 14 day(8408.35 ± 55.73 ).ConclusionSemaphorins-3A and synaptophysin P38 involved in hippocampal synaptic plasticity of rat in developing stage and epilepsy.
RESUMEN
Objective To study the distribution and expression of Semaphorins-3A protein in brain of postnatal rats.Methods Semaphorins-3A positive cells were observed by immunohistochemistry in the cerebral cortex,hippocampus,dentate gyms and entorhinal cortex in postnatal 0d,7d,14d,21 d and 28d of Sprague Dawley rats.Results Semaphorins-3A positive cells widely distributed in the granule cell layer ( Ⅱ ),external pyramidal cell layer ( Ⅲ ),internal granular cell layer ( Ⅳ ),pyramidal cell layer ( Ⅴ ) and layer of polymorphous cells ( Ⅵ ),in addition to the molecular layer ( Ⅰ ) of the parietal,occipital,frontal,temporal,insular,cingulate cortex,piriform cortex and entorhinal cortex with postnatal 0d,7d,14d,21d and 28d rats.The amount of semaphorins-3A positive cells(IOD) in the entorhinal cortex was 84916.23 ± 3266.34 in P0d,77711.41 ± 2634.26 in P7d,74124.25 ± 3989.09 in P14d,65887.63 ± 3406.57 in P21d and 57705.96 ± 3136.35 in P28d,meanwhile the region of semaphorins-3A positive cells narrowed in the part level with Ⅱ -Ⅵ levels of cortex.Similarly semaphorins-3A positive cells distributed mainly in granule cell layer of dentate gyrus,CA1,CA3 region and only a few of semaphorins-3A positive cells scattered in the multi-line layer in hippocampus.The expression level of semaphorins-3Awas significant difference among postnatal 0d,7d,14d,21d and 28d rats (P＜0.01).Conclusion Semaphorins-3A positive cells widely distribute in the various cortex and hippocampus in developing rat brain,and the region of semaphorins-3A is reduced with age growth of rats.