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This paper, from the aspects of neuroendocrine, emotion, learning etc, analyzed comprehensively the characteristics of the influence of prenatal stress (PS) on offspring, including intensity of PS, timing of exposure and individual differences. Despite the variety in methodology, most studies on it indicate that the prenatal stressful events lead to offspring's increased plasma glucocorticoid (GC) level, more depressed-related behaviors and impaired learning abilities. Although mechanism of prenatal stress is still unclear, most studies show that it is concerned with hypothalamio-pituitary-adneral (HPA) axis,dopaminergic (DA-ergic) system, neuropeptide Y (NPY)and serotoninergic (5-HT ergic) system. Moreover, further studies are proposed to pay more attention to the relationship and interaction of various related substances.
RESUMO
Objective To study the temporo-spatial changing laws of calcitonin gene-related peptide(CGRP)in the rat model of sciatic nerve ligation.Methods Totally 48 Sprague-Dawley rats were randomly divided into sham-operation group(n=6)and experimental groups which survived for 1,3,5,7,14,21,28 d respectively after sciatic nerve ligation(n=6 at each time point).The distribution and quantity of CGRP in sciatic nerve,dorsal root ganglion(DRG)and spinal cord were detected by immunohistochemistry and image analysis methods.Results A large amount of CGRP piled up in the sciatic nerve at 1 d after the ligation,significantly higher in proximal segment than that in distal segment,gradually dropping till disappear basically at 14 d in proximal segment and at 7 d in distal segment.The expression of CGRP in DRG at 7 d began to drop after the ligation,at 21 d to the minimal value and at 28 d lower than normal.The CGRP-immunoreactivety in ipsilateral spinal dorsal horn at 14 d decreased after operation,but the immuno-positive areas of CGRP were of no changes.There are no changes in the CGRP-positive spinal ventral motoneurons of all groups.Conclusion The changes of CGRP presented a temporo-spatial pattern following peripheral nerve legation,maybe resulting from the deficiency of neurothrophins from target organs.