Abstract

Objective：To study the influence of morphine on the expression of nestin in the ependymal epithelia,central gray and hippocampal formations in mice.Methods: Twenty health mice were evenly randomized into control group and experiment group.Mice in the control group were injected with normal saline (0.1 ml daily) and those in the experimental group were injected with morphine (0.1 ml,1 mg daily) .Thirty days later,the mice brain samples were harvested and made into paraffin sections.Immumohistochemical ABC technique was used to observe the expression of nestin under light microscope.The images were analyzed with the image analytical system.Results: In the control group,the ependymal epithelia,the central gray,the periventricular gray substances and the hippocampal formations had weak expression of the nestin,with a mean gray scale of 150.98±13.31; there were 5 kinds of nestin-positive cells: (1) the basal cells of ependymal epithelium,(2) cells distributed in the periventricular gray substance and the deep lamella of central gray,(3) cells distributed in the superficial lamella of central gray,the subiculum,the parahippocampal gyrus and the cortex in Ⅱ,Ⅲ layers of the entorhinal area,(4) cells frequently seen in the tectum of midbrain and the subiculum,and (5) cells distributed in the tectum of midbrain,the hippocampus,gyrus dentatus,parahippocampal gyrus and the cortex in Ⅴ layer of the entorhinal area; the density of nestin in the subiculum and entorhinal area was (7.20±1.23) mm2.In the experiment group,the ependymal epithelia,the central gray,the periventricular gray substances and the hippocampal formations had positive expression of the nestin,with the mean gray scale being 133.03±22.28; the density of the above-mentioned 5 kinds of cells increased; the density of nestin in the subiculum and entorhinal area was (10.50±1.43) mm2.The mean value of gray scale and nestin-positive neurons were significantly different between the 2 groups (P<0.05).The cellular proliferation was seen in the ependymal epithelia.The second kind of cells appeared in the superficial lamella of central gray,parahippocampal gyrus and the cortex in Ⅰ,Ⅱ and Ⅲ layers of the entorhinal area.The third kind of cells increased in the hippocampal pyramidal layer and the fourth kind of cells increased in the tectum of midbrain and the subiculum.Conclusion: Morphine can promote nestin expression in the ependymocyte,the central gray,the periventricular gray substance and the hippocampal formation; it can also promote the proliferation,differentiation and migration of the ependymocytes and neurocytes.

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