Experimental study of effect of corticosterone on primary cultured hippocampal neurons and their Ca2+/CaMKII expression / 华中科技大学学报（医学）（英德文版）

To explore the effect of different concentrations of corticosterone (CORT) on primary cultured hippocampal neurons and their Ca2+/CaMK II expression and possible mechanism, the changes of hippocampal neurons were observed in terms of morphology, activity of cells, cell death, concentrations of cytosolic free calcium, and the expression of CaMK II by using MTT assay, flow cytometry, fluorescent labeling of Fura-2/AM and Western blotting after 10(-7), 10(-6) and 10(-5) mol/L of CORT was added to culture medium, The evident effect of 10(-6) and 10(-5) mol/L of CORT on the morphology of hippocampal neuron was found. Compared with control neurons, the activity of the cells was markedly decreased and [Ca2+]i increased in the neurons treated with 10(-6) and 10(-5) mol/L of CORT, but no change was observed in the neuron treated with 10(-7) mol/L of CORT. The death was either by way of apoptosis or necrosis in the cells treated with 10(-6) and 10(-5) mol/L of CORT respectively. The correlation analysis showed that a reverse correlation existed between [Ca2+]i and the expression of CaMK II. Either apoptosis or necrosis occurs in the hippocampal neurons treated with CORT. The increased hippocampal [Ca2+]i is both the result of CORT impairing the hippocampal neurons and the cause of the apoptosis of hippocampal neurons and the decreased CaMK II expression.

PROLIFERATION AND EXPRESSION OF HIPPOCAMPAL CELLS AND CHANGE OF POSTSYNAPTIC DENSITY Fyn IN THE HIPPOCAMPUS OF THE RAT WHOSE LEARNING AND MEMORY WAS ENHANCED BY CHRONIC MULTIPLE STRESS / 解剖学报

Objective To investigate the changes and the significance of the number of nerve cells and the expression of the postsynaptic density tyrosine kinase(Fyn) in the hippocampus of the rat whose spatial learning and memory function was enhanced by chronic multiple stress. Methods Thirty-nine adult rats were randomly divided into three groups: multiple stressed,single stressed and control group.Rats in the multiple stressed group were irregularly and alternatively exposed to the situation of vertical revolve,sleep expropriate,restraint(6h/d),and night illumination for 6 weeks,to preparate chronic multiple stressed model.Rats in the single stressed group were exposed to restraint only for 6 weeks,6h/d.After that,the performance of spatial learning and memory of all rats was measured using Morris water maze.Nerve cells in different subfields of the hippocampus were observed using Cresyl violet method and counted regardless of size or shape.The expression of Fyn protein and the level of Fyn mRNA in the hippocampus of rats were detected by immunohistochemical method and RT-PCR technique respectively. Results Compared with control group,the performance of spatial learning and memory of rats was increased in multiple stressed group and decreased in single stressed group((P

THE ULTRASTRUCTURAL ORGANIZATION OF CALCITONIN GENERELATED PEPTIDE(CGRP)-IMMUNOREACTIVE NERVE FIBRES AND LOCALIZATION OF THE IMMUNOREACTIVITIES IN THE GUINEA-PIG STELLATE GANGLION / 解剖学报

Using the immunohistochemical streptavidin-biotin-peroxidase complex tech- nique, the ultrastructure and localization of calcitonin gene-related peptide(CGRP)- immunoreactive nerve fibres were investigated in the stellate ganglion of guinea pig. The immunoreactive fibres were nonmyelinated and composed of nonvaricose and varicose parts. The latter was again divided into varicosities and intervari- cose segments. The immunoreactive varicosities contained many small clear vesi- cles, large cored vesicles and a few mitochondria, etc. They formed asymmetric or symmetric axodendritic and axosomatic synaptic contacts with nonreactive neuronal dendrites and somata as well as unspecialized appositions to them. The varicosities and intervaricose segments were partly exposed to the interstitial space. The CGRP-immunoreactivities were mainly localized in the axoplasmic ransport granules of the nonvaricose part, cytoplasma of the intervaricose segment, and the dense cores of the large cored vesicles of the varicosities. These obser- vations suggested that the CGRP could be also released by nonsynaptic diffusion in addition to synaptic release. The origins of the CGRP-immunoreactive fibres in the stellate ganglion of guinea pig were discussed.