Objective Monocular deprivation(MD) and binocular deprivation(BD) were used to examine the experience\|dependent structural plasticity of astrocytes in the central visual brain regions of young rats. Methods Pups eyelids were monocularly or binocularly sutured on postnatal day 7(P7) and maintained until 80?d,while an unoperated light experienced group was used for comparisions(L).Immunohistochemical ABC method was employed to investigate the immunoreactive changes of astrocytic bodies and processes for glial fibrillary acidic protein(GFAP) in the central visual brain regions. Results The results showed that the amount of astrocytic bodies and processes in the brain was decreased both in MD and BD groups compared to L group.The amount of GFAP\|positive immunoreactivity in the optic chiasma,optic tract,and contralateral central visual brain regions (including suprachiasmatic nucleus,lateral geniculate nucleus,occipital visual cortex,optic nerve layer of the superior colliculus and pretectal area) was significantly decreased in MD group.GFAP\|positive structures presented complementary distribution in bilateral visual cortex.For bilateral brain regions mentioned above,the amount of GFAP\|positive structures basically disappeared in BD group.There was,however,an increase in the olfactory cortex of GFAP immunoreactive in MD and BD groups. Conclusion\ The data suggested that the structure of astrocytes might be influenced by visual experience during development.

Objective To detect the location of histamine in peripheral sympathetic nerves of guinea pig. Methods Histidine decarboxylase mRNA was detected using in situ hybridization histochemistry with specific oligonucleotide probe,while histamine and tyrosine hydroxylase were detected using double labeled immunohistochemistry with anti-histamine antibody and anti-tyrosine hydroxylase antibody in the superior cervical ganglia of guinea pig. Results The histidine decarboxylase mRNA hybridization signal were detected in both of large and small cells.The TH immunoreactive substance distributed in cytoplasm steadly,but lacked in the nuclei,while the histamine immunoreactive substance distributed in cytoplasm nearby the plasmalemma.After chemical destroy of the guinea pig SCG′s neuron with 6-OHDA,the immunoreactive materials were hardly detected.Conclusion Because the histidine decarboxylase is the only enzyme which catalyzes histidine into histamine,histamine may be synthesized and coexisted with monoaminergic neurotransmitters in the superior cervical ganglia of guinea pig.

Objective To investigate the early effect of medium-dose ionic irradiation on the expression of Fos protein in the rat brain. Methods Fos protein was observed in rat brains at times ranging from 24 hours to 4 weeks after hemispheric irradiation (single-fraction maximal dose of 20Gy) with the immunohistochemical technique. Results Compared with that of the un-radiated rats,the expression of Fos protein in the irradiated brain decreased distinctly 24 hours and 1 week after irradiation.However,the quantity of Fos immunopositive cells increased gradually afterwards.At four weeks after radiation,expression of Fos protein recovered progressively in medulla oblongata and pons,in which Fos immunopositive cells were more than those in control group.In contrast,expression level of Fos protein in mesencephalon,diencephalons or telencephalon was still less compared with that of the un-irradiated rats.Conclusion The result suggested that the neuronal activity might be inhibited in certain nuclei of the rat brain in early stages after hemisphere irradiation,and this inhibitory phenomenon was more obviously in higher neural centers.

BACKGROUND: It is considered traditionally that epilepsy is a kind of complicated nervous conduct disorder caused by abnormally excited neuron in different area in brain. While the research on the function of astrocyte in epileptic attack is very rare.OBJECTIVE: To study the reaction of neuron and astrocyte in medullary visceral zone after epilepsy induced by pentetrazole in rats.DESIGN: A randomized controlled experimental research.SETTING and MATERIALS: The experiment was done in the Neurosurgery Laboratory of Zhujiang Hospital Affiliated to Southern Medical University and Neuroscience Institute of Fourth Military Medical University of Chinese PLA. Fourteen healthy adult SD rats, weighing 180 - 220 g, clean grade, were provided by the Experimental Animal Center of Fourth Military Medical University of Chinese PLA.INTERVENTIONS: Distribution of neuron and astrocyte in MVZ 1 hour after epileptic attack was shown by laserconfocal microscopic technique combined with triplication immunofluorescence histochemistry of anti-Fos protein, anti-tyrosine hydroxylase(TH) and anti-glial fibrillary acidic protein(GFAP).MAIN OUTCOME MEASURES: Observation of distribution of positive cells of Fos, GFAP and TH in MVZ and relationship between GFAP positive astrocyte and neuron.RESULTS: Fos positive neurons and GFAP positive astrocytes in MVZ increased significantly. Triplication immunofluorescence histochemistry showed reaction neuron(Fos positive) closely related with reaction astrocyte(GFAP positive) . Three kinds of N-ASC compounds with different labels were found, which were TH +/Fos +/GFAP + three labeled compound, TH + /GFAP +/Fos- and Fos+/GFAP +/TH- two labeled compound.CONCLUSION: Neuron and astrocyte in MVZ reacted strongly when epilepsy attacks. N-ASC as a functional unit may regulate onset of epilepsy.

BACKGROUND: Lipopolysaccharide(LPS), as a polyclonal immune exciter, can simulate immune excitation status, which is useful in the observation of whether the catecholaminergic neurons in paraventricular nucleus of hypothalamus(PVN) projected from medullary visceral zone(MVZ) react towards LPS stimulation that is to provide a theoretical gist for the researches on the protection of brain function.OBJECTIVE: To observe whether PVN catecholaminergic neurons projected from MVZ react towards LPS stimulation for the exploration of the impacts of MVZ-PVN catecholaminergic access in "immune-to-brain communication".DESIGN: A randomized controlled study using experimental animals as subjects.SETTING: An Institute of Neurosurgery and Neurology of one Military University of Chinese PLA.MATERIALS: The study was conducted in the Department of Neurosurgery of Zhujiang Hospital affiliated to Southern Medical University and the Institute of Neurology of the Fourth Military Medical University of Chinese PLA from January to December in 2002. Ten healthy adult SD rats in cleanness grade were obtained from the experimental animal center of the Fourth Military Medical University of Chinese PLA.METHODS: WGA-HRP was injected into PVN of one side of the rat, and the immune exciter LPS was injected into the abdominal cavity after 48 hours of survival to induce immune response. Samples were stained by triple labels of WGA-HRP method and double immunohistochemical staining of anti-Fos and anti-TH antibodies.MAIN OUTCOME MEASURES: To observe the distributions and expressions of WGA-HRP labeled cells, Fos protein, and catecholaminergic neuron(labeled by TH) in MVZ.RESULTS: Seven immune-reactive(IR) positive neurons were found in MVZ, i. e., HRP, Fos or TH single labeled cells, Fos/HRP, Fos/TH or HRP/TH double labeled cells, and Fos/HRP/TH triple labeled cells. Fos/HRP double labeled neurons and Fos/HRP/TH triple labeled neurons accounted for 12. 5% and 39.6% of HRP labeled cells respectively.CONCLUSION: MVZ reacts to LPS immune stimulation, which could upload the immune message to PVN through Catecholaminergic neurons.MVZ might be a relay station in "immune-to-brain communication", which exerts immune modulatory impact through "MVZ→PVN" access.

Autophagy is an intracellular degradation process that maintains cellular homeostasis. It is essential for protecting organisms from environmental stress. Autophagy can help the host to eliminate invading pathogens, including bacteria, viruses, fungi, and parasites. However, pathogens have evolved multiple strategies to interfere with autophagic signaling pathways or inhibit the fusion of autophagosomes with lysosomes to form autolysosomes. Moreover, host cell matrix degradation by different types of autophagy can be used for the proliferation and reproduction of pathogens. Thus, determining the roles and mechanisms of autophagy during pathogen infections will promote understanding of the mechanisms of pathogen‍‒‍host interactions and provide new strategies for the treatment of infectious diseases.
Autophagy ; Bacteria ; Host-Pathogen Interactions ; Lysosomes ; Signal Transduction

Objective: To investigate the effects of human adult T lymphoblastic leukemia virus typeⅠ (HTLV-1) infection on the production of reactive oxygen species (ROS) and mitochondrial damage in host cells. Methods: A cell model of HTLV-1 infection was established by co-culturing HTLV-1-positive cell line MT2 with HeLa cells. ROS, mitochondrial membrane potential (MMP) and total mitochondria were detected using specific fluorescence probe labeling method. Cell apoptosis was detected by Annexin V-FITC/PI method. Western blot was performed to detect viral proteins Tax and p19, as well as mitochondrial proteins TIM23 and TOM20. After the treatment of MT2 cells with different concentrations of reverse transcription inhibitors (ZDV), relative viral loads were detected by quantitative real-time PCR and Western blot, and the mass of mitochondria was analyzed by flow cytometry. Results: After co-culturing HeLa cells with MT2 cells for 24 h, the ROS level in host cells increased without obvious cell apoptosis, while the mitochondrial membrane potential, mitochondrial protein expression and total mitochondria decreased significantly. When the replication of HTLV-1 in MT2 cells was inhibited by ZDV, the ROS level and total mitochondria increased. Conclusions HTLV-1 infection can cause oxidative stress in host cells, resulting in mitochondrial damage. Autophagy might be activated to degrade mitochondrial damage and maintain cell homeostasis during the infection.