Unique Hippocampal Changes and Allodynia in a Model of Chronic Stress

Sustained stress can have numerous pathologic effects. There have been several animal models for chronic stress. We tried to identify the changes of pain threshold and hippocampus in a model of chronic stress. Male Sprague-Dawley rats were kept in a cage filled with 23degrees C water to a height of 2.2 cm for 7 days. Nociceptive thresholds, expressed in grams, were measured with a Dynamic Plantar Aesthesiometer. Golgi staining was used to identify hippocampal changes. To demonstrate how long allodynia was lasting, behavioral test was repeated daily on another experiment. Compared to control group, chronic stress group showed bilateral mechanical hyper-responsiveness on days 5 (P = 0.047) and 7 (P = 0.032). In general, dendrite atrophic changes within hippocampus of chronic stress model were much more prominent in comparison with control. Compared to control, decreased spine number (P < 0.001) and spine length (P < 0.001) on Golgi staining were seen in the hippocampus of animals with chronic stress. Bilateral mechanical hyperresponsiveness was recovered on day 19 in animals with chronic stress. Chronic stress may bring about central sensitization and hippocampal changes in rats.

Dendritic eIF4E-binding Protein 1 (eIF4E-BP1) mRNA Is Upregulated by Neuronal Activation

Long-term synaptic plasticity requires addition of new proteins at the synaptic site. The local protein synthesis at subsynaptic sites confers advantageous mechanisms that would regulate the protein composition in local domains on a moment-by-moment basis. However, our information on the identities of 'dendritic' mRNAs is very limited. In this study we investigated the expression of the protein and mRNA for eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4EBP1) in cultured rat hippocampal neurons. Immunocytochemistry (ICC) showed that 4EBP1 protein is highly localized to the nucleus. In dendrites most 4EBP1 punctae were not colocalized with those of eIF4E. In situ hybridization (ISH) and Fluorescence ISH (FISH) revealed that 4EBP1 mRNA was present in dendrites. The FISH signals formed clusters along dendrites that colocalized with ICC signals for Staufen, a marker for RNA granules. The neuronal activation by KCl (60 mM, 10 min) significantly increased the density of 4EBP1 FISH signals in the nucleus after 2 hr, and both in the nucleus and dendrites after 6 hr. Our results indicate that 4EBP1 and its mRNA are present in dendrites, and the mRNA is upregulated and transported to dendritic domains in RNA granules upon neuronal activation.

Serotonin Changes in Specific Brain Regions of Fibromyalgia Animal Model after Deep-sea Water Drinking / 대한류마티스학회지

OBJECTIVE: The acidic saline animal model of pain has been suggested to mimic fibromyalgia (FM). In this model, repeated intramuscular (IM) injections of acidic saline produce a widespread hyperalgesia that persists without evidence of significant peripheral tissue damage or inflammation, and is believed to be centrally maintained. We examined the changes of pain-related neurotransmitters in specific brain regions of this model after deep-sea water (DSW) drinking. METHODS: Rats were injected with 100microliter of acidic saline (pH 4.0) at days 0 and 5 into the left gastrocnemius muscle. Control rats received identical injections of physiological saline (pH 7.2) on the same schedule. Two acidic saline rats were given DSW from 1 week following the last IM injection to sacrifice. All rats were sacrificed on day 20. All regions of interest were examined for the changes of pain-related neurotransmitters with immunohistochemistry. RESULTS: Preliminary results showed that compared to controls, acid injected rats demonstrated strong expression of serotonin in red and raphe nucleus. Acid injected rats showed significant reductions of the serotonin expression in red and raphe nucleus after DSW drinking. CONCLUSION: IM acid injections increased the expression of serotonin in red and raphe nucleus of rats. The overwhelming reduction of serotonin expression in the nuclei after DSW drinking suggests DSW might be helpful for pain and anxiety. These preliminary data support the validity of acidic saline treatment as a model of FM, and provide a foundation for future analyses of specific brain regions that contribute to this syndrome.

The Effect of Yacon (Smallanthus sonchifolius) Extract against Dibutyltin Dichloride-induced Pancreatitis / 대한해부학회지

Yacon is used in folk medicines as a medicinal tea for hypoglycemia. In a recent study described herein, anti-oxidative, -bacterial, -fungal activities and cell protective functions of leaf extract of Smallanthus sonchifolius have been reported. In this study, to evaluate the effect on pancreatitis by using yacon extract (YE), we examined the efficacy of YE on DBTC (8 mg/kg)-induced pancreatitis in rats. After the treatment of DBTC on day 21, highly increased inflammatory cells, necrosis of acinar cells and connective tissues were observed. However, the inflammation was strongly inhibited in YE as compared to control group (CON). As a result of immunoreactions against HSP27, HSP70 and MAC387, weak or no possibilities of normal group (NOR) were observed in pancreas, whereas in immunoreactions against HSP27 and HSP70, strong expression of CON was observed in acinar and duct cells on day 14. However, the expression of HSP27 was decreased in acinar cells for CON treatment on day 21 as compared to 14 days observation, whereas strong expression of HSP27 was observed in duct cells and blood vessels on day 21. As regards the immunoreactions against HSP70, weak or no possibilities of CON were observed in duct cells and blood vessels as well as in acinar cells on day 21. In CON, time-dependent increase of MAC387 was observed. However, the expressions of HSP27 and HSP70 were weakly observed in YE as compared to CON on day 14 with strong positive reaction in acinar cells on day 21. Immunoreactions against MAC387 were decreased in YE on day 14 than day 7, which increased on day 21 as compared to day 14. These results suggested that yacon extract has inhibitory and mitigatory effects against DBTC-induced pancreatitis.

The Neuroprotective Effects of Woohwangcheongsim-won on Cerebral Ischemia following the Middle Cerebral Artery Occlusion in Rats / 대한해부학회지

The purpose of this study is to evaluate the effects of Woohwangcheongsim-won on reperfusion following the MCA occlusion in rats. To evaluate the effect of Woohwangcheongsim-won on reperfusion following the MCA occlusion, the volume of cerebral ischemia and edema was measured. The volume of the control group, which was ischemic-damaged was 23.6%, and that of the sample group was 13.5%. The voluminal ratio of the right/left hemisphere was 116 in the control group, and that of the sample group was 107.

Fine Structure of Goblet Cell Regeneration on Experimental Colitis Induced by Dextran Sulfate Sodium / 대한해부학회지

Ulcerative colitis is recognized as important causes of gastrointestinal diseases in children and adults. I observed the fine structural changes of goblet cell regeneration after experimental ulcerative colitis induced by dextran sulfate sodium (DSS) in rats. Experimental colitis was induced with 5% DSS in the drinking water for 5 days, and the healing groups were fed with pure water for 7 days thereafter. In the early stage of goblet cell regeneration (repair 3 days group), granular endoplasmic reticulums were developed around the nucleus, and some mucigen granules were observed around the nucleus. In the middle stage of goblet cell regeneration (repair 5 days group), Golgi complexes were well developed in the upper region to the nucleus, and many mucous granules were observed. In the matured goblet cell regeneration (repair 7 days group), many mucous granules appeared in the upper region of the cell, and cell organelles were located in the base and periphery of the cell. These results suggest that the goblet cell was completely reconstructed within 7 days after ulcerative colitis.

A Study of Immunohistochemical Change of the Experimental Ulcerative Colitis induced by DSS / 대한해부학회지

The experimental ulcerative colitis is chronic inflammatory illness in colon, which didn't reveal the exact reason and pathophysiological situation. In this study, the colitis was induced by 3% DSS (mw; 40,000) for 5 days in mouse which was resemble to inflammatory bowel disease in human, and immunohistochemical changes were observed in the mucosa. In inflammatory group, thickness of the colon was increased and the length of colon was shorter than that of the normal group and the body weight decreased. In microscopic aspect, the crypt erosion, many inflammatory cells and submucosal edema were occurred. In immunohistochemical study, the immunity of COX1 in the inflammatory group was not changed to comparing the normal group, but COX2 immunoreactivity was increased than the normal group, HSP70 immunoreactivity were also increased than the normal group. MAC387 which used to detect the macrophage was increased than the normal group and PCNA immunoreactivity were increased along to the mucal layer. And the number of apoptosis cells detected by TUNEL was increased. In these results, the experimental colitis revealed the tissue defense mechanism as well as inflammatory system and observed the stuffs related to the regeneration.

Histological Study of Experimental Colitis Induced by Dextran Sulfate Sodium / 대한해부학회지

Inflamatory bowel disease is the general medical terminology on chronic inflammatory illness of unknown origin, but it is considered that environmental, genetical, immunological factors may develop this chronic disease. I examined the histological changes on the experimental ulcerative colitis induced by dextran sulfate sodium(DSS) in rats. Experimental colitis was induced with 5% DSS in the drinking water for 5days in rats (experimental group). And the repair group were treated with 5% DSS for 5days and with pure water after 7days in rats. In experimental group, there are many inflammatory finding in colon of rat which contained loss of body weight, crypt erosion, recruitment of inflammatory cells, submucosal edema. In repair group, the inflammation was recovered that the body weight was incerased, the crypt was recovered. And Ki 67 immunoreaction were restricted lower 1/3 crypt in normal group but positive Ki 67 reaction appeared in the repaired all region. In this study, DSS was induced experimental colitis and the colitis was repaired when we stoped DSS supply. And the Ki 67 during repaired period were overproduction.

A TUNEL and Electron Microscopic Study on the Delayed Neuronal Death of Rat CA1 Pyramidal Neurons after MCAO / 대한해부학회지

Neurons are very sensitive to various injuries such as ischemia, hypoxia, hypoglycemia, etc. Frequently, the hippocampal CA1 area has been used as a region for studying ischemic delayed neuronal death, which is induced by middle cerebral artery occlusion (MCAO). However, it is still controversial whether the delayed neuronal death is necrotic or apoptotic. In this study, we investigated the neuronal death in hippocampal CA1 areas by TUNEL stain and electron microscopic observation using a rat MCAO and reperfusion model. RESULTS: 1. The TUNEL positive reaction occurred only within the CA1 area ipsilateral to MCAO. 2. In EM images, many features that imply necrosis were found in the CA1 pyramidal neurons ipsilateral to MCAO. These results indicate that both necrotic and apoptotic features coexist in the delayed neuronal death of the hippocampal CA1 area after MCAO.

he Changes of the Basilar Artery Following Experimental Cerebral Subarachnoidal Hemorrhage / 대한해부학회지

The cerebral artery spasm is a phenomenon frequently present in cases of subarachnoid hemorrhage (SAH). Previous reports indicated that vasospasm could be produced primarily by muscle contraction and constricted vessels that exhibit myonecrosis and subendothelial changes. Pharmacological studies have shown that vasospastic arteries decrease in contractility but increase the spontaneous tone and stiffness compared to normal cerebral arteries. We carried out electron microscopic to observe the morphological changes of the basilar artery following the experimental SAH. We examined changes in the size of the lumen and thickness of the basilar artery in SAH. Morphological changes of cerebral basilar artery following SAH : (1) The size of the lumen of basilar artery decreased about 47%, while its thickness increased about 170%. (2) The shape of the endothelial cell transformed to a cuboidal type and its thickness increased, while the length of the smooth muscle cell shortened and the thickness increased.

Effects of the Occlusion of Middle Cerebral Artery on the Pyramidal Cells of the Hippocampal Formation / 대한해부학회지

In order to study damages on brain cells upon occlusion and reperfusion, brain infarction was induced by insertion of a single nylon thread, through the internal carotid artery, into a middle cerebral artery. After occlusion of 1 hr and reperfusion for variable duration, brain slices were used to observe changes in the brain morphology and in the pyramidal neurons of the himppocampal formation. In this study we found following results. 1) The operation took 20~30 min and about 30% of the operated animals were suitable for studying neurological aspects. 2) The TTC stain showed that about 23.9% of the total brain area was damaged in the 72 hr-reperfusioned sample. 3) The degree of brain edema was larger in the left hemisphere (damaged side) than in the right one (contralateral undamaged side). 4) Pyramidal cells of the damaged hippocampal formation showed features of necrosis such as shrinkage, large vacuole, swelling, and cell debris. 5) The numbers of survived cells per mm2 of the hippocampal formation were 93 in the undamaged animal, and 23 and 3 in the 3 and 7 days after reperfusion, respectively.

Changes of neuropeptides immunoreactivity according to dehydration in paraventricular nuclei / 대한해부학회지

Dehydration induced an increase in plasma osmotic pressure that causes the release of the neurohypophysial hormone (Vasopresin, Oxytocin) which are synthesized in neurons of the paraventricular (PVN) and supra optic (SON) nuclei in the hypothalamus. On the other hand, PVN which plays an important role as an integration site for the neuroendocrine and autonomic nervous system neurons responded to osmotic stimulation. In this experiment, we studied that the change of several neuropeptidies (AVP: arginine vasopressin, CRF: cor-ticotrophin releasing factor, GAL: galanin, NT: neurotensin. NPY: neuropeptide Y) immunoreactivity in the PVN according to the dehydration. The body weight of the rats decreased during dehydration and various changes were detected in hypothalamic neuropeptidies immunoreactivity.Our results show that: 1. Dehydration significantly increased AVP, CRF and GAL immunoreactivity in the PVN. 2. Dehydration slowly decreased NT immunoreactivity in the PVN. 3. NPY immunoreactive cell bodys were appeared during dehydration which did not observed in PVN at normal group.

The Effects of Korean Medical Drug on Lymphocyte Activity in Allergic Contact Dermatitis / 대한면역학회지

The purpose of this study was to elucidate the effects of Hwangyun, Hwangyunhaedogtang, and Kumeunhwa on the lymphocyte activity in allergic contact dermatitis induced by contact allergen 1-chloro-2,4-dinitrobenzene (DNCB) of Balb/c mouse. For examination of a contact hypersensitivity, MEST (mouse ear swelling test) and lymphocyte proliferation assay measured by [(3)H]-methylthymidine incorporation were done. Cytokine mRNA in the draining lymph node cells were examined by RT-PCR. Contact hypersensitivity was more effectively induced by 0.25% DNCB treatment than 1% DNCB treatment. Local lymph node cell proliferation from DNCB-sensitized mouse was most highly elicitated with 100 ug/ml DNBS stimulation in vitro. The cytokine profiles of lymph node cells from DNCB-sensitized and DNBS-stimulated mouse were strong expression of IL-2 and IFN-r, weak expression of LT and IL-4, and no expression of IL-6 and IL-10. This lymphocyte proliferation was significantly inhibited in mice administered Korean medical drug for 10 days and sensitized with DNCB at day 5 (88.22%, 65.14%, and 52.29% in Hwangyun, Hwangyunhaedogtang, and Kumeunhwa, respectively). But Kumeunhwa was not effective in the inhibition of lymphocyte proliferation when administered after DNCB-sensitization. The cytokine expressions were also inhibited especially IL-2 and IFN-r in Hwangyun administered- mice. These inhibitions of lymphocyte activity by Korean medical drugs were also observed when stimulated with ConA (1 ug/ml). Conclusively, immune responses of contact hypersensitivity induced by DNCB are involved in local lymph node T cells mainly Th1 type cells, and Korean medical drugs especially Hwangyun suppressed allergic contact dermatitis via inhibition of the activity of these cells.