Valproic acid inhibits the expressions of MMP-9 and AQP-4 proteins in the brain tissue of rats with traumatic brain injury / 医学研究生学报

Objective Few studies are reported on the protective effect of valproic acid (VPA) against traumatic brain injury (TBI) by down-regulating the protein expressions of matrix metalloproteinase-9 (MMP-9) and aquaporin-4 (AQP-4) in the brain tissue. This study aimed to investigate the neuroprotective effects of different doses of VPA against TBI in experimental rats. Methods We randomly divided 100 adult male rats into five groups of equal number, sham operation, TBI model, and low- (30 mg), medium- (150 mg) and high-dose (300 mg) VPA treatment. At 1, 3, 7 and 14 days after modeling by controlled cortex impact, we obtained the modified Neurological Severity Scores (mNSS), measured the VPA concentration in the venous blood, and then killed the rats and harvested the brain tissue for determination of the water content using the dry-wet method and the expressions of MMP-9 and AQP-4 by Western blot and immunohistochemistry. Results At 1, 3, 7 and 14 days after modeling, the mNSSs in the high-dose VPA group were 4.6 ± 1.3, 3.8 ± 1.3, 3.0 ± 0.7 and 1.8 ± 0.8, respectively, significantly lower than 8.4 ± 0.9, 7.0 ± 0.7, 5.8 ± 1.0 and 4.5 ± 1.3 in the TBI group (P < 0.05), decreasing in a time-dependent manner, with statistically significant difference between any two dose groups (P < 0.05). At 1, 3 and 7 days, the water contents in the brain tissue were (76.2 ± 0.7)%, (76.9 ± 1.7)% and (73.9 ± 1.3)% in the high-dose VPA group, significantly lower than (79.6 ± 0.8)%, (82.6 ± 0.8)% and (78.6 ± 0.7)% in the TBI group (P < 0.05), also decreasing in a time-dependent manner, with statistically significant difference between any two dose groups (P < 0.05). At 1 and 3 days, the expressions of MMP-9 and AQP-4 in the brain tissue were markedly down-regulated in the VPA groups in a dose-dependent manner as compared with those in the TBI group (P < 0.05), with statistically significant difference between any two dose groups (P < 0.05), and meanwhile immunohistochemistry showed large numbers of cells with positive expressions of MMP-9 and AQP-4, which were reduced with the increased dose of VPA. Conclusion VPA has a neuroprotective effect against TBI in rats by inhibiting the expressions of MMP-9 and AQP-4 proteins in the brain tissue and alleviating brain edema. Within the range of the doses studied, higher-dose VPA produces a better effect.

Protective effects and mechanism of Naoxintong Capsules on rat brain microvascular endothelial cells (rBMECs) induced by oxygen-glucose deprivation / 中草药

Objective: To investigate the protective effects and mechanism of Naoxintong Capsules (NXT) on primary cultured neonate rat brain microvascular endothelial cells (rBMECs) induced by oxygen-glucose deprivation. Methods: The primary cultured rBMECs model was established and the identification of rabbit anti-rat VIII factor was carried out. MTT was used to screen out the concentration range of NXT intestinal absorption solution to pretect rBMEC in vitro, three doses were selected for experiment. The experimental groups were divided into control group, model group, nimodipine group (200 μg/mL, NXT intestinal absorption solution group (62.50 mg/L, 125.00 mg/L, and 250.00 mg/L), and NXT intestinal absorption solution (250.00 mg/L) and LY294002 (20 μmol/L, PI3K/Akt pathway inhibitor) co-administration group. The morphology of rBMECs was observed under inverted microscope. The expression of lactate dehydrogenase (LDH) and matrix metalloproteinase 9 (MMP-9) in the cell supernatant was detected by ELISA kit. The apoptosis was observed by Hoechst33342 staining fluorescence microscope. The early apoptotic rate of rBMECs in each group was detected by FCM, and the expression of PI3K/Akt signaling pathway key proteins was detected by Western blotting. Results: Compared with model group, the administration of NXT could significantly improve the morphology of rBMECs, decrease the intracellular levels of LDH and MMP-9, significantly reduce the number of apoptotic cells and early apoptotic rate of rBMECs, and inhibit the expression of p-Akt, Bcl-2 upregulation, decrease the expression of Bax, and inhibit caspase-3 activity. The addition of LY294002, a specific inhibitor of PI3K/Akt signaling pathway, blocked the signal transduction of this pathway and significantly reduced the protective effect of NXT. Conclusion: NXT have protective effects on rBMECs induced by oxygen-glucose deprivation, and its mechanism is related to the PI3K/Akt signaling pathway.

Optical coherence tomography imaging of the basal ganglia: feasibility and brief review

Optical coherence tomography (OCT) is a promising medical imaging technique that uses light to capture real-time cross-sectional images from biological tissues in micrometer resolution. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in cardiology and ophthalmology. Application of this technology in the brain may enable distinction between white matter and gray matter, and obtainment of detailed images from within the encephalon. We present, herein, the in vivo implementation of OCT imaging in the rat brain striatum. For this, two male 60-day-old rats (Rattus norvegicus, Albinus variation, Wistar) were stereotactically implanted with guide cannulas into the striatum to guide a 2.7-French diameter high-definition OCT imaging catheter (Dragonfly™, St. Jude Medical, USA). Obtained images were compared with corresponding histologically stained sections to collect imaging samples. A brief analysis of OCT technology and its current applications is also reported, as well as intra-cerebral OCT feasibility on brain mapping during neurosurgical procedures.

Pharmacokinetics and brain distribution differences of baicalin in rat underlying the effect of Panax notoginsenosides after intravenous administration / 中国天然药物

Baicalin (BA) is the most well-known flavonoid present in Radix Scutellariae. The aim of this study was to explore whether the pharmacokinetic behavior of BA in rat brain can be affected by Panax notoginsenosides (PNS), and to assess the possible mechanism for the observed effects. Specific HPLC and HPLC/MS/MS methods were developed and validated for the determination of BA in the rat plasma and brain using carbamazepine as an internal standard. BA was found to enter rat brain quickly after a single intravenous dose. When co-administered with PNS, clearance (CL) of BA from rat plasma decreased by 50.00%, while the area under the curve AUC0-t and AUC0-∞ increased 94.69% and 87.68%, respectively. On the other hand, some pharmacokinetic parameters of BA in rat brain had obvious differences after PNS was administered, such as an increase in Tmax from 5 min to 15 min, an increase in AUC0-t and AUC0-∞ by 42.75% and 29.39%, respectively, as well as a decrease in CL by 27.95%. Together, these results indicate that PNS can decrease the elimination rate of BA from rat plasma, promote the penetration of BA into rat brain, increase the concentration and slow down the elimination of BA from rat brain. The data provide important information that compatibility with PNS can promote the consequent effects of BA for the treatment of encephalopathy.

Impacto de la separación materna durante la lactancia sobre el tamaño del cerebro y la inmunorreacción al receptor Gaba ­ A / Impact of maternal separation during nursing on brain size and onGABA-Areceptorimmunoreactivity

Introducción. El vínculo materno es fundamental para el establecimiento y mantenimiento de las redes sinápticas, y el desarrollo morfofisiológico y emocional de los individuos. Los niños maltratados o rechazados son más propensos a desarrollar psicopatologías. Los modelos animales permiten una aproximación experimental a mecanismos involucrados en alteraciones ocasionadas por estrés temprano. Objetivo. Determinar si la separación materna durante la lactancia, afecta en el adulto el tamaño del cerebro y el número de células inmunorreactivas a la subunidad alfa 1 del recep-tor ácido gamma-aminobutírico: GABA-A. Métodos. Se mantuvieron ratas Wistar con ciclo invertido luz-oscuridad, sin restricciones de agua o comida. Durante la lactancia, a unas mamás les fueron separadas las crías dos veces al día y otras se mantuvieron como grupo control. El día 22 los sujetos se separaron por sexo y tratamiento. El día 60 se perfundieron con paraformaldehído, previa anestesia, y los cere-bros fueron extraídos y pesados. Para identificar el tamaño cerebral, se hicieron cinco cortes seriados de 20 µm cada 100 µm. Se tomaron fotografías y se utilizó una escala micrométrica. La inmunorreacción al receptor GABA-A se analizó en cortes de 20 µm mediante tinción por inmunohistoquímica. Resultados. En las ratas adultas, el peso cerebral total de las ratas separadas fue menor. En las hembras separadas se observó reducción estadísticamente significativa en el tamaño del hipocampo. En los machos separados se observó disminución de la marcación para la subunidad alfa1 del receptor GABA-A, en la corteza prefrontal, la amígdala y el hipocampo. Conclusiones. Estos resultados muestran que la separación materna durante la lactancia altera, en ciertas áreas cerebrales del adulto, el tamaño y la inmunorreacción al receptor GABA-A, y que estos cambios son diferentes en hembras y machos

Introduction: The maternal bond is crucial to establish and maintain synaptic networks and for morphophysiological and emotional development of individuals. Neglected or abused kids are more susceptible to develop psychopathologies. Animal models allow an experimen-tal approach to mechanisms involved in alterations due early stress. Objective:To determine if maternal separation during nursing alters brain size in adults and the amount of immunoreactive cells to alpha subunit of GABA-A receptor. Methods: Wistar rats were kept under reverse light-dark cycle with food and water ad libitum. During nursing, pups were separated from their mothers twice a day and other group was used as control. At day 22nd, subjects were separated by gender and treatment. In day 60, subjects were anesthetized and perfused with paraformaldehyde and brains were extracted and weighted. In order to identify brain size, 5 serial slides of 20 µm were made every 100 µm. Pictures were taken and micrometric scale was used. Immunoreactivity to alpha subunit of GABA-A receptor was analyzed in 20 µm slides through immunohistochemistry. Results: In adults, total brain weight of separated rats was inferior thanin the control group. Separated females showed a significant reduction of hippocampus size. In separated males a decrease of immunoreactivity to GABA-A receptor in prefrontal cortex, amygdala and hip-pocampuswas evidenced. Conclusions: These results show that maternal separation during nursing alterssize in some brain areas of adult rats, the immunoreactivity to alpha subunit of GABA-A receptor, and these changes are different between separated females and males.

Effects of fluoride and ethanol administration on lipid peroxidation systems in rat brain.

Exposure to fluoride and excessive ethanol consumption has been identified as a serious public health problem in many parts of the world, including India. Thus, the effect of co-exposure to fluoride and ethanol for 3-6 weeks was studied on lipid peroxidation (LPO) and oxidative stress related parameters in the rat brain. After 3 weeks, co-treated animals showed 95% increase in LPO levels compared to control. However, the levels of reduced glutathione, total and protein thiols were decreased. These changes were accompanied by a decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase. Rats exposed to fluoride together with ethanol for 6 weeks resulted in 130% increase in LPO and decrease in the reduced glutathione levels. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase were reduced under these conditions. Brain histology revealed excessive lymphocytes, edema and spongeosis in the cortical region after six weeks of fluoride and ethanol treatment. These results suggest that exposure to fluoride together with ethanol enhances lipid peroxidation by affecting antioxidant defence systems in the rat brain.

Protection of Danhong Injection on brain microvascular endothelial cells injury by hypoxia in neonate rats / 中草药

Objective: To study the protective effect of Danhong Injection (DI) on primary cultured neonate rat brain microvascular endothelial cells (rBMECs) injury. Methods: The primary cultured rBMEC model was established and the identification of rabbit anti rat VIII factor was carried out. The cells were divided into control, model, low-, mid-, and high-dose (25, 50, and 100 μL/mL) DI groups in hypoxic condition for 4 h after administration. The cell morphology was observed under microscope, the apoptosis rate and DNA content were determined by flow cytometry, and the lactate dehydrogenase (LDH) level in cultural supernatants and cell superoxide dismutase (SOD) activity were detected according to the kit methods. Results: DI (50 and 100 μL/mL) could alleviate the rBMEC damage induced by hypoxia remarkably, improve the cell morphology of rBMECs, decrease the apoptosis significantly, inhibit the blockage of rBMECs in G1/S phase and the leakage of LDH, and increase the SOD activity. Conclusion: DI plays a significant role in the protection on injured primary cultured rBMECs induced by hypoxia, and the mechanism may be related to the enhancement of cellular anti-oxidative capacity and the inhibition of apoptosis.

Functional activity of the cannabinoid 1 receptor is not affected by opioid antagonists in the rat brain / 대한마취과학회지

BACKGROUND: WIN55212-2 is a synthetic cannabinoid agonist and selective to cannabinoid 1 (CB1) receptors, which are distributed mainly in the central nervous system. Opioid receptors and CB1 receptors have several similarities in terms of their intracellular signal transduction mechanisms, distributions, and pharmacological action. Several studies have therefore sought to describe the functional interactions between opioids and cannabinoids at the cellular and behavioral levels. The present study investigated agonist-stimulated [35S]GTPgammaS binding by WIN55212-2 in rat brain membranes and determined the antagonism by selective opioid antagonists at the level of receptor-ligand interaction and intracellular signal transduction. METHODS: Sprague-Dawley rats (male, n = 20) were euthanized for the preparation of brain membranes. In agonist-stimulated [35S]GTPgammaS binding by WIN55212-2, the values of EC50 and maximum stimulation (% over basal) were determined in the absence or presence of the micro, kappa and delta opioid receptor antagonists naloxone (20 nM), norbinaltorphimine (3 nM), and naltrindole (3 nM), respectively. Ke values for opioid antagonist inhibition in the absence or presence of each opioid receptor antagonist were calculated using the following equation: [nanomolar antagonist] / (dose ratio of EC50 - 1). RESULTS: In WIN55212-2-stimulated [35S]GTPgammaS binding in the rat brain membranes, the values of EC50 and maximum stimulation (% over basal) were 154 +/- 39.5 nM and 27.6 +/- 5.3% over basal, respectively. Addition of selective opioid antagonists did not produce a significant rightward shift in the WIN55212-2 concentration-response curve, and Ke values were not applicable. CONCLUSIONS: Our results suggest that the functional activity of WIN55212-2-stimulated [35S]GTPgammaS binding was not affected by opioid antagonists in the rat brain membranes. Although the exact mechanism remains unclear, our results may partially elucidate their actions.

Non-genomic effect of L-triiodothyronine on calmodulin-dependent synaptosomal protein phosphorylation in adult rat cerebral cortex.

The present study was undertaken to examine calmodulin-dependent effect of thyroid hormones (THs) on synaptosomal protein phosphorylation in mature rat brain. Effect of L-triiodothyronine (L-T3) on in vitro protein phosphorylation was measured in a hypotonic lysate of synaptosomes prepared from adult male rat cerebral cortex, incubated in presence and absence of calcium ion (Ca2+) and calmodulin. L-T3 significantly enhanced incorporation of 32P into synaptosomal proteins as compared to basal level of phosphorylation in the presence of Ca2+ and calmodulin. Under these conditions, increase in protein phosphorylation was 47, 74 and 52% for 10 nM, 100 nM and 1 M L-T3, respectively. Chelation of Ca2+ using ethylene glycol-bis (2‑aminoethylether)-N, N, N’, N’-tetraacetic acid (EGTA) inhibited the effects of Ca2+/calmodulin on TH-stimulated protein phosphorylation levels. This study suggests that a high proportion of L-T3-stimulated protein phosphorylation involves Ca2+/calmodulin-dependent pathways in adult rat cerebrocortical synaptosomes.

Effect of Traumatic Brain Injury on Expressions of Glial Cell Line-derived Neurotrophic Factor in Brain Tissue of Rats / 中国康复理论与实践

@#ObjectiveTo investigate the effect of traumatic brain injury on the expressions of glial cell line-derived neurotrophic factor(GDNF) in brain tissue of rats.MethodsMale Sprague-Dawley rats were divided into normal control, sham surgery and injury groups. The rats of injury groups were subjected to Marmarou's closed traumatic brain injury and then were subdivided into 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h and 5 d subgroups according to the time elapsed after injury. The expressions of GDNF were studied with immunohistochemistry.ResultsIn control group, mild expressions of GDNF were observed in cortex, hippocampus and brain stem of rats. The number of GDNF positive neurons reached the peak level at 2 h in cortex after injury, and lasted for 5 d. In hippocampus and brain stem, the number of that also reached the peak level at 2 h, and lasted for 72 h.ConclusionThe expressions of GDNF increased significantly at the early time in cortex, hippocampus and brain stem of rats after injury. The significant expression of GDNF lasted longer in cortex.

Lomerizine inhibited the function of P-glycoprotein(P-gp) without decreasing the expression of mdr1 gene and P-gp in primarily cultured rat brain microvessel endothelial cells / 中国临床药理学与治疗学

AIM: To study the effect of Lomerizine on the activity of P-glycorprotein (P-gp) in primary cultured rat brain microvessel endothelial cells (RBMECs). METHODS: Flow cytometry was used to study the efflux of rhodamine123 (Rh123) and expression of P-gp in RBMECs. RT-PCR was used to measure the expression in mRNA level of mdr1 gene in RBMECs. Transwell model was used to detect the influence of Lomerizine on the transport of Rh123 through RBMECs monolayer. RESULTS: Lomerizine inhibited the efflux of Rh123 in RBMECs. No changes of P-gp and mdr1 gene mRNA expression were detected in RBMECs after the treatment with 30 μmol·L-1 Lomerizine for 72 h. In the study of Transwell model, Lomerizine increased significantly the transport of Rh123 through RBMECs monolayer from upper compartments to lower compartments, and inhibited obviously the transport in reverse direction. CONCLUTION: The effect of Lomerizine on the activity of P-gp was mainly via its direct inhibitory effect on the function of P-gp in RBMECs and the transport of P-gp substrates in BBB may be affected by lomerizine.

Effect of Maternal Thyroxine Treatment on the Postnatal Development of Brain-derived Neurotrophic Factor-containing Neuron in the Brain of Pups of Alcohol Abused Mother / 대한해부학회지

Maternal alcohol abuse is thought to be the common cause of mental retardation. Especially, continuous alcohol consumption during critical period of brain development induce fetal alcohol effects. In this study, the authors investigated the effects of maternal alcohol drinking on the postnatal changes of BDNF contents and patterns of BDNF-containing neuron in neonatal rat brain, and, the influence of maternal thyroxine treatment on the brain of pups of alcohol abused mother. Pregnant rats were divided into three groups. Alcohol-fed group (n=4) received 35 calories of liquid alcohol diet daily from gestation day 6; control pair-fed group (n=4) was fed a liquid diet in dextrin replaced alcohol isocalorically; alcohol+T4 group (n=4) received 35 calories liquid alcohol diet and exogenous thyroxine (5 microgram/kg/day) subcutaneously. The amount of BDNF was significantly higher in the alcohol+T4 group as compared to the alcohol group at P7, P14 and P21, especially, alcohol+T4-exposed pups showed a significant increase of BDNF at P7. The decrease in BDNF was found in alcohol group compared to control pair-fed group at all ages. In alcohol+T4 group, BDNF-containing Purkinje cells exhibited mature pattern and monolayer arrangement at P14. Alcohol+T4 group showed mature pattern and numerical increase of BDNF-containing cells in cerebral cortex, hypothalamus and hippocampus at P7. The BDNF immunoreactivity of hippocampus continued to show prominent configuration in alcohol+T4 group at P28. These results indicate that the increase of the BDNF-containing neurons and BDNF amount in pups of thyroxinesupplemented alcohol-exposed dams as compared to control pair-fed and alcohol-exposed pups at P7, presumably suggest the early postnatal growth stimulatory effect of the exogenously supplemented thyroxine. Therefore, the increase of BDNF synthesis caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects, one of the ill effects as a result of the dysthyroid state following maternal alcohol abuse.

Biochemical toxicity study on rat brain upon co-exposure to aluminium and ethanol.

Aluminium and alcohol are well known neuro toxins. Co-exposure of these neuro toxins has been studied in rats. Alcohol exposure significantly affected the aluminium content, protein content, acid phosphatase activity, alkaline phosphatase activity, alanine aminotransferase activity, glutathione-S-transferase activity, and glucose 6-phosphate dehy-drogenase activity of brain. Aluminium exposure, on the other hand, contributed significantly only in the alterations of aluminium content, acid phosphatase activity, and aspartate aminotransf erase activity of brain of rats in the present study. The interaction of both aluminium intoxication and alcohol exposure is significant only in the case of acid phosphatase and glutathione-S-transferase activities of brain. Therefore, from the observations of the present investigation, it can be suggested that the general neurotoxic-ity produced by aluminium is not modified by alcohol. However, the aluminium load and oxidative stress, caused by aluminium exposure, may be influenced by alcohol co-exposure.

Hydroxyl Radical Production after Intrastriatal Injection of Dopamine and the Effect of Growth Hormone on the Apoptosis of Striatal Neurons Injured by Hypoxia-ischemia in Newborn Rat Brain / 대한소아내분비학회지

PURPOSE:We investigated the production of oxygen hydroxyl radicals in the striatum of neonatal rat brain after intrastriatal injection of dopamine (DA) and the effect of growth hormone (GH) on the apoptosis of striatal neurons injured by hypoxia-ischemia. METHODS:The extracellular striatal levels of 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA as indicators of hydroxyl radical(OH-) production were measured by in vivo microdialysis in the striatums of 7 day-old newborn rats (n=10) after direct intrastriatal infusion of dopamine hydrochloride (1.0 micromol/microL). The samples of perfused artificial cerebrospinal fluid (CSF) were collected every 10 minutes interval. The levels of DA, 2,3-DHBA and 2,5-DHBA of CSF were analysed by HPLC (high performance liquid chromatography). Also, the brains were removed at 24 hour after hypoxic-ischemic injury by Rice-Vannucci method. The coronal sections (12 micrometer) of paraffin-fixed brains were stained by TUNEL (terminal transferase-mediated dUTP nick-end-labelling) technique, and the neuronal cells undergoing apoptosis in the striatum were observed by fluorescent microscopy and compared between GH-treated (50 mg/kg, Dong-Ah Pharmacy Co.) and saline-treated rats. RESULTS:The extracellualr striatal levels of 2,3-DHBA and 2,5-DHBA increased abruptly in the first 10 minutes samples after intrastriatal injection of DA. After then, the levels declined slowely. The levels of striatal extracelluar 2.3-DHBA increased up to 621.8+/-508.7% of basal levels (P<0.05), and the levels of 2.5-DHBA increased up to 262.8+/-198.1% of basal levels (P<0.05). GH reduced markedly the number of apoptotic neuronal cells in the striatum after hypoxic-ischemic brain injury. CONCLUSION: The level of hydroxyl radicals increased abruptly after intrastriatal injection of DA and GH reduced markedly the number of apoptotic neuronal cells in the striatum after hypoxic-ischemic brain injury.

Age-Related Changes of MHC Class II-immunoreactive Dendritic Cells in Rat Brain / 대한소아신경학회지

PURPOSE: Dendritic cells are antigen presenting cells(APC) that express class II major histocompatibility complex gene products on their surface. Recently, it was proved that dendritic cells activate antitumor immunity for intracranial germ cell tumor. The aim of the present study is to investigate the age-related changes of MHC class II-immunoreactive dendritic cells in the rat brain. METHODS: Male rats(Sprague-Dawley) were sacrificed at 1 month, 12 months and 24 months after birth. Brains were removed and sliced in rat brain matrix. Brain slices were cryosectioned coronally at interaural 5.70-6.70 mm. Brain tissue sections were immunohistochemically reacted with monoclonal MHC class II antibody. RESULTS: MHC class II-immunoreactive dendritic cells were observed in choroid plexuses and white matter(corpus callosum, cerebral peduncle and external capsule). The number of MHC class II-immunoreactive dendritic cells was slightly increased with age. As age increases, shapes of MHC class II-immunoreactive dendritic cells became more complex and aggregated together. CONCLUSION: As age increases, MHC class II-immunoreactive dendritic cells in choroid plexuses and white matter of the brain became not only more complex in shape, but also increased in number to improve immunity.

Expression Changes of c-Fos Protein of Rat Brain Following Pentylenetetrazol-induced Seizures / 대한소아신경학회지

PURPOSE: The expression of c-Fos protein has been shown to be a useful marker for elevated levels of neuronal activity generated in the brain following different stimuli, including seizures. This study was conducted to investigate distribution and numbers of neurons where dentate and cingulate gyrus become activated following pentylenetetrazol-induced seizures by means of expression patterns of c-Fos protein. METHODS: Rats were sacrificed at increasing times(1 hour, 2 hours, 8 hours, 1 day, 4 days and 7 days) after pentylenetetrazol-induced seizure. Rat brains were removed and sliced in rat brain matrix. Brain slices were coronal sectioned at interaural 5.70-6.70mm. Serial sections were immunohistochemically reacted with polyclonal c-Fos antibody. The distribution and numbers of c-Fos protein immunoreactive neurons in dentate gyrus and cingulate gyrus were examined and analyzed statistically with Mann-Whitney U test. RESULTS: The numbers of c-Fos protein immunoreactive neurons in dentate gyrus peaked at 1 hours and reached almost normal conditions at 7 days after seizure. Also, same patterns were occurred in cingulate gyrus. Concentration value that pentylenetetrazol can induce was different from each animals and c-Fos immunoreactive cells were various kinds of neurons. CONCLUSION: Higher numbers of c-Fos protein immunoreactive neurons were found in dentate and cingulate gyrus at the same times after seizure. These findings suggest that neurons of dentate and cingulate gyrus play a crucial role in seizure onset following pentylenetetrazol-induced seizure.

Effects of c -Fos Immunoreactivity on Central Nervous System after Administration of Aspirin / 체질인류학회지

Aspirin is one of the popular non -steroid anti -inflammatory drugs used in the management of pain. This study was performed to investigate the effects of aspirin on c -Fos expression in rat CNS after inducing somatic pain with formalin. Male S.D. rats were injected subcutaneously with 0.1 ml of 5% formalin in the plantar surface of right hindpaw. For experimental group, aspirin was administered orally before injection of formalin. Asprin -untreated group was utilized as the control group. Rats were sacrificed at 0.5, 1, 2, 6 and 24 hours after formalin injection. Rat brains were removed and sliced in rat brain matrix. Brain slices were coronally sectioned at interaural 5.70 ~6.70 mm. Serial sections were immunohisto-chemically reacted with polyclonal c -Fos antibody. The numbers of c -Fos protein immunoreactive neurons in the cingulate cortex, primary somatosensory area, and hippocampus were counted and analyzed statistically with Mann - Whitney U test. Results were as follows: 1. Higher numbers of c -Fos immunoreactive neurons were found in the cingulate cortex, primary somatosensory area and hippocampus. 2. Both aspirin -treated and -untreated groups, numbers of c -Fos immunoreactive neurons were significantly higher all time points than formalin -untreated group, which peacked at 2 hours. 3. The numbers of c -Fos immunoreactive neuron of the aspirin -treated group were less compared to the aspirin - untreated group at each time point. In conclusion, these results provide some basic knowledge in understanding the mechanism and control of formalin - induced somatic pain.

The Effects of Cyclosporin A on the Signal Transduction System in the Rat Brain / 대한정신약물학회지

The most important molecular mechanisms of intraneuronal signal transduction are those mediated by calcium and reversible protein phosphorylation. Although many studies pursued the activation of the protein kinases in the nervous system, there are only few reports focused on the protein phosphatases. In this article, the authors report the effects of cyclosporin A (CSA), an inhibitor of calcineurin, on the calcium signaling-related molecules such as ERKs, calmodulin-dependent kinase II (CaMKII) and CREB in the rat hippocampus. The authors also report the effects of cyclosporin A on the electroconvulsive shock (ECS)-induced seizure and the activation of ERKs. Calcineurin is a protein phosphatase that is abundant in the brain and regulated by calcium and calmodulin. It is proposed that calcineurin plays central roles in the synaptic plasticity and neuronal apoptosis. CSA (50 mg/kg) increased the phosphorylation of ERK, CaMKII and CREB. The treatment of of CSA increased the duration of tonic phase of seizure induced by ECS and augmented the phosphorylation of ERKs after ECS. These results suggested the protective role of calcineurin against the excessive electrical and molecular activities in the brain.

A New Gene Regulated by Electroconvulsive Shock in Rat Brains / 신경정신의학

OBJECTIVES: This study was performed to identify genes regulated by electroconvulsive shock (ECS) and to observe the pattern of expression of genes according to different developmental stages and brain regions. METHODS: ECS(130V, 0.5 sec) was given to male Sprague-Dawley rats with age of postnatal day 7 and 21(P7, P21 respectively). After screening genes regulated by ECS with mRNA differential display-PCR(DD-PCR), we selected one clone among them and observed the induction of this gene after ECS by time-dependent Northern blot analysis of rat brain of P7, P21 and adult rat cortex and hippocampus. RESULTS: By DD-PCR method, we have identified four clones whose expression was regulated by ECS. Among them, one(CP 10-2) was proved to be a new gene by sequencing and BLAST search. Its expression was increased after ECS in P7, P21, and adult rat brain. The expression of CP 10-2 reached peak level at 180 minutes after ECS in P7 rat brain, but was further increased until 360 minutes after ECS in P21 and adult rat brain. CONCLUSION: In this study, a new gene was identified in rat brain which showed up-regulated expression in response to ECS. Cloning and characterization of this new gene would be helpful to elucidate the effect of ECS in rat brain.

The expression of Protein Kinase C Isozymes in the Rat Brain / 대한해부학회지

The mRNA expression of protein kinase C (PKC) isozymes (alpha, beta, gamma, delta, epsilon and zeta) in the rat nervous system was investigated with in situ hybridization histochemistry. In the central nervous system of rat, each PKC isozyme mRNAs was expressed in isozyme-specific pattern. PKC alpha mRNA was highly expressed in the olfactory bulb, piriform cortex, hippocampus, substantia nigra compacta, and inferior olive. The expression of PKC beta was highest in the olfactory tubercle, piriform cortex, caudate putamen, accumbens nucleus, neocortex, hippocampus, basolateral amygdaloid nucleus, pontine nucleus, and cerebellum. PKC gamma mRNA was distributed in the caudate putamen, hippocampus and cerebellum and PKC delta was expressed in the thalamus. PKC epsilon had widespread distribution, with relatively high levels in the anterior olfactory nucleus, olfactory tubercle, tinea tecta, piriform cortex, dorsal lateral septal nucleus, neocortex, hippocampus and cerebellum. PKC zeta had widespread and low expression. The spacially differential expression of PKC isozymes (alpha, beta, gamma, delta, epsilon and zeta) suggests that each PKC isozyme may be related with specific cellular function in the nervous system.