OBJECTIVETo study the role of catecholamine(CA) in the mechanism of bio-effect of electromagnetic irradiation.

METHODSThe contents of norepinephrine (NE), epinephrine (E) and dopamine (DA) in serum and hippocampus of rats at 0, 8, 24, 48 hours after electromagnetic irradiation were measured by using high performance liquid chromatography with electrochemical detector(HPLC-ECD), and the influence of two kinds of shelter on CA was studied.

RESULTSThe levels of CA in serum and hippocampus increased obviously in an instant, decreased at 8 h and increased significantly again at 24 h after irradiation without shielding irradiation. But at 48 h, the levels of NA, DA in hippocampus were still higher and the serum's NA, DA were not different from the control. After irradiation with whole body shielding, the levels of CA had no changes. The contents of CA increased significantly only at 24 h after irradiation by 65 W/cm2 electromagnetic wave with trunk shielding. After irradiation by 129 W/cm2 with trunk shielding, the change of CA were similar to that of no shielding.

CONCLUSIONCA may take part in the injury to central nervous system and cardiovascular system after electromagnetic irradiation. And the injury to central nervous system may sustain longer than that of cardiovascular system. The protective effect of whole body shielding is the best, while trunk shielding may have some protective effect following lower and middle power electromagnetic wave. The most important protective measure is to shield the head.

Animals ; Catecholamines ; analysis ; blood ; Chromatography, High Pressure Liquid ; Electrochemistry ; Electromagnetic Phenomena ; Hippocampus ; chemistry ; radiation effects ; Rats

The chemical constituents and action targets of Acori Tatarinowii Rhizoma and Curcumae Radix were screened by network pharmacological method,and the mechanism of the combination of Acori Tatarinowii Rhizoma and Curcumae Radix in the treatment of epilepsy was analyzed. All chemical constituents of Acori Tatarinowii Rhizoma and Curcumae Radix were retrieved by TCMSP,and their action targets were screened. Component target PPI network was constructed. Epilepsy-related genes were retrieved from PharmGkb database,and PPI networks of disease targets were drawn by Cytoscape software. Cytoscape software was used to merge the network,screen the core network,and further analyze the gene GO function and KEGG pathway enrichment,which was verified by experimental research. One hundred and five chemical constituents of Acori Tatarinowii Rhizoma and 222 chemical constituents of Curcumae Radix were retrieved. Nineteen compounds were selected as candidate compounds according to OB and DL values. Among them,4 chemical constituents of Acori Tatarinowii Rhizoma and 15 chemical constituents of Curcumae Radix were found. A total of 88 target proteins were retrieved by retrieving TCMSP data,and PPI network was constructed. Through PharmGkb database,29 epilepsy-related genes were retrieved and disease target network was established. Cytoscape software and plug-ins were used for network merging and core network screening,and 69 genes were screened out. Through GO function analysis and KEGG pathway analysis,the mechanism of anti-epilepsy is related to prolactin signaling pathway,HTLV-Ⅰ infection signaling pathway,MAPK signaling pathway and herpes simplex infection signaling pathway. Further experimental verification showed that the serum prolactin level in epileptic rats was significantly increased. The neurons in hippocampal CA1 area degenerated,necrotized and lost 24 hours after epileptic seizure,and some neuron interstitial edema occurred. The possible mechanism of compatibility of Acori Tatarinowii Rhizoma and Curcumae Radix is related to serum prolactin level,MAPK signaling pathway,HTLV-Ⅰ infection and herpes simplex infection. The analysis may be related to viral encephalitis caused by HTLV-Ⅰ virus and herpes simplex infection,which damages nerve cells and causes seizures.
Acorus ; chemistry ; Animals ; CA1 Region, Hippocampal ; drug effects ; pathology ; Curcuma ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Epilepsy ; drug therapy ; Hippocampus ; Plant Roots ; chemistry ; Rats ; Rhizome ; chemistry

OBJECTIVETo investigate the developmental profiles on surface expression and co-localization of NMDA receptor clusters and AMPA receptor clusters on dendrite in cultured hippocampal neurons of rats.

METHODSGreen fluorescent protein tagged GluR2 subunit (GFP-GluR2) and FLAG tagged NR2B subunit (FLAG-NR2B) were transfected into cultured hippocampal neurons at 5 days in vitro (DIV5). FLAG-NR2B containing NMDA receptor clusters and GFP-GluR2 containing AMPA receptor clusters expressed on membrane surface were then labeled in living neurons using anti FLAG mAb/Cy3-conjugated anti-mouse antibody and anti-GFP pAb/Alex488-conjugated anti-rabbit antibody.

RESULTThe numbers of receptor cluster per 100 microm dendrite in the neurons at DIV7 and DIV19 were 39.7+/-5.0 and 64.7+/-6.1 (P<0.01) for NR2B-NMDAR, 59.1+/-3.3 and 99.7+/-6.4 (P<0.01) for GluR2-AMPAR, and 29.9+/-4.5 and 37.5+/-2.5(P<0.05) for the co-localized, respectively. At DIV7 and DIV19, 75.4% and 57.9% NR2B-NMDAR clusters were co-localized with GluR2-AMPAR; and 50.6% and 37.6% GluR2-AMPAR clusters were co-localized with NR2B-NMDAR, respectively.

CONCLUSIONThe density of NR2B-NMDAR containing and GluR2-AMPAR containing receptor clusters increases during development of hippocampal neurons in culture. Although the co-localized clusters are increased as well in an unit length of dendrite, the extent to which the two receptor clusters are co-localized decreases. These data imply a possible change in the partnership of AMPA receptor subtype and NMDA receptor subtype at newly formed synapses during development.

Animals ; Cells, Cultured ; Dendrites ; chemistry ; Hippocampus ; chemistry ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA ; analysis ; Receptors, N-Methyl-D-Aspartate ; analysis

AIMTo simultaneously determine three unconjugated neurosteroids, dehydroepiandrosterone (DHEA) , pregnenolone (PREG), allopregnenolone (AP), from several brain regions of the rat.

METHODSNeurosteroids were isolated separately in a two steps procedure by using ethyl acetate-n-hexane (90:10) as the first step to extract the unconjugated steroids, then the steroid fractions were further purified by SPE. All steroids were derivatized with 2-nitro-4-trifluoromethylphenylhydrazine (2-NFPH) and analyzed by HPLC-MS ( APCI) using selected-ion monitoring. Methyltestosterone was chosen as the internal standard. Results The linear calibration curve of DHEA was obtained in the concentration range of 0.030-2.00 microg x L(-1). The linear calibration curves of PREG and AP were obtained in the concentration range of 0.025-2.00 microg x L(-1). The concentrations of DHEA, PREG and AP in male rat brain regions were (0.70 +/- 0.23), (4.8 +/- 1.9), (1.1 +/- 0.6) ng x g(-1) for frontal cortex, (0.57 +/- 0.28), (6 +/- 3), (0.5 +/- 0.3) ng x g(-1) for hippocampus, (1.5 +/- 1.0), (9 +/- 5), (1.4 +/- 0.9) ng x g(-1) for amygdale, (0.52 +/- 0.14), (7.7 +/- 2.8), (0.5 +/- 0.6) ng x g(-1) for striatum, (2.9 +/- 1.6), (18 +/- 9), (1.6 +/- 1.3) ng x g(-1) for nucleus accumbens, (4.0 +/- 2.0), (27 +/- 12), (0.8 +/- 0.5) ng x g(-1) for pituitary gland, (1.7 +/- 1.2), ( 16 +/- 10), and (0. 8 +/- 0.7) ng x g(-1) for hypothalamus, respectively.

CONCLUSIONGood linearity and accuracy were observed for each steroid. The procedure was suitable for measuring concentrations of the unconjugated steroids in rat brain simultaneously.

Amygdala ; chemistry ; Animals ; Brain Chemistry ; Chromatography, High Pressure Liquid ; Corpus Striatum ; chemistry ; Dehydroepiandrosterone ; analysis ; Hippocampus ; chemistry ; Hypothalamus ; chemistry ; Male ; Mass Spectrometry ; methods ; Nucleus Accumbens ; chemistry ; Prefrontal Cortex ; chemistry ; Pregnenolone ; analogs & derivatives ; analysis ; Rats ; Rats, Sprague-Dawley ; Sensitivity and Specificity

OBJECTIVETo investigate the epileptic seizure-like effect of Sophora alkaloid sophoridine on electroencepholography (EEG) and its possible characteristic and the mechanism of the seizure-like effect.

METHODChronic electron implantation was employed for the intracranial electroencepholography (IEEG) recording in rat, and the traditional anti-seizure drugs were for the mechanism study in mice.

RESULTCompared with the medial perforant path (PP) area and the temporal cortex (TC), the granule cells in hippocampus dentate gyrus (DG) area is more sensitive in the kindling effect by sc sophoridine. Under-threshold hypnotic dosage of diazepam and the hypnotic dosage of pentobarbital sodium can block the sophoridine kinded seizure in mice, but the phenytoin sodium can not block the seizure, also the dosage of it can block the maximal electroconvulsive shock (MES) seizure.

CONCLUSIONSophoridine-induced synchronous oscillations in the hippocampus could elicit the generation and development of seizure. And the hippocampus might play the crucial role and be the original part of the seizure. Sophoridine kinded seizure might belong to clonic seizures, and the diazepam is the ideal agent for the treatment.

Alkaloids ; chemistry ; pharmacology ; Animals ; Epilepsy ; chemically induced ; metabolism ; Hippocampus ; drug effects ; metabolism ; Male ; Mice ; Quinolizines ; chemistry ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sophora ; chemistry

OBJECTIVETo study the level of brain-derived neurotrophic factor (BDNF) in the microenvironment of the neuron-astrocyte co-culture system by Mg2+-free-induced seizure-like discharge and analyze the source of BDNF.

METHODSHippocampal neurons (N) of fetal rats and astrocytes (AST) of neonatal rats were purified and divided into four groups, included control N (Con N) group, Mg2+-free treated N (Mg2+-free N) group, control N+AST co-culture (Con N+AST) group and Mg2+-free treated N+AST co-culture (Mg2+-free N+AST) group. The Mg2+-free treated groups were exposed to Mg2+-free media for 3 hrs to induce a repeated spontaneous seizure-like discharge. The level of BDNF in each group at different time points was measured using ELISA.

RESULTSThe cellular morphous of AST changed in the Mg2+-free N+AST group at 48 hrs. Neuronal epileptiform activity was observed in the Mg2+-free media at 3 hrs, and continued to exist until the microenvironment returned to normal for 72 hrs. The BDNF level increased at 24 hrs and 48 hrs in the Con N+AST group compared with the control N group (P<0.05). Compared with Con N+AST group, BDNF level increased at 12, 24 and 48 hrs in the Mg2+-free N+AST group, especially at 12 and 24 hrs (P<0.01). There were no significant differences in the level of BDNF between the Con and Mg2+-free N groups. Compared with Mg2+-free N group, BDNF level increased at 24 hrs in the Mg2+-free N+AST group (P<0.05).

CONCLUSIONSThe results of the experiment suggest that BDNF in the Con N+AST group might be excreted from both N and AST, but chiefly from N. Activated AST may be the main source for increasing BDNF in the Mg2+-free N+AST group.

Animals ; Astrocytes ; chemistry ; Brain-Derived Neurotrophic Factor ; analysis ; Cellular Microenvironment ; Coculture Techniques ; Female ; Hippocampus ; chemistry ; Magnesium Deficiency ; metabolism ; Male ; Neurons ; chemistry ; Rats ; Rats, Wistar ; Seizures ; metabolism

OBJECTIVETo investigate the effects of preweaning enrichment on the expression of activity-regulated cytoskeletal protein (Arc), an immediate early gene, and on the long-term memory in rats.

METHODSForty neonatal Sprague-Dawley rats were randomly assigned to control group (standard environment, n=20) and experimental group (enriched environment, n=20). The experimental group received enriched environment exposure from postnatal day 10 until weaning (2 weeks, 20 minutes per day). The open field and novel object recognition tests were performed at postnatal day 28. Arc expression was detected by Western blotting and immunohistochemistry.

RESULTSThere was no significant difference in the open field test between the two groups. However, in the novel object recognition test, the experimental group rats performed significantly better than the control rats after 1 and 24-hr retention. The preference index in the experimental group after 1-hr (59.61%+/-9.61% vs 50.46%+/-9.34%; P<0.05) and 24-hr retention (62.72%+/-14.12% vs 52.39%+/-9.16%; P<0.05 ) was significantly higher than that in the control group. Arc expression in both areas CA1 and DG of hippocampus in the experimental group increased significantly compared with that in the control group (P<0.01).

CONCLUSIONSPreweaning enrichment can up-regulate the expression of immediate early gene, Arc, in the hippocampus of the rats, and promote their long-term memory.

Animals ; Cytoskeletal Proteins ; analysis ; Female ; Hippocampus ; chemistry ; physiology ; Immunohistochemistry ; Male ; Memory ; Nerve Tissue Proteins ; analysis ; Rats ; Rats, Sprague-Dawley

Voltage-gated sodium channels (VGSCs), which are widely distributed in the excitable cells, are the primary mediators of electrical signal amplification and propagation. They play important roles in the excitative conduction of the neurons and cardiac muscle cells. The abnormalities of the structures and functions of VGSCs can change the excitability of the cells, resulting in a variety of diseases such as neuropathic pain, epilepsy and arrhythmia. At present, some voltage-gated sodium channel blockers are used for treating those diseases. In the recent years, several neurotoxins have been purified from the venom of the animals, which could inhibit the current of the voltage-gated sodium channels. Usually, these neurotoxins are compounds or small peptides that have been further designed and modified for targeted drugs of sodium channelopathies in the clinical treatment. In addition, a novel cysteine-rich secretory protein (CRBGP) has been isolated and purified from the buccal gland of the lampreys (Lampetra japonica), and it could inhibit the Na+ current of the hippocampus and dorsal root neurons for the first time. In the present study, the progress of the sodium channelopathies and the biological functions of voltage-gated sodium channel blockers are analyzed and summarized.
Animals ; Channelopathies ; physiopathology ; Hippocampus ; drug effects ; Neurons ; drug effects ; Neurotoxins ; pharmacology ; Venoms ; chemistry ; Voltage-Gated Sodium Channel Blockers ; pharmacology

OBJECTIVETo investigate the effect of lead exposure on copper and copper metalloenzyme and the intervention effect of quercetin.

METHODSTwenty-four specific pathogen-free male Sprague-Dawley rats of good health were randomly divided into control group (n = 8), lead acetate group (n = 8), and lead acetate + quercetin group (n = 8). The rats in lead acetate group were poisoned by drinking water with 1 g/L lead acetate for 8 weeks, while the rats in control group were fed by drinking water with sodium acetate of the same volume for 8 weeks; the rats in lead acetate+quercetin group were intraperitoneally injected with quercetin (30 mg × kg-1 × d-1) for 8 weeks while drinking water with lead acetate. The Morris water maze was used to test the learning and memory abilities of rats. The lead and copper levels in the serum, hippocampus, cortex, and bone were measured by graphite furnace atomic absorption spectrometry. The level of advanced glycation end products, activity of Cu/Zn superoxide dismutase (SOD), and content and activity of ceruloplasmin (CP) in the hippocampus and serum were measured using a test kit. HE staining was performed to observe the pathological changes in the hippocampus.

RESULTSThe Morris water maze test showed that the latency in lead acetate group (52.50±12.04 s) was significantly longer than that in control group (28.08±7.31 s) (P<0.05), and the number of platform crossings was significantly lower in the lead acetate group than in the control group. Compared with those in the control group, the lead levels in the cortex and hippocampus in lead acetate group increased 2.72-fold and 3.79-fold, and the copper in the cortex and hippocampus, and serum free copper levels in lead acetate group increased 1.15-fold, 1.48-fold, and 6.44-fold. Compared with the control group, the lead acetate group had a lower content of CP in the hippocampus (1.23±0.40 U/mg provs0.78±0.08 U/mg pro) and 31.81%and 19.49%decreases in CP content and Cu/Zn SOD activity. Free copper level in serum was positively correlated with the latency and lead levels in the serum, cortex, and hippocampus. The escape latency of rats in lead acetate + quercetin group was decreased by 42.15% (P<0.05). The lead levels in the cortex and hippocampus in lead acetate + quercetin group (0.246 ± 0.58 µg/g and 0.202±0.049 µg/g) were significantly lower than those in lead acetate group (0.391±0.49 µg/g and 0.546±0.120 µg/g), but the free copper and copper levels in the hippocampus and cortex were not significantly reduced. The lead acetate + quercetin group had higher Cu/Zn SOD activity and CP content in the hippocampus than the lead acetate group (P < 0.05). The light microscope observation showed that the number of cells in the hippocampus was reduced with disordered arrangement in the lead acetate group; with quercetin intervention, the hippocampus damage was reduced.

CONCLUSIONLead exposure results in disorder of copper homeostasis, while quercetin may alleviate the damage induced by lead to some extent.

Animals ; Cerebral Cortex ; chemistry ; Copper ; blood ; Hippocampus ; chemistry ; Homeostasis ; Learning ; drug effects ; Male ; Memory ; drug effects ; Organometallic Compounds ; toxicity ; Quercetin ; pharmacology ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

OBJECTIVETo explore the difference between adolescent and adult C57BL/6J mice in response to rapid eye movement sleep (REMS) deprivation in terms of anxiety behavior and hippocampal NO level.

METHODSBoth adolescent and adult C57BL/6J mice were divided into normal control (NC) group, wide platform (WP) group, and 24-hour REMS deprivation group, each group consisting of 15 mice. REMS deprivation models were established using a small platform in water tank, and the elevated plus maze test was used to examine anxiety behavior of the mice. After behavioral tests, the mice were sacrificed to examine hippocampal NO levels using enzyme-linked immunosorbent assay, and hippocampal nNOS protein expression was detected with Western blotting.

RESULTSThe adolescent C57BL/6J mice showed no obvious differences in anxiety behaviors between the 3 groups, but NO level and nNOS expression in the hippocampus was significantly higher in REMSD group than in NC and WP groups (P<0.01). The adult mice in REMSD group, compared with those in the other two groups, exhibited significantly increased total number of arm entry (P<0.01), lowered number of open arm entry and reduced open arm time (P<0.01), increased number of close arm entry and prolonged close arm time (P<0.01 or 0.05); no obvious differences in NO level or nNOS expression in the hippocampus were found in the 3 groups of adult mice.

CONCLUSIONREMS deprivation produces different effects on anxiety-related behaviors between adolescent and adult mice possibly in relation to their different responses in terms of NO levels and nNOS expression in the hippocampus.

Animals ; Anxiety ; Hippocampus ; chemistry ; Mice ; Mice, Inbred C57BL ; Nitric Oxide ; chemistry ; Nitric Oxide Synthase Type I ; metabolism ; Sleep Deprivation ; Sleep, REM