Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.
Adolescent ; Adult ; Brain Chemistry ; genetics ; physiology ; Cerebral Cortex ; metabolism ; pathology ; Child ; Cholecystokinin ; metabolism ; Epilepsy ; etiology ; pathology ; Female ; Gene Expression Regulation ; physiology ; Humans ; Interneurons ; metabolism ; Male ; Middle Aged ; Neuropeptide Y ; metabolism ; Parvalbumins ; metabolism ; Phosphopyruvate Hydratase ; metabolism ; Somatostatin ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism ; Young Adult

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 investigate the changes of mitochondrial distribution in axon/soma and the expression of mitochondrial fission 1 (Fis1) protein in the cortical neurons of rats with chronic fluorosis.

METHODSSixty SD rats were divided into 3 groups (20 each) according to weight hierarchy and fed with different concentrations of fluoride in drinking water (0, 10 and 50 mg/L, respectively) for 6 months. Images of mitochondria and tubulin labeled by immunofluorescence COXIV and tubulin-α were captured with fluorescence microscope. Fis1 protein expression in cortical neurons was analyzed with immunohistochemistry and Western blot. The expression of Fis1 mRNA was detected with real-time PCR.

RESULTSVarying degrees of dental fluorosis and increased fluoride contents in urine were observed in the rats receiving additional fluoride in drinking water. In the cortical neurons of rats fed with 10 mg/L and 50 mg/L fluoride, the numbers of neuronal soma stained with COXIV(34.8 ± 4.7 and 39.3 ± 3.0, respectively), and the expression of Fis1 protein (immunohistochemistry: 54.0 ± 3.6 and 51.3 ± 4.1, respectively; Western blot: 2.9 ± 0.4 and 2.6 ± 0.6, respectively) and mRNA (3773 ± 1292 and 1274 ± 162, respectively) was markedly increased as compared with controls (4.4 ± 2.3, 25.2 ± 2.5, 1.8 ± 0.2 and 277 ± 73) over the experimental period of 6 months.

CONCLUSIONSExcessive intake of fluoride results in an altered mitochondrial distribution in axon and soma in cortical neurons (i.e., the increase in soma and the decrease in axon), increased expression of Fis1 gene and enhanced mitochondrial fission. The altered mitochondrial distribution may be related to the high expression level of Fis1 and a functional disorder of mitochondria.

Animals ; Axons ; pathology ; Cerebral Cortex ; metabolism ; Drinking Water ; adverse effects ; chemistry ; Electron Transport Complex IV ; metabolism ; Female ; Fluorides ; adverse effects ; urine ; Fluorosis, Dental ; etiology ; metabolism ; pathology ; Male ; Mitochondria ; pathology ; Mitochondrial Dynamics ; drug effects ; Mitochondrial Proteins ; genetics ; metabolism ; Neurons ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tubulin ; metabolism

The rat model of multi-infarct was adopted in this study to elucidate the protective mechanism of Sailuotong capsule (Sailuotong) in recovery period of multiple cerebral infarction. The effects of Sailuotong on levels of Glu, GABA and the expression of NMDA receptor subtypes including NR1, NR2A and NR2B, were detected. The multi-infarct model rats were established by injecting embolizing microsphere via internal carotid artery, and were given Sailuotong treatment (16.5 and 33.0 mg x kg(-1)) for 60 days. The pathological changes in brain ultrastructure were observed by transmission electron microscope. The levels of Glu and GABA in brain tissue were measured with high performance liquid chromatography. The expression of NMDA receptors including NR1, NR2A and NR2B in neurons was evaluated by immunohistochemical staining. Compared with the sham rats, abnormal changes were observed in ultrastructures of neurons, neuroglia cells and synapses of model rat brains. Moreover, significant decrease of Glu and GABA, as well as the elevated expression of NR1, NR2A and NR2B were detected in brain tissues. Sailuotong (16.5 and 33.0 mg x kg(-1)) could improve ultrastructure of cerebral tissue, facilitate synthesis of Glu and GABA, and down-regulate expression of NR1, NR2A and NR2B in neurons. The results demonstrated that Sailuotong could exert neuroprotective effects to some extent in the recovery phase of multiple cerebral infarction by promoting expression of NMDA receptors and synthesis of Glu and GABA.
Animals ; Capsules ; Cerebral Cortex ; metabolism ; Cerebral Infarction ; metabolism ; pathology ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Ginkgo biloba ; chemistry ; Glutamic Acid ; metabolism ; Hippocampus ; metabolism ; Male ; Neurons ; metabolism ; pathology ; Neuroprotective Agents ; administration & dosage ; pharmacology ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; classification ; metabolism ; Synapses ; metabolism ; pathology ; gamma-Aminobutyric Acid ; metabolism

This study is to investigate the effect of the major chemical composition in rhizome of Pterocypsela elata, lactuside B, on expression of bcl-2, bax mRNA and their protein in rats' cerebral cortex after cerebral ischemia-reperfusion injury. First, middle cerebral artery ischemia-reperfusion injury model was established, and each group was treated with the corresponding medicines. Animals were separately sacrificed at 24 h and 72 h. The brain infarct volumes were detected by TTC dye, bcl-2 and bax mRNA expression was checked by RT-PCR, and the proteins of bcl-2 and bax were explored by two-step immunohistochemistry in cerebral cortex of rats. Lactuside B can reduce brain infarct volume of cerebral cortex of rats, increase the expression of bcl-2 mRNA and decrease that of bax mRNA. Moreover, the ratio of bcl-2 to bax mRNA is higher in 12.5 and 25 mg kg(-1) dose group, respectively, which is significantly different from that of model group (P < 0.05 or P < 0.01). Generally, either 12.5 or 25 mg kg(-1) dose group is better than positive control medicine nimodipine (P < 0.05 or P < 0.01). In addition, the expression of bcl-2 and bax protein is consistent with their gene expression. Infarct volume and the ratio of bcl-2 to bax mRNA expression are significantly different (P < 0.05 or P < 0.01) between 72 h and 24 h group. The results demonstrated that lactuside B could play a good role in resisting cerebral ischemia by upregulating the expression of bcl-2 mRNA and protein and downregulating that of bax mRNA and protein.
Animals ; Apoptosis ; drug effects ; Asteraceae ; chemistry ; Brain Ischemia ; metabolism ; pathology ; Cerebral Cortex ; metabolism ; pathology ; Dose-Response Relationship, Drug ; Glucosides ; administration & dosage ; isolation & purification ; pharmacology ; Male ; Neurons ; drug effects ; pathology ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; pathology ; Rhizome ; chemistry ; Vasodilator Agents ; administration & dosage ; isolation & purification ; pharmacology ; bcl-2-Associated X Protein ; genetics ; metabolism

BACKGROUNDAnnexin A7 (synexin, ANXA7) is a member of annexins, which plays an essential role in the regulation of calcium homeostasis. Considerable evidence shows that the pathogenetic mechanism of acquired epilepsy (AE) has been related to the imbalance of calcium homeostasis. The aim of this study was to investigate ANXA7 expression and cellular localization in the cortex and hippocampus in the rat lithium-pilocarpine model of AE.

METHODSTotally 81 adult healthy male Wistar rats were randomly divided into control group (n = 9) and experimental group (n = 72), the experimental group contained eight subgroups according to sacrifice time (n = 9) (6-hour, 24-hour, 48-hour, 72-hour, 7-day, 15-day, 1-month, and 2-month). In the experimental group, rats were intraperitoneally injected by lithium-pilocarpine to induce AE model. We examined the expression and localization of ANXA7 via immunohistochemistry, double-label immunofluorescence with the use of neuron specific enolase (NSE) antibody, glial fibrillary acidic protein (GFAP) antibody and propidium iodide (PI), respectively. The data of optical density value were analyzed by analysis of variance.

RESULTSANXA7 expression increased significantly in the experimental groups especially in the acute period (6 hours, 24 hours, and 48 hours after the onset of seizure) using immunohistochemistry. Double-label immunofluorescence and confocal microscopy disclosed that ANXA7 localized in the neurons but not in astrocytes and did not localize in the nucleus, which were performed with anti-NSE, anti-GFAP and PI respectively.

CONCLUSIONANXA7 may play a potential role in the pathogenetic mechanisms of the rat lithium-pilocarpine model of AE.

Animals ; Annexin A7 ; analysis ; physiology ; Calcium ; metabolism ; Cerebral Cortex ; chemistry ; Disease Models, Animal ; Fluorescent Antibody Technique ; Hippocampus ; chemistry ; Immunohistochemistry ; Lithium Chloride ; Male ; Pilocarpine ; Rats ; Rats, Wistar ; Status Epilepticus ; chemically induced ; metabolism

This study is to explore whether the Wnt/beta-catenin signaling pathway is involved in the process of tripchlorolide (T4) protecting against oligomeric Abeta(1-42)-induced neuronal apoptosis. Primary cultured cortical neurons were used for the experiments on day 6 or 7. The oligomeric Abeta(1-42) (5 micromol x L(-1) for 24 h) was applied to induce neuronal apoptosis. Prior to treatment with Abeta(1-42) for 24 h, the cultured neurons were pre-incubated with T4 (2.5, 10, and 40 nmol x L(-1)), Wnt3a (Wnt signaling agonists) and Dkk1 (inhibitors) for indicated time. Then the cell viability, neuronal apoptosis, and protein levels of Wnt, glycogen synthase kinase 3beta (GSK3beta), beta-catenin and phospho-beta-catenin were measured by MTT assay, TUNEL staining and Western blotting, respectively. The result demonstrated that oligomeric Abeta(1-42) induced apoptotic neuronal cell death in a time- and dose-dependent manner. Pretreatment with T4 significantly increased the neuronal cell survival and attenuated neuronal apoptosis. Moreover, oligomeric Abeta(1-42)-induced phosphorylation of beta-catenin and GSK3beta was markedly inhibited by T4. Additionally, T4 stabilized cytoplasmic beta-catenin. These results indicate that tripchlorolide protects against the neurotoxicity of Abeta by regulating Wnt/beta-catenin signaling pathway. This may provide insight into the clinical application of tripchlorolide to Alzheimer's disease.
Amyloid beta-Peptides ; antagonists & inhibitors ; toxicity ; Animals ; Apoptosis ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Diterpenes ; isolation & purification ; pharmacology ; Female ; Fetus ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Neurons ; cytology ; drug effects ; Neuroprotective Agents ; isolation & purification ; pharmacology ; Peptide Fragments ; antagonists & inhibitors ; toxicity ; Phenanthrenes ; isolation & purification ; pharmacology ; Phosphorylation ; Plants, Medicinal ; chemistry ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Tripterygium ; chemistry ; Wnt Proteins ; metabolism ; beta Catenin ; metabolism

OBJECTIVETo investigate the effets of flurothyl-induced neonatal recurrent seizures on glucocorticoid receptor (GR) expression in the rat brain.

METHODSForty-eight seven-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. Brains were sampled on postnatal days 13, 15 and 19. The expression of GR protein in the cerebral cortex was detected by Western blot and immunohistochemical method.

RESULTSThe expression of GR in the cerebral cortical plasma protein was significantly lower in the seizure group than in the control group on postnatal day 15. The expression of GR protein in the cerebral cortical nuclear protein decreased significantly in the seizure group compared with that in the control group on postnatal days 15 and 19 (p<0.05). Compared to the control group, the accumulated optical density (AOD) of GR immunoreactivity (IR) decreased significantly in the parietal cortex on postnatal day 13 (p<0.05), the AOD of GR IR decreased significantly in the parietal cortex and the temporal cortex on postnatal day 15 (p<0.05), and the AOD of GR IR decreased significantly in the parietal cortex, temporal cortex and the frontal cortex in the seizure group on postnatal day 19 (p<0.05).

CONCLUSIONSRecurrent seizures in neonatal rats result in abnormal GR expression in the cerebral cortex which might play an important role in short-term brain injury induced by early recurrent seizures.

Animals ; Blotting, Western ; Cerebral Cortex ; chemistry ; Female ; Hypothalamo-Hypophyseal System ; physiology ; Immunohistochemistry ; Male ; Pituitary-Adrenal System ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptors, Glucocorticoid ; analysis ; physiology ; Recurrence ; Seizures ; metabolism

OBJECTIVETo investigate the protective effects of musk extract (ME) and its possible mechanism on rat's cerebral cortical neurons with inflammatory injury induced by lipopolysaccharide (LPS).

METHODSNeurons and astrocytes from newborn rat cerebral cortex were cultured in vitro respectively, and the astrocyte conditioned medium (ACM), obtained by treating astrocytes with 10 mg/L LPS and different concentrations of ME for 24 h, was added in the culture fluid of neurons. The survival rate and apoptotic rate of neurons were measured by MTT method and AO/EB stain; and the changes of inflammatory factors in the ACM were determined by ELISA.

RESULTSThe survival rate (%) of neurons treated by ACM with ME in concentrations of 18 mg/L, 36 mg/L, 72 mg/L and 144 mg/L was 52.55 +/- 3.52, 55.77 +/- 2.36, 64.89 +/- 3.45 and 73.67 +/- 1.80, respectively, significantly higher than that in the model neurons (43.62 +/- 4. 51, P < 0.05), while the apoptotic rate (%) in them, 68.11 +/- 2.16, 44.27 +/- 3.68, 32.56 +/- 2.14 and 21.89 +/- 2.46, respectively, was significantly lower than that in model neurons (71.33 +/- 3.25, P < 0.05 or P < 0.01). Level of IL-6 was decreasing along with the raising of ME concentration in the ACM, showing a concentration-dependent state.

CONCLUSIONME shows apparent protective effect on neurons against inflammatory injury, especially in a high concentration (144 mg/L), which may be associated with the reduction of IL-6 secreted by astrocytes.

Animals ; Animals, Newborn ; Astrocytes ; cytology ; metabolism ; Cell Survival ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Fatty Acids, Monounsaturated ; chemistry ; Inflammation ; chemically induced ; prevention & control ; Interleukin-6 ; secretion ; Lipopolysaccharides ; Male ; Materia Medica ; pharmacology ; Neurons ; cytology ; Protective Agents ; pharmacology ; Rats ; Rats, Wistar

The present study was conducted to investigate the effect of hepatocyte growth factor (HGF) on cortical neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R). Primary cultured cerebral cortical neurons were prepared from Sprague-Dawley rats. The cells were used for experiments after culture for 12 d in vitro. To initiate OGD/R, the culture medium was replaced by glucose-free medium, and cells were transferred to a humidified incubation chamber flushed by a gas mixture of 95% N(2) and 5% CO(2) at 37 °C for 2 h. Following this treatment, neurons were fed with glucose-supplemented (25 mmol/L) medium, and returned to the incubator under normoxic condition for 0-24 h. The cell viability was assessed by MTT assay, and cell injury was evaluated by lactate dehydrogenase (LDH) leakage rate. The percentage of apoptotic cells was analyzed by flow cytometry and Hoechst 33258 staining. The expressions of c-Met mRNA and protein were detected by RT-PCR and Western blot analysis, respectively. Oxygen-glucose deprivation for 2 h decreased the cell viability and increased LDH leakage rate in cultured cerebral cortical neurons. The cell viability declined and LDH leakage rate increased with the reperfusion time going on (0-24 h). To explore the influence of HGF on neurons under oxygen-glucose deprivation for 2 h/reperfusion for 24 h (OGD(2)/R(24)) condition, the cultures were pretreated with HGF at different concentrations (5-120 ng/mL) 2 h prior to OGD(2)/R(24). The results showed that OGD(2)/R(24) treatment significantly decreased the cell viability, increased LDH leakage rate and the percentage of apopototic cells. Pretreatment with HGF at 5 ng/mL and 10 ng/mL did not affect the decrease in cell viability resulting from OGD(2)/R(24). In the presence of 20 ng/mL HGF, the increase in cell viability in cortical neurons exposed to OGD(2)/R(24) began to appear, and 80 ng/mL of HGF exhibited the maximal effect. HGF at 5, 10 and 20 ng/mL did not affect the increase in LDH leakage rate in cortical neurons exposed to OGD(2)/R(24). In the presence of 40 ng/mL HGF, the decrease in LDH leakage rate in cortical neurons subjected to OGD(2)/R(24) began to appear, and 80 ng/mL of HGF displayed the maximal effect. In addition, HGF at 80 ng/mL significantly attenuated cell apoptosis resulting from OGD(2)/R(24). As detected by semi-quantitative RT-PCR and Western blot analysis, c-Met mRNA and protein were expressed in cerebral cortical neurons cultured for 12 d in vitro. c-Met mRNA and protein expressions in cortical neurons exposed to OGD(2)/R(24) were significantly upregulated and were not affected by pretreatment of HGF at 80 ng/mL. Treatment with c-Met inhibitor SU11274 (5 μmol/L) completely eliminated HGF-mediated protection of cortical neurons subjected to OGD(2)/R(24). The results suggest that HGF directly protects cortical neurons against OGD/R-induced cell injury in a dose-dependent manner, and HGF has a potent anti-apoptotic action on neurons exposed to OGD/R.
Animals ; Apoptosis ; Cell Hypoxia ; Cell Survival ; Cells, Cultured ; Cerebral Cortex ; cytology ; Culture Media ; chemistry ; Glucose ; chemistry ; Hepatocyte Growth Factor ; pharmacology ; L-Lactate Dehydrogenase ; metabolism ; Neurons ; cytology ; metabolism ; Oxygen ; chemistry ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury