Downregulation of microRNA-124 predicts poor prognosis in glioma patients.

The aim of the present study was to investigate the clinical significance of microRNA-124 (miR-124) expression in glioma. The expression levels of miR-124 were measured using quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The correlation between the miR-124 levels and the clinicopathological factors of the glioma patients was analyzed. The survival curves were calculated by the Kaplan-Meier method. The influence of each variable on survival was examined by the Cox multivariate regression analysis. Compared with nonneoplastic brain tissues, the expression level of miR-124 was significantly decreased in glioma tissues (1.27 ± 0.55 versus 6.91 ± 1.06, P < 0.0001). The expression level of miR-124 was positively correlated with grade (P = 0.003) and Karnofsky performance status (KPS) score (P = 0.008). A significant difference was found that glioma patients with low miR-124 expression level had distinctly shorter OS (P = 0.001) and PFS (P = 0.002) than patients with high miR-124 expression level. Furthermore, we found that low miR-124 expression (OS P = 0.009; PFS P = 0.002) and advanced histologic grade (OS P = 0.005; PFS P = 0.001) were independent prognostic parameters indicating poor prognosis for glioma patients. Our results showed that the decreased expression of miR-124 may be associated with malignant tumor progression and poor prognosis in patients with gliomas, suggesting that miR-124 may be a novel and valuable signature for predicting the clinical outcome of patients with gliomas.

Analysis and Identification Genetic Effect of SARS-CoV-2 Infections to Alzheimer's Disease Patients by Integrated Bioinformatics.

BACKGROUND: COVID-19 pandemic is a global crisis which results in millions of deaths and causes long-term neurological sequelae, such as Alzheimer's disease (AD). OBJECTIVE: We aimed to explore the interaction between COVID-19 and AD by integrating bioinformatics to find the biomarkers which lead to AD occurrence and development with COVID-19 and provide early intervention. METHODS: The differential expressed genes (DEGs) were found by GSE147507 and GSE132903, respectively. The common genes between COVID-19 and AD were identified. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interactions (PPI) network analysis were carried out. Hub genes were found by cytoscape. A multivariate logistic regression model was constructed. NetworkAnalyst was used for the analysis of TF-gene interactions, TF-miRNA coregulatory network, and Protein-chemical Interactions. RESULTS: Forty common DEGs for AD and COVID-19 were found. GO and KEGG analysis indicated that the DEGs were enriched in the calcium signal pathway and other pathways. A PPI network was constructed, and 5 hub genes were identified (ITPR1, ITPR3, ITPKB, RAPGEF3, MFGE8). Four hub genes (ITPR1, ITPR3, ITPKB, RAPGEF3) which were considered as important factors in the development of AD that were affected by COVID-19 were shown by nomogram. Utilizing NetworkAnalyst, the interaction network of 4 hub genes and TF, miRNA, common AD risk genes, and known compounds is displayed, respectively. CONCLUSION: COVID-19 patients are at high risk of developing AD. Vaccination is required. Four hub genes can be considered as biomarkers for prediction and treatment of AD development caused by COVID-19. Compounds with neuroprotective effects can be used as adjuvant therapy for COVID-19 patients.

Remote programming for subthalamic deep brain stimulation in Parkinson's disease.

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective for the treatment of Parkinson's disease (PD). Moreover, remote programming is widely used in Mainland China. This necessitates evaluating the ability of remote programming to achieve the ideal postoperative effect. Therefore, we aimed to retrospectively evaluate the effects of different programming modes on the effectiveness of STN-DBS 12 months postoperatively in patients with PD. Methods: Clinical data were collected retrospectively, before and 12 months after surgery, in 83 patients with PD. Based on the programming modes voluntarily selected by the patients during 12 months postoperatively, they were divided into three groups, namely remote programming alone, hospital programming alone, and hospital + remote programming. We compared the programming data and the effects of different programming methods on STN-DBS-related improvements 12 months postoperatively among these groups. Furthermore, we analyzed STN-DBS-related improvements at 12 months postoperatively in 76 patients. Results: The effectiveness of STN-DBS was not influenced by the three programming modes. The postoperative Movement Disorder Society Unified Parkinson's Disease Rating Scale scores did not reveal statistically significant differences between the remote alone and hospital alone programming groups, except for motor examination. The postoperative decline in the levodopa equivalent daily dose was most apparent in the hospital programming alone group. The programming frequency of the hospital + remote programming group was considerably higher than that of the remaining groups. Seventy-six patients with PD displayed good STN-DBS surgical efficacy. Conclusion: Programming modes do not influence the short-term efficacy of STN-DBS, and remote programming can yield a satisfactory surgical effect.

Decreased purinergic inhibition of synaptic activity in a mouse model of Niemann-Pick disease type C.

Niemann-Pick disease type C (NPC) is a progressive neurodegenerative disorder characterized by accumulation of free cholesterol in lysosomes, mainly due to a mutation in the NPC1 gene. The pathophysiological basis of the neural disorders in NPC, however, is not well understood. We found that the hippocampal field excitatory postsynaptic potential (fEPSP) was enhanced in NPC1 mutant mice. A1-receptor antagonist or adenosine degrading enzyme enhanced the fEPSP in both types of mice, but had a much weaker effect in the mutant mice, suggesting less tonic inhibition of synaptic transmission by endogenous adenosine in the mutant. Further evidence showed impaired hippocampal long term potentiation (LTP) in mutant mice. Supplement of A1 agonist N6-Cyclopentyladenosine (CPA) partially rescued the impaired LTP in mutant mice. Moreover, adenosine release from hippocampal slices was significantly decreased in the mutant. The enhanced excitatory synaptic transmission and the decreased synaptic plasticity due to the decreased adenosine release in NPC brain may partially contribute to the neural disorders of NPC disease, such as seizures, neurodegeneration, and dementia.

Identification of Blood-Based Glycolysis Gene Associated with Alzheimer's Disease by Integrated Bioinformatics Analysis.

BACKGROUND: Alzheimer's disease (AD) is one of many common neurodegenerative diseases without ideal treatment, but early detection and intervention can prevent the disease progression. OBJECTIVE: This study aimed to identify AD-related glycolysis gene for AD diagnosis and further investigation by integrated bioinformatics analysis. METHODS: 122 subjects were recruited from the affiliated hospitals of Ningbo University between 1 October 2015 and 31 December 2016. Their clinical information and methylation levels of 8 glycolysis genes were assessed. Machine learning algorithms were used to establish an AD prediction model. Receiver operating characteristic curve (AUC) and decision curve analysis (DCA) were used to assess the model. An AD risk factor model was developed by SHapley Additive exPlanations (SHAP) to extract features that had important impacts on AD. Finally, gene expression of AD-related glycolysis genes were validated by AlzData. RESULTS: An AD prediction model was developed using random forest algorithm with the best average ROC_AUC (0.969544). The threshold probability of the model was positive in the range of 0∼0.9875 by DCA. Eight glycolysis genes (GAPDHS, PKLR, PFKFB3, LDHC, DLD, ALDOC, LDHB, HK3) were identified by SHAP. Five of these genes (PFKFB3, DLD, ALDOC, LDHB, LDHC) have significant differences in gene expression between AD and control groups by Alzdata, while three of the genes (HK3, ALDOC, PKLR) are related to the pathogenesis of AD. GAPDHS is involved in the regulatory network of AD risk genes. CONCLUSION: We identified 8 AD-related glycolysis genes (GAPDHS, PFKFB3, LDHC, HK3, ALDOC, LDHB, PKLR, DLD) as promising candidate biomarkers for early diagnosis of AD by integrated bioinformatics analysis. Machine learning has the advantage in identifying genes.

Partial epilepsy with antecedent febrile seizures and seizure aggravation by antiepileptic drugs: associated with loss of function of Na(v) 1.1.

PURPOSE: Generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy in infancy (SMEI) are associated with sodium channel α-subunit type-1 gene (SCN1A) mutations. Febrile seizures and partial seizures occur in both GEFS+ and SMEI; sporadic onset and seizure aggravation by antiepileptic drugs (AEDs) are features of SMEI. We thus searched gene mutations in isolated cases of partial epilepsy with antecedent FS (PEFS+) that showed seizure aggravations by AEDs. METHODS: Genomic DNA from four patients was screened for mutations in SCN1A, SCN2A, SCN1B, and GABRG2 using denaturing high-performance liquid chromatography (dHPLC) and sequencing. Whole-cell patch clamp analysis was used to characterize biophysical properties of two newly defined mutants of Na(v) 1.1 in tsA201 cells. RESULTS: Two heterozygous de novo mutations of SCN1A (R946H and F1765L) were detected, which were proven to cause loss of function of Na(v) 1.1. When the functional defects of mutants reported previously are compared, it is found that all mutants from PEFS+ have features of loss of function, whereas GEFS+ shows mild dysfunction excluding loss of function, coincident with mild clinical manifestations. PEFS+ is similar to SMEI clinically with possible AED-induced seizure aggravation and biophysiologically with features of loss of function, and different from SMEI by missense mutation without changes in hydrophobicity or polarity of the residues. CONCLUSIONS: Isolated milder PEFS+ may associate with SCN1A mutations and loss of function of Na(v) 1.1, which may be the basis of seizure aggravation by sodium channel-blocking AEDs. This study characterized phenotypes biologically, which may be helpful in understanding the pathophysiologic basis, and further in management of the disease.

[Selective radiofrequency thermocoagulation for trigeminal neuralgia].

OBJECTIVE: To study the technique and experience of selective radiofrequency thermocoagulation (SRFTC) for trigeminal neuralgia (TN) and the application of neuronavigation in SRFTC for TN. METHODS: SRFTC was performed in 3269 TN patients and neuronavigation-assisted SRFTC in 36 of them. Follow-up was carried out for over 2 years in 1722 cases. RESULTS: An excellent efficacy was achieved in 2590 cases, a fair outcome in 548 cases and no response in 131 cases. The recurrence rates at one and two years were 10.5% and 25.0% respectively. The efficacy was excellent in all cases treated by neuronavigation-assisted SRFTC. The effective rate was 96%. Neither serious complication nor death occurred in this series. CONCLUSION: SRFTC for TN is both safe and effective. And the neuronavigation technique can not only increase the surgical efficacy of SRFTCP for TN but also decrease the surgical risks.

The effects of drying following heat shock exposure of the desert moss Syntrichia caninervis.

Desert mosses are components of biological soil crusts (BSCs) and their ecological functions make assessment and protection of these mosses a high-ranking management priority in desert regions. Drying is thought to be useful for desert mosses surviving heat shock. In this study, we investigated the role of drying by monitoring the responses of physiological characters and asexual reproduction in the typical desert moss Syntrichia caninervis. Heat significantly decreased chlorophyll content and weakened rapid recovery of photochemical activity, and increased carotenoid content and membrane permeability. Lethal temperatures significantly destroyed shoot regeneration potential. In comparison with heat alone, drying significantly increased protonema emergence time and depressed protonema emergence area. Drying combined with heat accelerated water loss, followed by a decrease of photosynthetic activity. Drying had different influences on membrane permeability at different temperatures. When moss leaves were subjected to a combined stress of drying and heat shock, photosynthesis was maintained mainly due to the effects of drying on physiological activity although the cellular morphological integrity was affected. Drying caused opposing effects on moss physiological and reproductive characteristics. On the one hand, drying caused a positive synergistic effect with heat shock when the temperature was below 40 degrees C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 degrees C. These findings may help in understanding the survival mechanism of dessert mosses under heat shock stress which will be helpful for the artificial reconstruction of BSCs.

Quantitative analysis of synaptic vesicle release and readily releasable pool size in hippocampal neurons.

In central nervous system only a limited number of vesicles exist in the presynaptic terminals. The size and fusion modes of the vesicles were particularly important because of their potential impact on neuronal communications. Efficient methods were needed to analyze the recycling kinetics of synaptic vesicle and the size of readily releasable pool (RRP). In this study, fluorescent dyes with different affinity for membranes (FM1-43 with high affinity and FM2-10 with low affinity) were used to stain the functional synaptic vesicles of cultured hippocampal neurons and the kinetics of vesicle recycling was measured. The results showed that the destaining proportion was larger for FM2-10 than that for FM1-43 during the first trial, while it was greater for FM1-43 than FM2-10 during the second and third trials (first round, 93.0%+/-5.9% versus 57.9%+/-3.5% for FM2-10 and FM1-43, respectively, P<0.0001; second round, 1.4%+/-3.8% versus 24.0%+/-2.3%, P<0.0001; third round, 2.3%+/-1.6% versus 8.6%+/-1.5%, P=0.005). The results indicated that rapid endocytosis existed not only in the first round but also occurred when the vesicles were reused. Moreover, Both high-frequency stimuli and hypertonic sucrose stimuli were used to estimate the RRP sizes in the mix cultured hippocampal inhibitory neurons at 13-14 days in vitro (DIV). We found that the RRP size estimated by hypertonic sucrose stimuli [(200+/-23.0) pC] was much larger than that estimated by high-frequency stimuli [(51.1+/-10.5) pC]. One possible reason for the discrepancies in RRP estimates is that in mix cultured conditions, one neuron may receive inputs from several neurons and hypertonic sucrose stimuli will cause RRP of all those neurons release, while using dual patch recording, only the connection between two neurons was analyzed. Thus, to exclude out the impacts of inputs numbers on RRP sizes, it is more reasonable to use high-frequency stimuli to estimate the RRP size in mix cultured neurons.

Prognostic and Clinic Pathological Value of Cx43 Expression in Glioma: A Meta-Analysis.

Gap junctional intercellular communication (GJIC) composed of connexin proteins is considered vital to cancer onset and progression since 50 years ago based on Lowenstein and Kano's works, however altered expression of connexins is still a lesser known "hallmark" of cancer. Although many studies support the hypothesis that connexins are tumor suppressors, recent evidence indicates that, in some tumor types including glioma, they may play contradictory role in some specific stages of tumor progression. We thus conduct a meta-analysis to evaluate the prognostic role of Cx43 in glioma for the unanswered questions that whether Cx43 is a beneficial or insalubrity factor for glioma. Eight studies with 1,706 patients were included for meta-analysis. The results showed that Cx43 expression was a clearly negative factor with tumor grades (I 2 = 34%, P < 0.001) and beneficial for OS (n = 3, HR 2.62, 95%CI 1.47-4.68; P = 0.001). Subgroup analysis also found that Cx43 had different expression in Asian young patients vs. other groups. In conclusion, this article summarize the prognostic value of Cx43 and offer a clinical evidence for the notion that Cx43 is generally a tumor suppressor and beneficial for the patients' survival time.

Effect of LRRK2 G2385R Variant on Subthalamic Deep Brain Stimulation Efficacy in Parkinson's Disease in a Han Chinese Population.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson's disease (PD). The G2385R variant of LRRK2 is a risk factor for PD in Han Chinese individuals. We retrospectively compared the clinical outcomes of STN-DBS surgery between PD Han Chinese G2385R variant carriers and non-carriers. Fifty-seven PD patients with bilateral STN-DBS were enrolled, including 8 G2385R+ variant carriers (G2385R+ group) and 49 non-carriers (G2385R- group). Clinical data included Unified Parkinson's Disease Rating Scale (UPDRS) parts I to IV, levodopa equivalent daily dose (LEDD), Mini-Mental State Examination Scale (MMSE) score, and Hamilton Depression Rating Scale (HAMD) score measured prior to DBS and 12 months post-DBS. DBS settings were also recorded. All PD patients benefited from STN-DBS surgery. There were no statistical differences between the two groups in terms of motor function, daily living activities, and LEDD reductions at 12 months post-DBS. The rigidity of the post-surgical G2385R+ group was significantly improved compared with that of the G2385R- group (P = 0.045). Post-surgical voltage in the G2385R+ group was significantly higher than that in the G2385R- group (P = 0.033). STN-DBS outcomes were not influenced by the LRRK2 G2385R variant in Han Chinese patients.

[Diagnosis and treatment of chronic expanding intracerebral hematoma].

OBJECTIVE: To explore the diagnosis, therapeutic strategy, and pathogenetic mechanism of chronic expanding intracerebral hematoma (CEICH). METHODS: The clinical presentation, radiological characteristics, d pathology, and treatment of 22 cases of CEICH, 15 males and 7 females, aged 29. 3, all treated with craniotomy and removal of the wall of the capsule and hematoma, were analyzed retrospectively. RESULTS: The clinical presentation and radiological characteristics of CEICH were atypical. After surgery, 18 patients recovered quite well, 3 patients suffered from hemiplegia, and 1 patient died from rebleeding. The diagnosis of CEICH of all the cases was confirmed by intraoperative finding and pathological results. CONCLUSION: CEICH can be found in any part of the brain that has 2 major characteristics: its clinical symptoms always develop slowly, and the typical radiological characteristic is intracerebral hematoma-form image. Surgery to evacuate the hematoma and remove the capsule is necessary and can be with good outcome.

[Live imaging and quantitative analysis of dendritic development of cultured rat hippocampal neurons].

OBJECTIVE: To measure mobility of dendritic filopodia, complexity of dendritic arborization using method of live imaging in cultured rat hippocampal neurons and to analyze their morphological characters quantitatively. METHODS: Vectors expressing Green Fluorescent Protein- Fibrous Actin (GFP-F-Actin) and F-GFP were co-transfected into cultured rat hippocampal neurons at 5 d in vitro (DIV 5). Neurons expressing GFP were photographed and analyzed with Metamorph software. RESULT: Dendritic filopodia was observed to move actively from DIV 7 to DIV 9. The mean density of filopodia was (10.78 +/-3.78)/100 microm, (10.68 +/-2.96)/100 microm and (9.99 +/-3.67)/100 microm (P >0.05), and there were (30.18 +/-14.03)% to (87.36 +/-20.88)% filopodia were mobile (P <0.001). During DIV 7-DIV 14, the total length of dendritic branches grew from (410.74 +/-185.98) microm to (1238.21 +/-418.32)microm (P <0.001) and the number of dendritic branches increased from 18.93 +/-7.23 to 33.60 +/-10.46 (P<0.001). The density of spine was (37.17 +/-6.46)/100 microm at DIV 14. CONCLUSION: The combination of live imaging with quantitative analysis is a useful method to study dendritic morphological development in vitro, including indicators of dendritic filopodia, dendritic arborization and spines.

[Effects of thermostress on the plasma membrane permeability of desert moss Tortula desertorum examined by in-situ micro-FTIR analysis].

A technique based on Fourier transform infrared microscope (FT-IRM) was developed to detect the corresponding changes in chemical composition associated with thermostress among aging tissues of the desert moss Tortula desertorum. The results indicated that wild leaves could accelerate the rate of carbohydrate synthesis and decrease the permeability of plasma membrane during heating at 45 degrees C for 1 h. Those biological responses can alleviate the damage of heat stress, so called thermotolerance. And the ability has a positive relation to the leaf age among various wild leaves. However, the secondary protonema and leaves, cultivated in artificial incubator, were unable to adapt the change of temperature immediately and the permeability of cellular membranes was increased.

Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of intractable trigeminal neuralgia.

BACKGROUND: Percutaneous radiofrequency thermocoagulation of the trigeminal ganglion (PRTTG) is regarded as the first choice for most patients with trigeminal neuralgia (TN) because of its safety and feasibility. However, neuronavigator-guided PRTTG has been seldom reported. The purpose of this study was to assess the safety and efficacy of neuronavigator-guided PRTTG for the treatment of intractable TN. METHODS: Between January 2000 and December 2004, 54 patients with intractable TN were enrolled into this study and were randomly divided into two groups. The patients in navigation group (n = 26) underwent PRTTG with frameless neuronavigation, and those in control group (n = 28) received PRTTG without neuronavigation. Three months after the operation, the efficacy, side effects, and complications of the surgery were recorded. The patients in the control group were followed up for 10 to 54 months (mean, 34 +/- 5), and those in the navigation group were followed up for 13 to 58 months (mean, 36 +/- 7). Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data, and the log-rank test was used to compare survival curves of the two groups. RESULTS: The immediate complete pain-relief rate of the navigation group was 100%, whereas it was 95% in the control. The proportion of sustained pain-relief rates at 12, 24 and 36 months after the procedure were 85%, 77%, and 62% in the navigation group, and 54%, 40%, and 35% in the control. Recurrences in the control group were more common than that in the navigation group. Annual recurrence rate in the first and second years were 15% and 23% in the navigation group, and 46%, 60% in the control group. No side-effect and complication was noted in the navigation group except minimal facial hypesthesia. CONCLUSION: Neuronavigator-guided PRTTG is a safe and promising method for treatment of intractable TN with better short- and long-term outcomes and lower complication rate than PRTTG without neuronavigation.

[Microsurgical treatment of trigeminal neurinomas with middle fossa extradural approach].

OBJECTIVE: To investigate the effect of microsurgical treatment of trigeminal neurinomas with middle fossa extradural approach. METHODS: Between January 1996 and December 2005, 27 patients with trigeminal schwannomas were treated by middle fossa extradural approach. The clinical data were retrospectively analyzed. RESULTS: Total resection was achieved in 25 patients and subtotal resection in the other 2 patients. The cranial nerve deficits were improved in 18 patients, unchanged in 4 patients and worsened in 5 patients postoperatively. New Incomplete paralysis of cranial nerve were observed in 4 patients. Cerebrospinal fluid leakages and bacterial meningitis occurred in 2 cases, which were cured by lumber draining and antibiotic therapy. There was not operative mortality. Twenty six patients were followed up for 6 - 48 months. Tumor recurrence was found in 1 case after 40 months and was excised again. CONCLUSION: This approach can provide better exposure of these tumors and multiple working angles with minimal brain retraction and can improve the surgical results in terms of increased complete tumor resection rate and reduced complications rate.

[Synergic effects of synthesis arecoline in combination with snail-killing drugs niclosamide].

OBJECTIVE: To prove that synthetic Are combination with snail-killing drug Nic can increase the effects of snail-killing remarkably. METHODS: In indoor immersing experimentation, the experiments were divided into 4 groups, 30 snails in each group, to observe the rate of opening operculum, the rate of climbing adhesion and the rate of death at 3, 6 and 24 hours respectively. In field experimentation, we intermixed 0.1 mg/L Are with 0.2 mg/L Nic as sample as contrasted with 2 mg/L Nic and non-drug group. Immersing method (we chose three slots each size were 10 m x 2 m x 1 m.) and insufflation method (we chose three patch of bottomlands each area were 10 m x 5 m.) were used to kill snails separately and the death rate of fish, at the same time was observed. RESULTS: In the room, as we added 0.1 mg/L Are to the solution of 0.1 mg/L and 0.2 mg/L Nic separately, the opening operculum rate for 6 hours was increased from 20% and 12% to 100% and 95%, the climbing adhesion rate for 6 hours decreased from 17% and 53% to 3% and 5%, the death rate for 24 hours increased from 25% and 40% to 90% and 100%. In the field, the snails death rate in sample group and in contrastive group applied with immersing method and insufflation method for 72 hours were 95.9%, 93.3% and 100%, 95.8%; only one small fish (2 cm long) died in sample group, and all fishes died in Nic group, and all fish were alive in non-drug group. CONCLUSION: It proved that synthetic Are combination with snail-killing drug Nic might decrease Nic dosage and toxicity and increase the effects of snail-killing.

Spatiotemporal changes of the N-methyl-D-aspartate receptor subunit levels in rats with pentylenetetrazole-induced seizures.

The aim of this study was to examine the expression profiles of N-methyl-D-aspartate (NMDA) receptor subunits in rats during seizure development and kindled process induced by pentylenetetrazole (PTZ). Using quantitative Western blotting, the levels of NR1, NR2A and NR2B subunits were measured in the cortex and hippocampus of rats at different times after PTZ injection. In the early seizure developmental process, both NR1 and NR2A were markedly increased in the cortex, and NR1 was significantly increased in the hippocampus. On the other hand, in the kindled process both NR1 and NR2A decreased in the cortex and hippocampus. However, the NR2B subunit had no appreciable change in both the seizure developmental and kindled process. Therefore, these results showed that expression of NMDA receptors undergoes subunit- and region-related changes in the developmental and kindled seizure of rats induced by PTZ.

[Correlation between basic expression level of NMDA receptor NR1 subunit protein in hippocampus and learning ability in rats].

OBJECTIVE: To investigate the relationship between basic expression level of NMDA receptor NR1 subunit protein in hippocampus and learning ability of rats. METHODS: Using a novel-object recognition model and Morris water maze,the novel-object recognition ability and spatial memory of SD rats were ranked, and grouped as the high (top 20 %) and the low (bottom 20%), respectively. NR1 subunit protein levels in hippocampus were measured by quantitative immunoblotting with NR1 subunit specific antibody. RESULT: The level of NR1 subunit protein in hippocampus in the high novel-object recognition ability group was 60% (P<0.01), higher than that in the low one, and in the high spatial memory group it was 45.4 % (P<0.05), higher than that in the low one, respectively. CONCLUSION: The basic expression level of NR1 subunit protein in hippocampus is related to novel-object recognition ability and spatial memory of rats.

[Effects of pentylenetetrazol at subconvulsant and convulsant dose on NMDA receptor subunits in rats].

OBJECTIVE: To investigate the expression of N-methyl-D-asparate (NMDA) receptor subunit proteins after administration of different doses of pentylenetetrazol (PTZ). METHODS: After ip injection of a subconvulsant (35 mg/kg) and convulsant (50 mg/kg) dose of PTZ, the rats were decapitated at different time points. The levels of cortical NR1 NR2A and NR2B subunit proteins were detected by immunoblotting. RESULT: 35 mg/kg PTZ and 50 mg/kg PTZ elicited different behavioral changes (P<0.001). The NR2A subunit in the cortex significantly increased 1 h after PTZ injection (P<0.05). For the 50 mg/kg group, both the NR2A and NR2B subunits proteins increased at 1 h in the cortex and then decreased; the protein levels returned to normal after 48 h. However, NR1 subunit had no changes. CONCLUSION: The NR2 subunit is involved in PTZ-induced seizure.