1.Statistical physics approaches to neuronal network dynamics.
Acta Physiologica Sinica 2011;63(5):453-462
We review a statistical physics approach for reduced descriptions of neuronal network dynamics. From a network of all-to-all coupled, excitatory integrate-and-fire neurons, we derive a (2+1)-D advection-diffusion equation for a probability distribution function, which describes neuronal population dynamics. We further show how to derive a (1+1)-D kinetic equation, using a moment closure scheme, without introducing any new parameters to the system. We demonstrate the numerical accuracy of our kinetic theory by comparing its results to Monte Carlo simulations of the full integrate-and-fire neuronal network.
Animals
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Computer Simulation
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Humans
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Models, Neurological
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Monte Carlo Method
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Nerve Net
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physiology
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Neural Networks (Computer)
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Neurons
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physiology
2.Computational modeling of the dynamics of simple and complex cells in primary visual cortex.
Acta Physiologica Sinica 2011;63(5):401-411
We review our work on computational modeling of the mammalian visual cortex. In particular, we explain the network mechanism of how simple and complex cells arise in a large scale neuronal network model of primary visual cortex. The simple cells are so-called because they respond approximately linearly to visual stimulus, whereas the complex cells exhibit nonlinear response to visual stimulation. Our model reproduces qualitatively the experimentally observed distributions of simple and complex cells.
Animals
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Computer Simulation
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Humans
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Models, Neurological
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Nerve Net
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physiology
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Neurons
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physiology
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Photic Stimulation
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Visual Cortex
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cytology
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physiology
3.The cystic fibrosis transmembrane conductance regulator Cl⁻ channel: a versatile engine for transepithelial ion transport.
Hongyu LI ; Zhiwei CAI ; Jeng-Haur CHEN ; Min JU ; Zhe XU ; David N SHEPPARD
Acta Physiologica Sinica 2007;59(4):416-430
The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ATP-binding cassette (ABC) transporter superfamily that forms a Cl(-) channel with complex regulation. CFTR is composed of five domains: two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs) and a unique regulatory domain (RD). The MSDs assemble to form a low conductance (6-10 pS) anion-selective pore with deep intracellular and shallow extracellular vestibules separated by a selectivity filter. The NBDs form a head-to-tail dimer with two ATP-binding sites (termed sites 1 and 2) located at the dimer interface. Anion flow through CFTR is gated by the interaction of ATP with sites 1 and 2 powering cycles of NBD dimer association and dissociation and hence, conformational changes in the MSDs that open and close the channel pore. The RD is an unstructured domain with multiple consensus phosphorylation sites, phosphorylation of which stimulates CFTR function by enhancing the interaction of ATP with the NBDs. Tight spatial and temporal control of CFTR activity is achieved by macromolecular signalling complexes in which scaffolding proteins colocalise CFTR and plasma membrane receptors with protein kinases and phosphatases. Moreover, a macromolecular complex composed of CFTR and metabolic enzymes (a CFTR metabolon) permits CFTR activity to be coupled tightly to metabolic pathways within cells so that CFTR inhibition conserves vital energy stores. CFTR is expressed in epithelial tissues throughout the body, lining ducts and tubes. It functions to control the quantity and composition of epithelial secretions by driving either the absorption or secretion of salt and water. Of note, in the respiratory airways CFTR plays an additional important role in host defence. Malfunction of CFTR disrupts transepithelial ion transport leading to a wide spectrum of human disease.
Cystic Fibrosis Transmembrane Conductance Regulator
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physiology
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Epithelium
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physiology
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Humans
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Ion Transport
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Phosphorylation
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Protein Interaction Domains and Motifs
4.hCD47 induces immune tolerance of human macrophages to porcine endothelial cells
Wenbao HU ; Dengke PAN ; David K.C.Cooper ; Zhiming CAI ; Lisha MOU
Organ Transplantation 2019;10(2):165-
Objective To investigate the effect of human CD47 (hCD47) in inducing the immune tolerance of human macrophages to porcine endothelial cells. Methods The porcine iliac endothelial cell (PIEC) transfected with pCDH-hCD47-FLAG plasmid was assigned into the pCDH-hCD47 group, PIEC transfected with pCDH-FLAG empty vector plasmid was assigned into the pCDH group, PIEC transfected with hCD47-dN was assigned into the pCDH-hCD47-dN group and human umbilical vein endothelial cell (HUVEC) was assigned into the positive control group. The cells were co-cultured with human macrophages to detect and analyze the phosphorylation of signal regulatory protein α (SIRPα) and the killing effect of human macrophages on PIEC. Furthermore, porcine arteriae endothelial cell (PAEC) was isolated from GT-/- and GT-/-/ hCD 47 gene editing pigs to analyze the phosphorylation of SIRPα and the killing effect of human macrophages on PAEC. Results The pCDH group cells could not induce the phosphorylation of SIRPα, whereas the pCDH-hCD47 group cells could activate the phosphorylation of SIRPα after 10 min co-culture with human macrophages, and the degree of phosphorylation of SIRPα was increased with the prolongation of the co-culture time. The pCDH-hCD47-dN group cells failed to activate the phosphorylation of SIRPα. Human macrophages exerted significant effect on killing the pCDH group cells. The pCDH-hCD47 group cells could evidently inhibit the killing effect of human macrophages (
5.Linkage analysis of susceptibility genes for familial schizophrenia on chromosome 1 in Chinese population.
Guiqing CAI ; Xinyao WU ; Tao LI ; David A COLLIER ; Xiehe LIU ; Bingjian FENG ; Hong DENG ; Dayue TONG ; Jianjin LI ; Jinghua OU
Chinese Journal of Medical Genetics 2002;19(6):491-494
OBJECTIVETo explore the molecular genetic relationship between chromosome 1 and susceptibility genes for familial schizophrenia in Chinese population.
METHODSA genome scanning was conducted in 32 multiplex pedigrees from Chinese population by using 29 microsatellite markers on chromosome 1.
RESULTSMultipoint parametric analysis detected a maximum heterogenicity Lod of 1.70 at 262.52 cM under a recessive model; multipoint non-parametric analysis detected a maximum non-parameter linkage (NPL) of 1.71 (P=0.046) at 262.52 cM, then 1.37 (P=0.086) at 149.70 cM, corresponding to marker D1S206 and D1S425 respectively.
CONCLUSIONThese results give further supports to the presence of susceptibility genes on chromosome 1q for familial schizophrenia.
Adult ; China ; Chromosome Mapping ; Chromosomes, Human, Pair 1 ; genetics ; Family Health ; Female ; Genetic Linkage ; Genetic Predisposition to Disease ; genetics ; Humans ; Lod Score ; Male ; Microsatellite Repeats ; Middle Aged ; Models, Genetic ; Pedigree ; Schizophrenia ; genetics
6.A linkage analysis of quantitative trait loci for familial schizophrenia on chromosome 1.
Guiqing CAI ; Xinyao WU ; Tao LI ; David A COLLIER ; Xiehe LIU ; Bingjian FENG ; Hong DENG ; Dayue TONG ; Jianjin LI ; Jinghua OU
Chinese Journal of Medical Genetics 2002;19(4):281-284
OBJECTIVETo explore the molecular genetic relationship between chromosome 1 and quantitative trait loci for familial schizophrenia.
METHODSA series of assessment scales included positive and negative syndrome scale (PANSS), global assessment of functional scale (GAFS), premorbid schizoid and schizotypal traits scale (PSST), premorbid social adjustment scale (PSA) were applied to quantify the phenotypes of schizophrenia. Non-parametric linkage analysis of quantitative traits was conducted in 32 multiplex pedigrees with schizophrenia by using 29 microsatellite makers on chromosome 1.
RESULTSHaseman-Elston quantitative trait analysis detected a maximum Traditional H-E Lods of 1.73 and a maximum EH H-E Lods of 1.65 of negative symptoms (PANSS-N ) at 147.64 cM, which was overlapped to the positive region of 1q21-23 in qualitative linkage analysis.
CONCLUSIONThe results suggest there might be an independent quantitative trait locus of negative symptoms on 1q21-23 for familial schizophrenia.
Chromosomes, Human, Pair 1 ; genetics ; Family Health ; Genetic Linkage ; Humans ; Lod Score ; Microsatellite Repeats ; Quantitative Trait, Heritable ; Schizophrenia ; genetics
7.Species Diversity and Seasonal Distribution of Culicoides spp. (Diptera: Ceratopogonidae) in Jeju-do, Republic of Korea.
Heung Chul KIM ; Glenn A BELLIS ; Myung Soon KIM ; Terry A KLEIN ; David GOPURENKO ; Du Cheng CAI ; Hyun Ji SEO ; In Soo CHO ; Jee Yong PARK
The Korean Journal of Parasitology 2015;53(4):501-506
Biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae) were collected by Mosquito Magnet(R) and black light traps at 5 sites on Jeju-do, Republic of Korea (Korea), from May-November 2013 to determine species diversity and seasonal distribution. A total of 4,267 specimens were collected, of which 99.9% were female. The most common species was Culicoides tainanus (91.8%), followed by C. lungchiensis (7.2%) and C. punctatus (0.6%), while the remaining 4 species accounted for <0.5% of all Culicoides spp. that were collected. High numbers of C. tainanus were collected in May, followed by decreasing numbers through August, and then increasing numbers through November when surveillance was terminated. Peak numbers of C. lungchiensis were collected during September, with low numbers collected from May-August and October-November. The presence of C. lungchiensis in Korea was confirmed by morphological and molecular analyses.
Animals
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*Biodiversity
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Ceratopogonidae/classification/*growth & development
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Female
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Insect Vectors/classification/*growth & development
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Male
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Phylogeny
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Republic of Korea
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Seasons
8.Glucagon-like peptide 1 improves learning and memory abilities of rats with type 2 diabetes.
Zhao-Guang TAN ; ; Wei-Hong GAO ; Xiang-Sheng CAI ; Fang WANG ; Hong-Xiang HUI
Journal of Southern Medical University 2016;36(10):1345-1351
OBJECTIVETo investigate the effect of glucagon-like peptide 1 (GLP-1) on cognitive dysfunction in diabetic rats.
METHODSMale SD rats were randomly divided into normal control group, diabetes mellitus (DM) group, and GLP-1 treatment group. Rat models of type 2 diabetes were established by high-sugar and high-fat feeding and streptozotocin (STZ) injection, and 25 days after the onset of diabetes, GLP-1 was infused in GLP-1 treatment group at the rate of 30 pmol·kg·minvia a subcutaneous osmotic pump for 7 days. The learning and cognitive ability of the rats was assessed with Morris water maze test, and the expression of cognition-related genes in the hippocampus tissue was detected with real-time PCR, Western blotting and immunohistochemical staining.
RESULTSCompared with the normal control group, the diabetic rats showed significantly decreased learning and memory abilities (P<0.05) with increased hippocampal expressions of APP, BACE1, Arc, ERK1/2, PKA, and PKC mRNAs (P<0.05) and Arc protein. Compared with diabetic rats, GLP-1-treated rats showed significantly improvements in the learning and memory function (P<0.05) with decreased expressions of APP, BACE1, Arc, ERK1/2, and PKA mRNAs (P<0.05) and Arc protein.
CONCLUSIONGLP-1 can improve cognitive dysfunctions in diabetic rats possibly by regulating the PKC, PKA, and ERK1/2 pathways and inhibiting Arc expression in the hippocampus.
Animals ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetes Mellitus, Type 2 ; drug therapy ; Glucagon-Like Peptide 1 ; pharmacology ; Hippocampus ; drug effects ; Learning ; drug effects ; Male ; Memory ; drug effects ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Streptozocin
9.Variation of sexual dimorphism and asymmetry in disease expression of inflammatory arthritis among laboratory mouse models with different genomic backgrounds
Wei DONG ; Cheng TIAN ; Z. Galvin LI ; David BRAND ; Yanhong CAO ; Xiaoyun LIU ; Jiamin MA ; Andy CHAI ; Linda K. MYERS ; Jian YAN ; Karen HASTY ; John STUART ; Yan JIAO ; Weikuan GU ; Xiaojun CAI
Laboratory Animal Research 2023;39(4):402-410
Sex difference has shown in the arthritis diseases in human population and animal models. We investigate how the sex and symmetry vary among mouse models with different genomic backgrounds. Disease data of sex and limbs accumulated in the past more than two decades from four unique populations of murine arthritis models were analyzed. They are (1) interleukin-1 receptor antagonist (IL-1ra) deficient mice under Balb/c background (Balb/c KO); (2) Mice with collagen II induced arthritis under DBA/1 background; (3) Mice with collagen II induced arthritis under C57BL/6 (B6) background and (4) A F2 generation population created by Balb/c KO X DBA/1 KO.Our data shows that there is a great variation in sexual dimorphism for arthritis incidence and severity of arthritis in mice harboring specific genetic modifications. For a F2 population, the incidence of arthritis was 57.1% in female mice and 75.6% in male mice. There was a difference in severity related to sex in two populations: B6.DR1/ B6.DR4 (P < 0.001) and F2 (P = 0.023) There was no difference Balb/c parental strain or in collagen-induced arthritis (CIA) in DBA/1 mice. Among these populations, the right hindlimbs are significantly higher than the scores for the left hindlimbs in males (P < 0.05). However, when examining disease expression using the collagen induced arthritis model with DBA/1 mice, sex-dimorphism did not reach statistical significance, while left hindlimbs showed a tendency toward greater disease expression over the right. Sexual dimorphism in disease expression in mouse models is strain and genomic background dependent. It sets an alarm that potential variation in sexual dimorphism among different racial and ethnic groups in human populations may exist. It is important to not only include both sexes and but also pay attention to possible variations caused by disease expression and response to treatment in all the studies of arthritis in animal models and human populations.