Impaired cognitive map in transgenic animals relevant to Alzheimer's disease: from neurons to network / 生理学报

Alzheimer's disease (AD) is a typical cognitive disorder with an increasing incidence in recent years. AD is also one of the main causes of disability and death of the elderly in current aging society. One of the most common symptoms of AD is spatial memory impairment, which occurs in more than 60% of patients. This memory loss is closely related to the impairment of cognitive maps in the brain. The entorhinal grid cells and the hippocampal place cells are important cellular basis for spatial memory and navigation functions in the brain. Understanding the abnormal firing pattern of these neurons and their impaired coordination to neural oscillations in transgenic rodents is crucial for identifying the therapeutic targets for AD. In this article, we review recent studies on neural activity based on transgenic rodent models of AD, with a focus on the changes in the firing characteristics of neurons and the abnormal electroencephalogram (EEG) rhythm in the entorhinal cortex and hippocampus. We also discuss potential cell-network mechanism of spatial memory disorders caused by AD, so as to provide a scientific basis for the diagnosis and treatment of AD in the future.

Progress in the encoding characteristics and mechanisms of hippocampal neural assemble sequences in spatial memory / 生理学报

The formation, consolidation and retrieval of spatial memory depend on sequential firing patterns of place cells assembling in the hippocampus. Theta sequences of place cells during behavior play a role in acquisition of spatial memory, trajectory prediction and decision making. In awake rest and slow wave sleep, place cell sequences occur during the sharp wave-ripples (SWRs), called "replay", which is crucial for memory consolidation and retrieval. In this review, we summarize the functional significances of theta sequences and SWRs replay sequences and the mechanism of these sequences. We also discuss the relationship between theta and replay sequences with the formation of spatial memory. We propose the research direction in this field in future and aim to provide new ideas for related researches.

Genotypes and clinical features of 595 children with HbH disease in Guangxi, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the genotypes and clinical features of children with HbH disease in Guangxi Zhuang Autonomous Region, China.</p><p><b>METHODS</b>A total of 595 children from Guangxi were recruited. Single-tube multiplex polymerase chain reaction combined with agarose gel electrophoresis, as well as reverse dot blotting, were performed to detect the three α-globin gene deletion mutations (--(SEA), -α(3.7), and -α(4.2)) and three non-deletion mutations (Hb Westmead, Hb Constant Spring, and Hb Quong Sze) which are common in the Chinese population.</p><p><b>RESULTS</b>Among the 595 cases, five common genotypes were identified, which were --(SEA)/-α(3.7) (232 cases), --(SEA)/α(CS)α (174 cases), --(SEA)/-α(4.2) (122 cases), --(SEA)/α(WS)α (35 cases), and --(SEA)/α(QS)α (24 cases). The genotype of THAI deletion associated with α-thalassemia-2 was detected in eight cases. Six β-mutations including CD41-42, CD17-28, CD26, IVS-II-654, IVS-I-1, and CD27-28 were identified in 23 cases. All children with HbH disease had microcytic hypochromic anemia; children with HbH-CS disease had the most severe anemia, and those with HbH-WS disease had the mildest anemia.</p><p><b>CONCLUSIONS</b>Deletional HbH disease is the main type in children with HbH disease in Guangxi, and some patients also have mild beta-thalassemia. Non-deletional HbH disease shows more severe phenotype than deletional HbH disease.</p>

Analysis of chromosomal abnormalities and a report of eight new karyotypes among children in genetic counseling / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the relationship between abnormal karyotypes and clinical phenotypes among children in genetic counseling in Guangxi Zhuang Autonomous Region, China.</p><p><b>METHODS</b>We studied 601 children who visited Guangxi Zhuang Autonomous Region Women and Children Care Hospital for genetic counseling between January 2009 and July 2012. Blood samples were cultured routinely for karyotype analysis with G banding as well as clinical analysis.</p><p><b>RESULTS</b>Out of 601 patients, 329 (54.7%) had chromosomal abnormalities, and 8 new abnormal human karyotypes were found. Among 329 children with abnormal karyotypes, 317 (96.4%) had an abnormal number of chromosomes, and 12 (3.6%) had abnormal chromosomal structure. Abnormal karyotypes were clinically manifested by Down's syndrome (74.5%), growth retardation (10.9%), and mental retardation (3.0%).</p><p><b>CONCLUSIONS</b>Eight rare abnormal karyotypes were found in the study, providing new resources for the genetic studies and etiological analysis of growth retardation, mental retardation, gonadal dysgenesis, and multiple congenital anomalies in children.</p>

Association between SIRT1 gene polymorphisms and longevity of populations from Yongfu region of Guangxi / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association between SIRT1 gene polymorphisms and the longevity phenomena in Yongfu region of Guangxi. In this case-control study, 500 individuals from Yongfu region of Guangxi were recruited. The subjects were divided into a longevity group (n=223, average age=93.17 U+00B1 3.08 yr) and a healthy control group (n=277, average age=46.92 U+00B1 17.12 yr). Polymerase chain reaction-high resolution melting curve (PCR-HRM) and DNA sequencing were used to determine the allelic and genotypic frequencies of rs3758391, rs3740051, rs2273773, rs4746720 and rs10997870 polymorphisms of SIRT1 gene in the two groups. The association between above polymorphisms and longevity was assessed.</p><p><b>RESULTS</b>In the longevity group, CT genotype of the rs4746720 locus was significantly more common than CC and TT genotypes (P=0.000, OR=2.098, 95%CI:1.412-4.117). However, no significant difference was found in the allelic and genotypic frequencies of rs3758391, rs3740051 and rs2273773 between the two groups.</p><p><b>CONCLUSION</b>There is an association between rs4746720 of SIRT1 gene and longevity in Yongfu region of Guangxi.</p>

Study on the longevity related mitochondrial genome variation in Bama elderly population in Guangxi province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the human mitochondrial DNA (mtDNA) variations associated with longevity in Bama elderly population from Guangxi.</p><p><b>METHODS</b>Mitochondrial genome of 20 individuals over 96 years of age was sequenced, and seven target single nucleotide polymorphism (SNPs) were observed by comparing with the standard rCRS sequence, and two were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a larger population including 208 individuals of 90-113 years old, and 586 unrelated control individuals from Guangxi.</p><p><b>RESULTS</b>The 4824G frequency of the mtDNA4824A/G locus increased with age both in the long-lived elderly and in controls. And it was significantly higher in controls than that in long-lived population (P<0.05).</p><p><b>CONCLUSION</b>The mtDNA4824 A/G is not only an age-related locus, its mutation is also negatively correlated with longevity.</p>

Cognitive Ability and Apolipoprotein E Genotypes in Long Lived Elderly in Bama area of Guangxi / 中国心理卫生杂志

Objective:To study the relation between the distribution ofapolipoprotein E(apoE)genotypes and cognitive impairment onset in long lived elderly in Bama area in Guangxi in china.Methods:A total of 112 long lived elderly aged 90 years old and over were collected and tested with MMSE to inspect their cognitive function,and they were classified into cognition impaired group and non-impaired group according to MMSE scores.We determined the AopE genotypes by way of PCR-RFLP technique,and compared the differences of AopE allele and genotype of the two groups.Result:The cognitive disfunction was found to be 14.29% in long lived elderly in Bama area.The ApoE ? 3/? 3 genotypes have highest frequency in long-lived elderly,next is ?2/3,and ?4/4 is lowest frequency.There were significant differences of ? 4 allele frequencies between cognition impaired group and non-impaired group(P