Spatial exploration induces a persistent reversal of long-term potentiation in rat hippocampus

Experience-dependent long-lasting increases in excitatory synaptic transmission in the hippocampus are believed to underlie certain types of memory(1-3). Whereas stimulation of hippocampal pathways in freely moving rats can readily elicit a long-term potentiation (LTP) of transmission that may last for weeks, previous studies have failed to detect persistent increases in synaptic efficacy after hippocampus-mediated learning(4-6). As changes in synaptic efficacy are contingent on the history of plasticity at the synapses(7), we have examined the effect of experience-dependent hippocampal activation on transmission after the induction of LTP, We show that exploration of a new, non-stressful environment rapidly induces a complete and persistent reversal of the expression of high-frequency stimulation-induced early-phase LTP in the CA1 area of the hippocampus, without affecting baseline transmission in a control pathway. LTP expression is not affected by exploration of familiar environments. We found that spatial exploration affected LTP within a defined time window because neither the induction of LTP nor the maintenance of long-established LTP was blocked. The discovery of a novelty-induced reversal of LTP expression provides strong evidence that extensive long-lasting decreases in synaptic efficacy may act in tandem with enhancements at selected synapses to allow the detection and storage of new information by the hippocampus.

Mitochondrial DNA sequence diversity and origin of Chinese domestic yak

In order to clarify the origin and genetic diversity of yak in China, we analysed mitochondrial DNA (mtDNA) control region sequences (similar to 891 bp) in 52 individuals from four domestic yak (Poephagus grunniens) breeds, as well as from a hybrid betwee

无裂栉江珧种内同工酶表型差异的比较研究

采用垂直板聚丙烯酰胺梯度凝胶电泳对 4种不同类型无裂栉江珧Atrinapectinata的肾脏、后闭壳肌和鳃组织进行了酯酶 (EST)、过氧化物歧化酶 (SOD)、乳酸脱氢酶 (LDH)、苹果酸脱氢酶 (MDH)、苹果酸酶 (ME) 5种同工酶的比较研究。结果表明这 4种类型的酶谱表达有差异 ,特别是肾组织的EST ,后闭壳肌的EST、SOD和鳃组织的SOD、MDH的酶谱表型差异明显 ,其特征谱带可作为区别无裂栉江珧种内差异的一种分子标记。

Nitrite utilization by Chaetoceros muelleri under elevated CO2 concentration

Chaetoceros muelleri (Lemn.) was cultured with nitrite (NO2-) or nitrate (NO3-) as the sole nitrogen source and aerated with air or with CO2-enriched air. Cells of C. muelleri excreted into the medium nitrite produced by reduction of nitrate when grown with 100 mu M NaNO3 as nitrogen source. Accordingly, NO2- concentration reached 10.4 mu M after 95 h at the low CO2 condition (aerated with air); while the maximum NO2- concentration was only around 2.0 mu M at the high CO2 condition (aerated with 5% CO2 in air), furthermore, after 30 h it decreased to no more than 1.0 mu M. NO2- was almost assimilated in 80 h when C. muelleri was cultured at the high CO2 condition with 100 mu M NaNO2 as sole nitrogen source. At the high CO2 condition, after 3 h the activity of nitrite reductase was as much as 50% higher than that at the low CO2 condition. It was indicated that enriched CO2 concentration could inhibit nitrite excretion and enhance nitrite assimilation by cells. Therefore, aeration with enriched CO2 might be an effective way to control nitrite content in aquaculture systems.

Cancer subtypes recognition and its gene expression profiles analysis based on geometrical learning

The accurate recognition of cancer subtypes is very significant in clinic. Especially, the DNA microarray gene expression technology is applied to diagnosing and recognizing cancer types. This paper proposed a method of that recognized cancer subtypes based on geometrical learning. Firstly, the cancer genes expression profiles data was pretreated and selected feature genes by conventional method; then the expression data of feature genes in the training samples was construed each convex hull in the high-dimensional space using training algorithm of geometrical learning, while the independent test set was tested by the recognition algorithm of geometrical learning. The method was applied to the human acute leukemia gene expression data. The accuracy rate reached to 100%. The experiments have proved its efficiency and feasibility.

研究所的专利技术开发与实施工作

自专利法实施以来，我所的专利工作不断发展，为保护本所的科研成果，维护本所技术权益，提高技术经济效益，发挥了积极的作用。截至目前为止，我所申请专利共24项，其中申请发明专利8项，实用新型16项，共有8项被授予专利权，其中有一项获得美国专利和欧洲专利，另有3项已经公布。在我所批准或申请的专利项目中，本单位实施或许可他人实施的有18项，实施率达到78%，另有一项已签订了意向转让技术合同。在实

非对称长法布里-伯里腔光调制特性分析及高对比度GaAs/AlGaAs调制器

国家自然科学基金