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31.
Long-term potentiation (LTP) in the anterior cingulate cortex (ACC) is believed to be critical for higher brain functions including emotion, learning, memory and chronic pain. N-methyl-D-aspartate (NMDA) receptor-dependent LTP is well studied and is thought to be important for learning and memory in mammalian brains. As the downstream target of NMDA receptors, the extracellular signal-regulated kinase (ERK) in the mitogen-activated protein kinase (MAPK) cascade has been extensively studied for its involvement in synaptic plasticity, learning and memory in hippocampus. By contrast, the role of ERK in cingulate LTP has not been investigated. In this study, we examined whether LTP in ACC requires the activation of ERK. We found that P42/P44 MAPK inhibitors, PD98059 and U0126, suppressed the induction of cingulate LTP that was induced by presynaptic stimulation with postsynaptic depolarization (the pairing protocol). We also showed that cingulate LTP induced by two other different protocols was also blocked by PD98059. Moreover, we found that these two inhibitors had no effect on the maintenance of cingulate LTP. Inhibitors of c-Jun N-terminal kinase (JNK) and p38, other members of MAPK family, SP600125 and SB203850, suppressed the induction of cingulate LTP generated by the pairing protocol. Thus, our study suggests that the MAPK signaling pathway is involved in the induction of cingulate LTP and plays a critical role in physiological conditions.  相似文献   
32.
雅砻江短须裂腹鱼胚胎和卵黄囊仔鱼的形态发育   总被引:2,自引:0,他引:2  
当前短须裂腹鱼(Schizothorax wangchiachii)已被列为雅砻江和金沙江的增殖放流保护鱼类,为探讨两水系的环境差异对其早期发育产生的影响,本文以雅砻江短须裂腹鱼为研究对象,通过人工授精获得受精卵,对胚胎和早期仔鱼的形态发育特征进行了观察,并与已有报道的金沙江短须裂腹鱼胚胎与仔鱼早期发育研究进行比较。研究结果显示,雅砻江短须裂腹鱼卵径(2.70±0.02)mm,较金沙江短须裂腹鱼大0.34 mm;初孵仔鱼全长(11.36±0.22)mm,比金沙江短须裂腹鱼长2.7 mm;在水温(14±1)℃时,两水系的短须裂腹鱼胚胎发育时序基本一致,但听囊等部分功能器官的发育时序存在差异;胚胎发育历时181 h,积温2 539.98 h℃,分别比金沙江短须裂腹鱼早73 h和低1 025 h℃;出膜后1~9 d,仔鱼的鳃、口、胸鳍、尾鳍、鳔、肠道等功能器官先后形成,第9天卵黄囊吸收基本完全,与金沙江短须裂腹鱼一致。比较表明,两水系短须裂腹鱼早期发育特征基本相同,但卵径大小、孵化历时、部分器官发育时序存在一定差异,可能是二者为适应环境而做出不同的选择。  相似文献   
33.
以从光皮桦茎叶组织提取的mRNA为模板,根据其他已克隆到的阔叶类树种中4-香豆酸辅酶A连接酶(4CL)基因的同源序列设计兼并引物,进行RT—PCR扩增,获得部分基因片段,然后结合5’,3’RACE方法从光皮桦中扩增出1个4CL基因的全长cDNA序列,命名为B14CL。该基因cDNA全长为1983bp(GenBank登录号FJ410448),具有完整的开放阅读框架(69—1697bp),编码蛋白为542个氨基酸,包含一个AMP结合功能域和一个含有12个氨基酸的功能基序。与其他植物中的4CL进行同源性比对的结果显示,B14CL蛋白与东北白桦的同源性最高,达到了98%。该基因在光皮桦的根和茎中表达量较高,而在花和叶中的表达量低。  相似文献   
34.
天冬氨酸蛋白酶(aspartic proteases,APs)是一类功能多样化的酶,参与了植物大部分生理和发育过程,但其基因家族在植物中的系统分类、分子进化以及功能方面研究仍很欠缺。本研究收集整理了拟南芥和水稻中APs基因序列、分类、基因结构和染色体定位等信息,对比分析该基因家族在拟南芥和水稻中分子进化方面的差异;利用转录组数据阐明该家族基因在不同组织部位和不同发育时期的表达差异和功能分化。此外,本文还围绕花药发育的过程,细致分析了各亚家族APs基因的表达变化,推测APs在花药发育过程中的可能功能。  相似文献   
35.
Cancer remains one of the leading causes of mortal-ity and morbidity throughout the world. To a signifi-cant extent, current conventional cancer therapies are symptomatic and passive in nature. The major obstacle to the development of effective cancer therapy is be-lieved to be the absence of suffi cient specifi city. Since the discovery of the tumor-oriented homing capacity of mesenchymal stem cells (MSCs), the application of specific anticancer gene-engineered MSCs has held great potential for cancer therapies. The dual-targeted strategy is based on MSCs’ capacity of tumor-directed migration and incorporation and in situ expression of tumor-specifi c anticancer genes. With the aim of trans-lating bench work into meaningful clinical applications, we describe the tumor tropism of MSCs and their use as therapeutic vehicles, the dual-targeted anticancer potential of engineered MSCs and a putative personal-ized strategy with anticancer gene-engineered MSCs.  相似文献   
36.
37.

Microbes play key roles in diverse biogeochemical processes including nutrient cycling. However, responses of soil microbial community and functional genes to long-term integrated fertilization (chemical combined with organic fertilization) remain unclear. Here, we used pyrosequencing and a microarray-based GeoChip to explore the shifts of microbial community and functional genes in a paddy soil which received over 21-year fertilization with various regimes, including control (no fertilizer), rice straw (R), rice straw plus chemical fertilizer nitrogen (NR), N and phosphorus (NPR), NP and potassium (NPKR), and reduced rice straw plus reduced NPK (L-NPKR). Significant shifts of the overall soil bacterial composition only occurred in the NPKR and L-NPKR treatments, with enrichment of certain groups including Bradyrhizobiaceae and Rhodospirillaceae families that benefit higher productivity. All fertilization treatments significantly altered the soil microbial functional structure with increased diversity and abundances of genes for carbon and nitrogen cycling, in which NPKR and L-NPKR exhibited the strongest effect, while R exhibited the least. Functional gene structure and abundance were significantly correlated with corresponding soil enzymatic activities and rice yield, respectively, suggesting that the structural shift of the microbial functional community under fertilization might promote soil nutrient turnover and thereby affect yield. Overall, this study indicates that the combined application of rice straw and balanced chemical fertilizers was more pronounced in shifting the bacterial composition and improving the functional diversity toward higher productivity, providing a microbial point of view on applying a cost-effective integrated fertilization regime with rice straw plus reduced chemical fertilizers for sustainable nutrient management.

  相似文献   
38.
基于移动终端的稻田飞虱调查方法   总被引:2,自引:0,他引:2  
【目的】建立一种基于移动终端的稻田飞虱调查方法,以减轻测报人员劳动强度,提高稻田飞虱调查的客观性,实现稻飞虱调查结果可追溯。【方法】利用Android相机、可伸缩手持杆和装载控制相机APP的Android手机研制了稻田飞虱图像采集仪。在Android开发环境下,利用socket通信和视频编码等技术,实现Android相机的视频采集与编码模块、视频传输模块和相机命令控制模块等。利用Android NDK开发和Java web等技术,实现手机端的视频预览模块、手机控制模块、图像上传模块等。相机实时拍摄的视频将压缩成H.264格式,通过RTSP/RTP协议控制其传输至手机端。手机端通过解压缩,实现实时预览相机所拍摄的视频,并控制相机拍摄水稻茎基部飞虱图像,同时将图像传输到手机端。稻飞虱识别算法部署在云服务器上。手机端可选择稻飞虱图像上传至云服务器,云服务器运行稻飞虱自动识别算法,结果返回至手机端。【结果】基于移动终端的稻田飞虱调查方法利用手机可以实时预览相机拍摄的水稻茎基部飞虱画面,控制相机拍照。云服务器上稻飞虱自动识别算法对图像中的飞虱平均检测率为86.9%,虚警率为11.2%;对稻飞虱各虫态平均检测率为81.7%,虚警率为16.6%。【结论】基于移动终端的稻田飞虱调查方法可以便捷地采集到水稻茎基部飞虱图像,实现稻田飞虱不同虫态的识别与计数。该方法可大大减轻测报人员的劳动量,避免稻飞虱田间调查的主观性,实现稻飞虱田间调查的可追溯。  相似文献   
39.
王婧  伍龙军  徐天乐 《生命科学》2002,14(5):257-260
非NMDA受体是AMPA受体和KA受体的统称,其亚基上的胞内C末端上有很多磷酸化脱磷酸化及胞内蛋白的结合位点,这些作用位点与非NMDA受体的调控密切相关。如PKA,PKC,PKG,CaMKⅡ和PTK等蛋白激酶均可调节受体的活性,另外,胞内的一些骨架蛋白和信号蛋白也可与非NMDA受体结合而影响其功能,本文着重综述非NMDA受全的细胞内调控及其机制。  相似文献   
40.
绿洲―荒漠交错带土壤水分变化特征初步研究   总被引:36,自引:0,他引:36       下载免费PDF全文
 以甘肃省的民勤绿洲为例,选择土壤水分最为亏缺的7月,对白刺(Nitraria tangutorum)沙包不同迎风面,以及绿洲和荒漠交错地带的土壤水分进行了取样分析。结果表明,对于白刺沙包而言,其上层和深层土壤水分是迎风坡大于背风坡,中间层次(40~80 cm)则刚好相反。在绿洲与荒漠的交错带上,灌丛沙包与沙丘间低地水分变化有很大的不同,总体而言,丘间地水分含量大于灌丛沙包,但在距离绿洲406 m处,二者均出现一个土壤水分的最低值。在丘间地表层,水分变化是距离绿洲愈近,土壤含水量愈高;而深层土壤水分的变化趋  相似文献   
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