Synapse organizers are essential for the development,transmission,and plasticity of synapses.Acting as rare synapse suppressors,the MAM domain containing glycosylphosphatidylinositol anchor(MDGA)proteins contributes t...Synapse organizers are essential for the development,transmission,and plasticity of synapses.Acting as rare synapse suppressors,the MAM domain containing glycosylphosphatidylinositol anchor(MDGA)proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex.A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with autism.However,MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory synapses.Differentiating the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective strategy.To address this,we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal neurons.Here we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature hippocampus.Conditional deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials,vesicular glutamate transporter 1 intensity,and neuronal excitability.These effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter intensity.Functionally,evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic inputs.At a behavioral level,memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired,consistent with deficits in long-term potentiation in the CA3-CA1 pathway.Social affiliation,a behavioral analog of social deficits in autism,was similarly compromised.These results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits,thereby optimizing this network for plasticity,cognition,and social behaviors.展开更多
This paper addresses some of the requirements of the advance organizers and prediction activities for DDL(Data-Driv en Learning) based on multi-modal corpora for learning English as a second language.It analyzes preli...This paper addresses some of the requirements of the advance organizers and prediction activities for DDL(Data-Driv en Learning) based on multi-modal corpora for learning English as a second language.It analyzes preliminary advantages and dis advantages of using multi-modal corpora for DDL and focuses on key methodological issues related to self-guided learning and corpus operation.Pedagogical suggestions are provided on how to make the multi-modal corpora based DDL engaging in accor dance with Krashen' s Language Input Hypothesis with the assistance of advance organizers and prediction activities.展开更多
The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual ...The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL （English as a Foreign Language） learners＇ writing.展开更多
The present study investigated the impact from GOs （Graphic Organizers） upon reading comprehension ability. To this end, an OPT （Oxford Placement Test） was administered to a research population （N = 354） in orde...The present study investigated the impact from GOs （Graphic Organizers） upon reading comprehension ability. To this end, an OPT （Oxford Placement Test） was administered to a research population （N = 354） in order to homogenize it. On the basis of the test results, the population was sorted into three groups of reading-low, reading-mid, and reading-high students. Sixty participants with the lowest level of reading comprehension proficiency were randomly selected and assigned to an EG （Experimental Group） （N = 30） and a CG （Control Group） （N = 30）. Afterwards, a TOEFL （Test of English as a Foreign Language） reading comprehension pretest was administered to both groups in order to determine their current level of reading proficiency. Then, the EG received 10 successive 90-minute sessions on GOs as post-reading strategies for expository text comprehension, while the CG received the same amount of treatment on other post-reading strategies. In the end, another TOEFL reading comprehension posttest was administered to the research groups to measure their reading comprehension performance level after the treatment. The results revealed that GOs were statistically more significant and effective for the low-skilled readers than other post-reading strategies.展开更多
基金supported by the National Natural Science Foundation of China(82001203,82173819,81871012,and 81571263)the Scientific Research Fund of Zhejiang Provincial Education Department(Y201839276)+3 种基金the Scientific Research Foundation of Zhejiang University City College(X-202103)the R&D Project of Zhejiang(2022C03034)the Natural Science Foundation of Zhejiang Province(LQ23C090001)a Canada Research Chair Award(P2018-0246).
文摘Synapse organizers are essential for the development,transmission,and plasticity of synapses.Acting as rare synapse suppressors,the MAM domain containing glycosylphosphatidylinositol anchor(MDGA)proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex.A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with autism.However,MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory synapses.Differentiating the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective strategy.To address this,we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal neurons.Here we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature hippocampus.Conditional deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials,vesicular glutamate transporter 1 intensity,and neuronal excitability.These effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter intensity.Functionally,evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic inputs.At a behavioral level,memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired,consistent with deficits in long-term potentiation in the CA3-CA1 pathway.Social affiliation,a behavioral analog of social deficits in autism,was similarly compromised.These results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits,thereby optimizing this network for plasticity,cognition,and social behaviors.
文摘This paper addresses some of the requirements of the advance organizers and prediction activities for DDL(Data-Driv en Learning) based on multi-modal corpora for learning English as a second language.It analyzes preliminary advantages and dis advantages of using multi-modal corpora for DDL and focuses on key methodological issues related to self-guided learning and corpus operation.Pedagogical suggestions are provided on how to make the multi-modal corpora based DDL engaging in accor dance with Krashen' s Language Input Hypothesis with the assistance of advance organizers and prediction activities.
文摘The present study applies ＂Textual Patterns＂ like ＂general-specific＂ and ＂claim-counterclaim＂ to explore discourse coherence in Chinese students＇ English writing. The study confirms the function of the textual patterns as macro-structures for discourse interpretation and production, and proves textual patterns as effective tools in identifying and solving problems with discourse coherence in Chinese EFL （English as a Foreign Language） learners＇ writing.
文摘The present study investigated the impact from GOs （Graphic Organizers） upon reading comprehension ability. To this end, an OPT （Oxford Placement Test） was administered to a research population （N = 354） in order to homogenize it. On the basis of the test results, the population was sorted into three groups of reading-low, reading-mid, and reading-high students. Sixty participants with the lowest level of reading comprehension proficiency were randomly selected and assigned to an EG （Experimental Group） （N = 30） and a CG （Control Group） （N = 30）. Afterwards, a TOEFL （Test of English as a Foreign Language） reading comprehension pretest was administered to both groups in order to determine their current level of reading proficiency. Then, the EG received 10 successive 90-minute sessions on GOs as post-reading strategies for expository text comprehension, while the CG received the same amount of treatment on other post-reading strategies. In the end, another TOEFL reading comprehension posttest was administered to the research groups to measure their reading comprehension performance level after the treatment. The results revealed that GOs were statistically more significant and effective for the low-skilled readers than other post-reading strategies.
