scholarly journals Hippocampal LTP and contextual learning require surface diffusion of AMPA receptors

Nature ◽  
2017 ◽  
Vol 549 (7672) ◽  
pp. 384-388 ◽  
Author(s):  
A. C. Penn ◽  
C. L. Zhang ◽  
F. Georges ◽  
L. Royer ◽  
C. Breillat ◽  
...  
Keyword(s):  
Surface Diffusion ◽  
Ampa Receptors ◽  
Contextual Learning

scholarly journals Pharmacological modulation of AMPA receptor surface diffusion restores hippocampal synaptic plasticity and memory in Huntington’s disease

2018 ◽  
Author(s):  
Hongyu Zhang ◽  
Chunlei Zhang ◽  
Jean Vincent ◽  
Diana Zala ◽  
Caroline Benstaali ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Signaling Pathway ◽  
Surface Diffusion ◽  
Ampa Receptors ◽  
Molecular Basis ◽  
Super Resolution ◽  
Long Term Potentiation ◽  
Hippocampal Synaptic Plasticity

AbstractImpaired hippocampal synaptic plasticity is increasingly considered to play an important role in cognitive impairment in Huntington’s disease (HD). However, the molecular basis of synaptic plasticity defects is not fully understood. Combining live-cell nanoparticle tracking and super-resolution imaging, we show that dysregulation of AMPA receptors (AMPARs) surface diffusion represents a molecular basis underlying the aberrant hippocampal synaptic plasticity during HD. AMPARs surface diffusion is increased in various HD neuronal models, which results in the failure of AMPARs surface stabilization after long-term potentiation (LTP) stimuli. This appears to result from a defective brain-derived neurotrophic factor (BDNF) - tyrosine receptor kinase B (TrkB) - Ca2+/calmodulin-dependent protein kinase II (CaMKII) signaling pathway that impacts the interaction between the AMPAR auxiliary subunit stargazin and postsynaptic density protein 95 (PSD-95). Notably, the disturbed AMPAR surface diffusion is rescued, via BDNF signaling pathway and by the antidepressant tianeptine. Tianeptine also restores the impaired LTP and hippocampus-dependent memory as well as anxiety/depression-like behavior in different HD mouse models. We thus unveil a mechanistic framework underlying hippocampal synaptic and memory dysfunction and propose a new perspective in HD treatment by targeting AMPAR surface diffusion.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

Implementasi Pembelajaran Kontekstual berpendekatan Learning Community pada Bidang Studi Fiqh dalam Meningkatkan Motivasi dan Prestasi Belajar Siswa MI Mambaul Hidayah Mengelo Sooko Mojokerto

2018 ◽  
Vol 1 (2) ◽  
pp. 57
Author(s):  
Masadah Masadah
Keyword(s):  
Learning Community ◽  
Descriptive Analysis ◽  
Visual Presentation ◽  
Contextual Learning ◽  
Learning Motivation ◽  
Human Beings ◽  
Action Execution ◽  
Average Value ◽  
Community Approach ◽  
Motivation And Achievement

Education is a conscious and systematic effort not only to humanize human beings but also for human beings to realize their position as khalifatullah fil ardhi, which in turn will increasingly increase itself to be a pious, faithful, knowledgeable and virtuous man. In general the problems formulated in this research is whether Implementation of Contextual Learning with Learning Community approach can improve student's motivation and achievement in FIQH study field? How Implementation of Contextual Learning has a Learning Community approach that can improve students' motivation and achievement in FIQH? Field. This research was conducted in Mojokerto Regency, precisely at MI Mambaul Hidayah Mengelo Sooko Mojokerto. This research is a classroom action research with collaborative type. This research phase follows a model developed by Kemmis and Taggart, which is a spiral cycle that includes planning activities, action execution, observation, and reflection. The data collection techniques used are: (1) observation; (2) measurement of learning result test; and (3) documentation. Data obtained from the action are then analyzed. Qualitative data consisting of observation and documentation are analyzed qualitatively, while data collected in the form of numbers or quantitative data, simply by using descriptive analysis and visual presentation. Based on the results of research that has been implemented can be concluded that the Implementation of Contextual Learning with Learning Community approach can improve student's motivation and achievement in the field of FIQH study. From the data in the field shows that there is an increase in student learning motivation that the initial average value of pre-test of 20 increased to 24 or about 20% in cycle I, in cycle II more increased to 31 or about 55%, and in cycle III the more increased to 45 or about 125%. Level of increase between cycle I with cycle II about 29%, between cycle II with cycle III about 45%, between cycle III with cycle I about 87%. With the increase of students' learning motivation, their learning achievement also increased, whereas the average value of pre test of 6.60 increased to 6.84 or about 4% in cycle I, in cycle II more increased again to 7.75 or about 17 %, and in cycle III it increases to 8.80 or about 35%. The level of improvement between cycle I with cycle II is about 13%, between cycle II with cycle III about 15%, between cycle III with cycle I about 30%.

UPAYA MENINGKATKAN HASIL BELAJAR IPA MELALUI PENDEKATAN KONTEKSTUAL DI KELAS VI SD NEGERI 018 KUBANG JAYA KECAMATAN SIAK HULU KABUPATEN KAMPAR

2018 ◽  
Vol 2 (3) ◽  
pp. 468
Author(s):  
Zulhamdi Zulhamdi
Keyword(s):  
Data Analysis ◽  
Student Learning ◽  
Learning Outcomes ◽  
Science Learning ◽  
Student Learning Outcomes ◽  
Contextual Learning ◽  
Average Score ◽  
Baseline Score ◽  
Science Students ◽  
Student Activity

This research is based on the result of science learning of grade VI students of SD Negeri 018 Kubang JayaKecamatan Siak Hulu Kabupaten Kampar which is still very low. This study aims to improve science learningoutcomes. From the data analysis, there was an increase of both teacher activity, student activity, and studentlearning result. The teacher activity at the 1st cycle meeting percentage was 70% (good) and at the 2nd meetingincreased 5% to 75% (good). In the second cycle of the meeting 3 teacher activities increased 10% from 75%(good) to 85% (very good) and at meeting 4 increased 10% from 85% (very good) to 95% (very good). Judgingfrom the student activity also increased from the 1st meeting of cycle I was 65% (enough) and at meeting 2increased 15% to 80% (good). In the second cycle of meeting 3 it increases 5% from 80% (good) to 85% (verygood) and at meeting 4 increases 10% from 85% (very good) to 95% (very good). Judging from the results of thestudents also experienced preningkat, from the average score of students on a basic score of 62.78. after the firstcycle the student's average score increased to 79.44 with an increase of 16.66 points from the baseline score. Inthe second cycle student learning outcomes also increased as much as 11.67 points from cycle I with averagestudent's grade 91.11. From the data analysis there is an increase both from teacher activity, student activity,and student learning outcomes. It can be concluded that the advancement of contextual learning can improve thelearning outcomes of science students of grade 6 of SD Negeri 018 Kubang Jaya Kecamatan Siak HuluKabupaten Kampar.

Blue Sapphire with Partial Red Surface Diffusion

2020 ◽  
Vol 37 (1) ◽  
pp. 23-24
Author(s):  
Bear Williams ◽  
Cara Williams ◽  
Charles I. Carmona
Keyword(s):  
Surface Diffusion
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