[서평]「The Unified Modeling Language User Guide」

Mounting evidence suggests that acute and chronic stress, especially the stress-induced release of glucocorticoids, induces changes in glutamate neurotransmission in the prefrontal cortex and the hippocampus, thereby influencing some aspects of cognitive processing. In addition, dysfunction of glutamatergic neurotransmission is increasingly considered to be a core feature of stress-related mental illnesses. Recent studies have shed light on the mechanisms by which stress and glucocorticoids affect glutamate transmission, including effects on glutamate release, glutamate receptors and glutamate clearance and metabolism. This new understanding provides insights into normal brain functioning, as well as the pathophysiology and potential new treatments of stress-related neuropsychiatric disorders.

/pdf/the-stressed-synapse-the-impact-of-stress-and-28jxfa3vve.pdf

The stressed synapse: the impact of stress and glucocorticoids on glutamate transmission

Towards a glutamate hypothesis of depression: an emerging frontier of neuropsychopharmacology for mood disorders.

Activity-dependent changes in the strength of excitatory synapses are a cellular mechanism for the plasticity of neuronal networks that is widely recognized to underlie cognitive functions such as learning and memory. AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid)-type glutamate receptors (AMPARs) are the main transducers of rapid excitatory transmission in the mammalian CNS, and recent discoveries indicate that the mechanisms which regulate AMPARs are more complex than previously thought. This review focuses on recent evidence that alterations to AMPAR functional properties are coupled to their trafficking, cytoskeletal dynamics and local protein synthesis. These relationships offer new insights into the regulation of AMPARs and synaptic strength by cellular signalling.

Regulatory mechanisms of AMPA receptors in synaptic plasticity

Evolution, structure, and activation mechanism of family 3/C G-protein-coupled receptors.

Over the past few years, there has been a quiet revolution in display manufacturing technology. One that is only comparable in scope to that of the invention of the first LCD, which led to DynaBook and the modern laptop. E-ink electrophoretic pixel technology, combined with advances in organic thin-film circuit substrates, have led to displays that are so thin and flexible they are beginning to resemble paper. Soon displays will completely mimic the high contrast, low power consumption and flexibility of printed media. As with the invention of the first LCD, this means we are on the brink of a new paradigm in computer user interface design: one in which computers can have any organic form or shape. One where any object, no matter how complex, dynamic or flexible its structure, may display information. One where the deformation of shape is a main source of input.

Organic user interfaces: designing computers in any way, shape, or form

In this paper, we present Paper Windows, a prototype windowing environment that simulates the use of digital paper displays. By projecting windows on physical paper, Paper Windows allows the capturing of physical affordances of paper in a digital world. The system uses paper as an input device by tracking its motion and shape with a Vicon Motion Capturing System. We discuss the design of a number of interaction techniques for manipulating information on paper displays.

/pdf/paper-windows-interaction-techniques-for-digital-paper-4e0ycu9mdx.pdf

Paper windows: interaction techniques for digital paper

Background: The stress hormone corticosterone has the ability both to enhance and suppress synaptic plasticity and learning and memory processes. However, until today there is very little known about the molecular mechanism that underlies the bidirectional effects of stress and corticosteroid hormones on synaptic efficacy and learning and memory processes. In this study we investigate the relationship between corticosterone and AMPA receptors which play a critical role in activity-dependent plasticity and hippocampal-dependent learning. Methodology/Principal Findings: Using immunocytochemistry and live cell imaging techniques we show that corticosterone selectively increases surface expression of the AMPAR subunit GluR2 in primary hippocampal cultures via a glucocorticoid receptor and protein synthesis dependent mechanism. In agreement, we report that corticosterone also dramatically increases the fraction of surface expressed GluR2 that undergo lateral diffusion. Furthermore, our data indicate that corticosterone facilitates NMDAR-invoked endocytosis of both synaptic and extra-synaptic GluR2 under conditions that weaken synaptic transmission. Conclusion/Significance: Our results reveal that corticosterone increases mobile GluR2 containing AMPARs. The enhanced lateral diffusion properties can both facilitate the recruitment of AMPARs but under appropriate conditions facilitate the loss of synaptic AMPARs (LTD). These actions may underlie both the facilitating and suppressive effects of corticosteroid hormones on synaptic plasticity and learning and memory and suggest that these hormones accentuate synaptic efficacy.

/pdf/corticosterone-alters-ampar-mobility-and-facilitates-4lo6ntn5bm.pdf

Corticosterone alters AMPAR mobility and facilitates bidirectional synaptic plasticity.

With the proliferation of flexible displays and the advances in smart materials, it is now possible to create interactive devices that are not only flexible but can reconfigure into any shape on demand. Several Human Computer Interaction (HCI) and robotics researchers have started designing, prototyping and evaluating shape-changing devices, realising, however, that this vision still requires many engineering challenges to be addressed. On the material science front, we need breakthroughs in stable and accessible materials to create novel, proof-of-concept devices. On the interactive devices side, we require a deeper appreciation for the material properties and an understanding of how exploiting material properties can provide affordances that unleash the human interactive potential. While these challenges are interesting for the respective research fields, we believe that the true power of shape-changing devices can be magnified by bringing together these communities. In this paper we therefore present a review of advances made in shape-changing materials and discuss their applications within an HCI context.

/pdf/hci-meets-material-science-a-literature-review-of-morphing-4u6ozz9x8i.pdf

HCI meets Material Science: A Literature Review of Morphing Materials for the Design of Shape-Changing Interfaces

Activity-dependent changes in ionotropic glutamate receptors at the postsynaptic membrane are well established and this regulation plays a central role in the expression of synaptic plasticity. However, very little is known about the distributions and regulation of ionotropic receptors at presynaptic sites. To determine if presynaptic receptors are subject to similar regulatory processes we investigated the localisation and modulation of AMPA (GluR1, GluR2, GluR3) and kainate (GluR6/7, KA2) receptor subunits by ultrasynaptic separation and immunoblot analysis of rat brain synaptosomes. All of the subunits were enriched in the postsynaptic fraction but were also present in the presynaptic and non-synaptic synaptosome fractions. AMPA stimulation resulted in a marked decrease in postsynaptic GluR2 and GluR3 subunits, but an increase in GluR6/7. Conversely, GluR2 and GluR3 increased in the presynaptic fraction whereas GluR6/7 decreased. There were no significant changes in any of the compartments for GluR1. NMDA treatment decreased postsynaptic GluR1, GluR2 and GluR6/7 but increased presynaptic levels of these subunits. NMDA treatment did not evoke changes in GluR3 localisation. Our results demonstrate that presynaptic and postsynaptic subunits are regulated in opposite directions by AMPA and NMDA stimulation.

Ultrastructural localisation and differential agonist-induced regulation of AMPA and kainate receptors present at the presynaptic active zone and postsynaptic density.

David Holman

Papers

Organic user interfaces: designing computers in any way, shape, or form

Paper windows: interaction techniques for digital paper

Corticosterone alters AMPAR mobility and facilitates bidirectional synaptic plasticity.

HCI meets Material Science: A Literature Review of Morphing Materials for the Design of Shape-Changing Interfaces

Ultrastructural localisation and differential agonist-induced regulation of AMPA and kainate receptors present at the presynaptic active zone and postsynaptic density.