Developmental changes in expression, subcellular distribution, and function of Drosophila N-cadherin, guided by a cell-intrinsic program during neuronal differentiation

Cell adhesion molecules (CAMs) perform numerous functions during neural development. An individual CAM can play different roles during each stage of neuronal differentiation; however, little is known about how such functional switching is accomplished. Here we show that Drosophila N-cadherin (CadN) is required at multiple developmental stages within the same neuronal population and that its sub-cellular expression pattern changes between the different stages. During development of mushroom body neurons and motoneurons, CadN is expressed at high levels on growing axons, whereas expression becomes downregulated and restricted to synaptic sites in mature neurons. Phenotypic analysis of CadN mutants reveals that developing axons require CadN for axon guidance and fasciculation, whereas mature neurons for terminal growth and receptor clustering. Furthermore, we demonstrate that CadN downregulation can be achieved in cultured neurons without synaptic contact with other cells. Neuronal silencing experiments using Kir_2.1 indicate that neuronal excitability is also dispensable for CadN downregulation in vivo. Interestingly, downregulation of CadN can be prematurely induced by ectopic expression of a nonselective cation channel, dTRPA1, in developing neurons. Together, we suggest that switching of CadN expression during neuronal differentiation involves regulated cation influx within neurons

In a contemporary tearoom--placement of ceramics : investigating contexts of raku ceramics in space and time

My thesis study investigates exclusive spaces for raku in contemporary life and time. Myexhibition focuses a modern tearoom that has modified its traditional Japanese source. Thesealterations are based on my discoveries of how raku is made and displayed in the United States.Almost thirty years, I have studied Sado, the traditional Japanese tea ceremony, that isdefined by a formal protocol established by the tea master Sen-no Rikyu in the sixteenth century,which included a raku tea bowl as a centerpiece. While some tearooms may be gold plated andothers made of rough materials, it is primarily the presence of a raku tea bowl that establishes thespace as a tearoom. Traditionally in Japan, a raku tea bowl is hand built and oxidation-fired. It isnever used for mundane purposes because of the value of the bowls most of which come fromthe exclusive workshops of Japan’s Raku family that has been making them for centuries.So, it surprised me greatly to see American raku pieces be reduction fired and result incolorful and shiny vessels. I explored this American raku method in the first semester of myMFA program and then I struggled with the subsequent placement of these raku pieces thatseemed alien in their inclusion in a traditional Sado context.As I began studying exhibiting practices of objects by particular minimalist artists in the1960s such as Carl Andre and Donald Judd, I saw a link between their simple and often monomedia work and that of a raku tea bowl in a traditional tearoom. Eva Hesse’s feminizedobjects also inspired me to consider how the tea ceremony and tearoom (which are both maledominatedphenomena) could be softened through use of specific materials. English ceramicist,Edmund de Waal’s works also allowed me consider the tactility of raku objects and how theymight be exhibited. My special interest in this artist is due to his repetition and placement ofceramic pieces. Because ceramics are deeply associated with eating utensils, they are oftenplaced in cabinets. However, de Waal plays with this pre-established grammar of display for hiswork. The manner in which he displays his ceramics is humble and sometimes even obscured bythe display units, but it also stands aloof from worldly things. I have tried to employ some ofthese ideas in my tearoom.I am viewing my tearoom as a mixed media sculpture. I have decided to construct it withfabric, metal and concrete blocks instead of using typical Japanese architectural materials such aswood, paper and clay. These alterations match my contemporary American lifestyle, but alsoadhere to some traditional Japanese protocols. Ultimately, I am proposing a new venue forviewing raku—one that seems functional but is only for viewing.An underlying philosophy of my installation work and one that is key to Sado is theconcept of ichi-go-ichi-e. This Japanese term is often translated as ‘one time, one meeting in alifetime.’ The way of tea is about the impermanence of any occasion in which entities meet.Tearooms (like raku bowls) may be moved and re-used but the nuances of each ceremony implythat nothing can truly be duplicated. My work both reveres and plays with this traditionalJapanese art form, and in so doing, I am asking viewers to see it in a new perspective. I usemass-produced materials to create my sculptures. My tearoom is housed within a commercial space in the United States, and seeks to be personally comfortable. Adjacent objects outside the tearoom are thoughtfully arranged so as to engage the viewer; they are all derived from materialsthat I found in junkyards. I hope viewers will begin to see an artistic logic in my installation

Molecular Remodeling of the Presynaptic Active Zone of Drosophila Photoreceptors via Activity-Dependent Feedback

SummaryNeural activity contributes to the regulation of the properties of synapses in sensory systems, allowing for adjustment to a changing environment. Little is known about how synaptic molecular components are regulated to achieve activity-dependent plasticity at central synapses. Here, we found that after prolonged exposure to natural ambient light the presynaptic active zone in Drosophila photoreceptors undergoes reversible remodeling, including loss of Bruchpilot, DLiprin-α, and DRBP, but not of DSyd-1 or Cacophony. The level of depolarization of the postsynaptic neurons is critical for the light-induced changes in active zone composition in the photoreceptors, indicating the existence of a feedback signal. In search of this signal, we have identified a crucial role of microtubule meshwork organization downstream of the divergent canonical Wnt pathway, potentially via Kinesin-3 Imac. These data reveal that active zone composition can be regulated in vivo and identify the underlying molecular machinery

Difference of high-light stress sensitivity in the two firs, Abies mariesii and Abies veitchii, in early spring

Abies veitchii and Abies mariesii are dominant species at the tree-line in Central Japan. Recently, we observed needle death, probably due to photodamage of the photosynthetic apparatus at the tree-limit during March-April. A. veitchii survives winter without any needle death due to photodamage at the tree-line. However, there is no conspicuous damage between the two species because this phenomenon is only observed at the tree-limit. In this study, we examined the difference in winter down-regulation of PS II between A. veitchii and A. mariesii and observed the following results: In March, (1) Fv/Fm of both species was about 0.1, showing the photochemical efficiency being severely inhibited. (2) The de-epoxidation state, expressed as [(A+Z)/(V+A+Z)], was about 0.35 for both species. (3) Chlorophyll (Chl) content of A. veitchii was much less than that of A. mariesii and Pchlide was found only in A. veitchii. In April, (1) Fv/Fm increased and [(A+Z)/(V+A+Z)] decreased for both species. (2) Chl content of A. veitchii increased by four-fold while Pchlide nearly dissappeared. These results indicate the following: During cold periods, most of Chl of A. veitchii may have been converted to Pchlide which is easily re-converted to Chl in spring, an intermediate of Chl biosynthesis. Winter conversion from Chl to Pchlide in A. veitchii may provide effective protection from photodamage of the photosynthetic apparatus. Furthermore, this may explain the higher ability of A. veitchii to prevent photodamage compared to A. mariesii

A screen of cell-surface molecules identifies leucine-rich repeat proteins as key mediators of synaptic target selection

In Drosophila embryos and larvae, a small number of identified motor neurons innervate body wall muscles in a highly stereotyped pattern. Although genetic screens have identified many proteins that are required for axon guidance and synaptogenesis in this system, little is known about the mechanisms by which muscle fibers are defined as targets for specific motor axons. To identify potential target labels, we screened 410 genes encoding cell-surface and secreted proteins, searching for those whose overexpression on all muscle fibers causes motor axons to make targeting errors. Thirty such genes were identified, and a number of these were members of a large gene family encoding proteins whose extracellular domains contain leucine-rich repeat (LRR) sequences, which are protein interaction modules. By manipulating gene expression in muscle 12, we showed that four LRR proteins participate in the selection of this muscle as the appropriate synaptic target for the RP5 motor neuron

Learning about View of Life and Death, Especially from Children’s Death Caused by Natural Disasters in the City of Manado, Province of North Sulawesi,Indonesa

This is a study conducted by our research group about the psychological background of local people in Manado,Indonesia. Interviews were made to a group of locals concerning their approach to death and consequent state of mind focused on their religious beliefs on Obon festival,conversation with spirits,reincarnation and the influence of holy men. We recognized the fantasy they believed that spirit comes back from afterworld in the ceremony. In addition,we understood the event that spirit returns from afterworld once a year and“offering” is common sense. However,these custom had difference depended on regions and their social rank. As a result,these local people were difficult to share the common sense about the event. Reporting to spirit and conversation to spirit were common events in whole regions in Indonesia,but the quality might be different. Especially,idea about reincarnation was modified among young and old generations.調査・事例等報

Loss of axonal mitochondria promotes tau-mediated neurodegeneration and Alzheimer\u27s disease-related tau phosphorylation via PAR-1.

Abnormal phosphorylation and toxicity of a microtubule-associated protein tau are involved in the pathogenesis of Alzheimer\u27s disease (AD); however, what pathological conditions trigger tau abnormality in AD is not fully understood. A reduction in the number of mitochondria in the axon has been implicated in AD. In this study, we investigated whether and how loss of axonal mitochondria promotes tau phosphorylation and toxicity in vivo. Using transgenic Drosophila expressing human tau, we found that RNAi-mediated knockdown of milton or Miro, an adaptor protein essential for axonal transport of mitochondria, enhanced human tau-induced neurodegeneration. Tau phosphorylation at an AD-related site Ser262 increased with knockdown of milton or Miro; and partitioning defective-1 (PAR-1), the Drosophila homolog of mammalian microtubule affinity-regulating kinase, mediated this increase of tau phosphorylation. Tau phosphorylation at Ser262 has been reported to promote tau detachment from microtubules, and we found that the levels of microtubule-unbound free tau increased by milton knockdown. Blocking tau phosphorylation at Ser262 site by PAR-1 knockdown or by mutating the Ser262 site to unphosphorylatable alanine suppressed the enhancement of tau-induced neurodegeneration caused by milton knockdown. Furthermore, knockdown of milton or Miro increased the levels of active PAR-1. These results suggest that an increase in tau phosphorylation at Ser262 through PAR-1 contributes to tau-mediated neurodegeneration under a pathological condition in which axonal mitochondria is depleted. Intriguingly, we found that knockdown of milton or Miro alone caused late-onset neurodegeneration in the fly brain, and this neurodegeneration could be suppressed by knockdown of Drosophila tau or PAR-1. Our results suggest that loss of axonal mitochondria may play an important role in tau phosphorylation and toxicity in the pathogenesis of AD