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Oligodendrocyte progenitor cells during postnatal development and upon visual loss in mouse visual cortex
Get PDF創価大学博士（工学）オリゴデンドロサイト前駆細胞は、感覚経験によって細胞の増殖・分化が調整される。視覚剥奪依存的オリゴデンドロサイト前駆細胞の変化は、マウスの一次視覚野においては未だ明らかとされていない。本研究では、眼優位性臨界期の開始頃、即ち生後25日目の時期特異的にオリゴデンドロサイト前駆細胞の増殖能がピークとなり、尚、開眼開始(生後14~15日目)からの両眼球剥奪によって、一次視覚野の大脳皮質下層と皮質下白質において更なる増加が観られた。これらの結果を二つの章に分けて詳細に述べた。
生後25日目の健常マウスでは、細胞周期を通して分裂した娘細胞が対称的に分化へ進んだ。視覚剥奪では、対称的に細胞分裂した未分化性娘細胞が細胞周期のG1期に戻ったため増殖能が増加する一方、G0期に脱して分化へ進む細胞は減少した。これらの未分化性状態の亢進は、ソニックヘッジホッグ(Sonic hedgehog, Shh)シグナル経路の一部を媒介する可能性が挙げられた。その5日後（生後30日目）、未分化性オリゴデンドロサイト前駆細胞の殆んどは分化へ進み、僅かは更に分化が進み成熟細胞となった。視覚剥奪マウスでは、対称性モードの娘細胞が静止状態と分化状態が転換され、未分化性が維持された。やがて生後50日目の健常マウスでは、増殖細胞の殆んどが成熟オリゴデンドロサイトへ分化した。視覚剥奪マウスでは更なる成熟オリゴデンドロサイト数が見られ、それは主に対称的・非対称的に成熟細胞へ分化が増加したためであった。尚、増殖細胞に関わらず、全ての成熟細胞の分布や蛍光強度を検討すると、視覚剥奪によって更に細胞数が増加し、ミエリン形成の更なる増加も示唆された。
皮質下白質においては、第一章の結果のように生後25日目に、時期特異的に細胞の増殖能がピークと増加し、視覚剥奪による更なる増加が示された。この増加は、増殖細胞の対称性・非対称性に関わらず、未分化性を促進させたためであった。視神経切断による視覚剥奪では、視神経の軸索がたどり着く視覚視床において反応性アストロサイトやミクログリア・マクロファージが増加したが、一次視覚野では影響しなかった。即ち、視神経切断による炎症反応は視床でのみ生じ、視覚野の皮質・白質では神経回路の再編成よる未分化性増加が示唆された。増殖細胞はやがて成熟細胞へ分化し、増殖5日後（生後30日目）をピークとして増加し、視覚剥奪マウスでも同様であった。皮質の結果と異なり、視覚剥奪による成熟細胞の促進は影響しなかった。
本研究では、眼優位性臨界期開始頃、オリゴデンドロサイト前駆細胞の発達に重要な時期であると示唆され、やがて視覚剥奪による皮質内と白質で異なる発達・制御をもつ事が明らかとなった。視覚剥奪下、皮質下層では、生後25日目の時期特異的に増殖した細胞の未分化性維持はShhシグナル経路の一部を介して促進され、大脳視覚皮質の下層ではやがて成熟オリゴデンドロサイトへの分化を更に促進させた。白質では、生後25日目にも未分化性細胞が視覚剥奪によって増加する一方、成熟への促進は影響しなかった。従って、視覚剥奪すると神経回路の再編成が生じるが、それに伴う皮質内と白質においてオリゴデンドロサイト前駆細胞の発達時期・制御が異なる事が明かされた。この結果は、やがて神経回路再編成にオリゴデンドロサイトの発達が関与する事を示唆する。doctoral thesi
Studies on the functional role of HVR domain in the small Gprotein H-Ras and its application to Artificial control of Ras
Get PDF創価大学博士（工学）Ras is one of the Small G proteins which is known as a molecular switch, is a central regulator of cellular signal transduction processes leading to transcription, cell cycle progression etc. The active ON state and the inactive OFF state of Ras are regulated by the two factors. GTPase activating protein (GAP) induce hydrolysis of GTP to GDP resulting in formation of inactive state of Ras. On the other hand, Guanine nucleotide exchange factor (GEF) replaces GDP with GTP and make Ras ON state. The switching mechanisms utilizing conformational changes in the nucleotide-binding motifs have been well studied at the molecular level. Interestingly, recent studies have shown that G proteins have a common nucleotide-binding motif with the ATP-driven motors, myosin and kinesin. These nucleotide binding proteins might be evolved from a common nucleotide-binding ancestral protein and share a common catalytic core region including switch I, Switch II and P-loop, and molecular mechanism utilizing a nucleotide hydrolysis cycle . Previously Studies demonstrated that incorporation artificial regulatory nanodevices such as a photochromic molecule into the functional site of Kinesin enable to control ATPase activity photoreversibly . Interestingly, Hyper Variable Region (HVR) is one of the functional parts of the G proteins in which modification induce multimerization and interaction with plasma membrane of Ras. In physiological state Ras forms the nanocluster on the plasma membrane by the lipid modifications of the hypervariable region (HVR) at C-terminal to exhibit physiological function . It is believed that this HVR domain might play a crucial role in Ras protein to its cellular function. First in this study, we have demonstrated that chemical modification of cysteines residues in HVR with caged compounds instead of lipidation induces multimerization of H-Ras. Sulfhydryl-reactive caged compound, 2-Nitrobenzyl bromide (NBB) was stoichiometrically incorporated into the cysteine residue of HVR and induced formation of Ras multimer. Light irradiation induced elimination of 2-Nitrobenzyl group, resulting in conversion of multimer to monomer. SEC-HPLC and Small angle X-ray scattering (SAXS) analysis revealed that the H-Ras forms pentamer. Electron microscopic observation of the multimer showed circular ring shape which is consistent with the structure estimated from X-ray scattering. The shape of the multimer may reflect the physiological structural state of Ras. It was suggested that the multimerization and monomerization of H-Ras was controlled by the modification with caged compound at HVR and light irradiation reversibly. However, caged compound exhibit irreversible photo eliminating reaction. Therefore, caged compounds does not work as a reversible photo-switch. In further study, we employed the azobenzene derivative as a photo reversible nano switching device and incorporated into the HVR to control Ras function. We introduced the two highly different polarity photochromic sulfhydryl-reactive azobenzene derivatives, 4-phenylazophenyl maleimide (PAM) and 4-chloroacetoamido-4’-sulfo-azobenzene (CASAB) into cysteine residues in HVR to regulate the GTPase activity by photoirradiation. PAM was stoichiometrically incorporated into the three cysteine residues in HVR and induced multimerization. The PAM-modified mutants exhibited reversible alterations in GTPase activity accelerated by GEF And GAP, and multimerization accompanied by photoisomerization upon exposure to ultraviolet and visible light irradiation. CASAB was incorporated into two of the three cysteine residues in HVR but not induced multimerization. GTPase of the H-Ras modified with CASAB was photocontrolled more effectively than PAM-H-Ras. Interestingly CASAB modification did not induced H-Ras multimerization. The results suggest that incorporation of photochromic molecules into its functional site enables photoreversible control of the function of the small G protein Ras. Well known photochromic compounds show light sensitivity at a specific wavelength. Upon light irradiation photochromic compounds can change their structure and functions. There are two types of mechanisms observed for returning to their original states. A mechanism that returns by irradiating light with a different wavelength, it’s called P-type such as diarylethene and fulgide. Another one, a mechanism that returns by heat, it’s called T-type such as spiropyran, azobenzene, and stilbenes. In this study we used small caged compound which may mimic the physiological lipidation and photochromic compound such as azobenzene derivatives. We employed a sulfhydryl group reactive caged compound to modify the cysteine residues in HVR. NBB used in this study is one of the well-known cage compounds and can be specifically introduced into the thiol group of the cysteine residue as shown in Then, by light irradiation at 340-400 nm, the nitrobenzyl group is eliminated and the protein reversibly returns to its original state. There are 6 cysteine residues in Human H-Ras. Three of them are in the globular domain and C118 is located on the surface. The remaining three cysteine (C181, C184,C186) which are known as lipidation sites are in the HVR domain. HVR domain is exposed to solvent. NBB is incorporated in to the cysteine residues stoichiometrically. Therefore, it is assumed that the four cysteine residues (C118, C181, C184 and C186) exposed to solvent are modified specifically.doctoral thesi
Piano hiki utai Instructional Methods for Students Aiming to Become Childcare Workers [4]:Study on the Problems and Advantages Faced by Piano Hiki Utai Students in Online Lessons: Based on Students’ Perceptions Gained from a Questionnaire Survey
Get PDFThe purpose of this study was to clarify the problems and advantages faced by students of Piano Hiki Utai (i.e., the practice of singing while playing piano) during online lessons, and to examine how to teach Hiki Utai (i.e., singing while playing) to students in the future.
The problems most identified by students in the questionnaire were broadly classified into four categories: 1) problems arising from the unstable communication environment; 2) problems caused by the learning environment, such as a lack of musical instruments for the students and/or feelings of loneliness; 3) problems related to noise caused by family members and other elements pertaining to the home surroundings; and 4) problems caused by the economic burden of having to purchase a personal keyboard.
As for the advantages and methods employed by students, it was found that students were able to 1) increase and secure their practice times; 2) see changes in their practice contents, such as practicing to specifically control the strength of their sounds and/or enrich their musical expressions; 3) take lessons in a relaxed manner while having their privacy protected; and 4) it was also found that students’ attitudes toward lessons became more positive overall.
Before conducting the survey, we expected to only expose the disadvantages of online lessons; however, as we conducted the study, we found that there were certain advantages that were only present in the online learning environment. We therefore deemed it best to include such data, so as to highlight a teaching method that could potentially further build on these advantages.
While it is necessary to provide guidance aimed at technical improvement when thinking about teaching for Hiki Utai, this study’s results suggest that, at the same time, it is necessary to also provide guidance that creates interaction. Such an approach to teaching could include cases where the instructor cares for students and motivates them to practice, and/or provides guidance that deepens students’ understanding of the significance of performing Hiki Utai.
In the future, we would like this study’s results to lead to the establishment of a lesson style and teaching method for Piano Hiki Utai that includes not only online lessons but faceto-face ones as well.departmental bulletin pape
The academic history and career development process of a person with intellectual disability（ 2）: What a graduate of the special support school for intellectual disabilities learned during his industrial internship in high school
Get PDFThe purpose of this study is to contribute to the improvement and enhancement of vocational education and career development support by analyzing the academic history and career development process of a high school graduate of the special support school for intellectual disabilities through conducting qualitative interviews.
The interview data were reinvestigated and reinterpreted for this paper in particular, in which the researcher overviewed materials available for the informant's academic and career counseling in his highschool days, followed by elucidating the dynamics of his learning process.
As a result, the researcher has found dense description from interview sricpts in the materials, which leads to discussing the practical implications regarding the primary objectives of using such resources effectively in the process of the acceptance/acquisition of one's disabilities and vocational readiness as well as a vision of what teachers should learn and be able to do in order to accomplish the objectives.departmental bulletin pape
Challenges for new learning courses in elementary schools for special needs schools ― From a questionnaire survey to the board of education staff ―
Get PDFAt the elementary school of the special needs school, the curriculum based on the new curriculum guidelines announced in 2017 was implemented in 2020. In this study, we investigated the opinions of the Board of Education regarding the subjects of the revised School for Special Needs for Intellectual Disabilities, individual education plans, continuity of learning, and the handling of curriculums for children with multiple disabilities.
As a result, we found the following:
Significant improvements in the subject matter of people with intellectual disabilities in the new learning course indicate that teaching content may be improved. Each school has a variety of issues regarding how to devise ways to link the assessment and improvement of individual education plans to curriculum assessment and improvement.departmental bulletin pape
