Differential Proliferation Rhythm of Neural Progenitor and Oligodendrocyte Precursor Cells in the Young Adult Hippocampus

Oligodendrocyte precursor cells (OPCs) are a unique type of glial cells that function as oligodendrocyte progenitors while constantly proliferating in the normal condition from rodents to humans. However, the functional roles they play in the adult brain are largely unknown. In this study, we focus on the manner of OPC proliferation in the hippocampus of the young adult mice. Here we report that there are oscillatory dynamics in OPC proliferation that differ from neurogenesis in the subgranular zone (SGZ); the former showed S-phase and M-phase peaks in the resting and active periods, respectively, while the latter only exhibited M-phase peak in the active period. There is coincidence between different modes of proliferation and expression of cyclin proteins that are crucial for cell cycle; cyclin D1 is expressed in OPCs, while cyclin D2 is observed in neural stem cells. Similar to neurogenesis, the proliferation of hippocampal OPCs was enhanced by voluntary exercise that leads to an increase in neuronal activity in the hippocampus. These data suggest an intriguing control of OPC proliferation in the hippocampus

2.Sediments

小樽商科大学Geological Survey of Hokkaido北海道大学Editor : Tazaki, Kazue, Cover:Scanning electoron microscopic photograph of Gallionella sp. in biomats of Aso caldera, Kyusyu, Japan. Various shapes of Gallonella sp. are shown (image:Moriichi, Shingo).COE, 金沢大学 水・土壌環境領域シンポジウム「地球環境における微生物の役割」, 日時：2002年12月4日（水）13：00～, 場所：金沢大学理学部3階第一実験

Microwave Spectrum of the Ethylmethyl Ether Molecule

We have observed rotational transitions of ethylmethyl ether (CH3CH2OCH3) in the 24-110 GHz frequency range. We newly assigned the transitions of four Q-branch series for J=1-38 with Ka=0-5 and six R-branch series of b-type transitions for J=7-37 with Ka=0-3. All these assigned transitions were observed to be split into two or four components due to the internal rotations of the methyl groups. We analyzed the averaged frequencies of the split components on the basis of the Watson A-reduced Hamiltonian, neglecting the effect of the internal rotations. A total of 122 transitions were fitted to eight molecular parameters to a 1s standard deviation of 24 kHz. The parameters A, B, C and DJ were improved, and DJK, Dk, dJ and dK were determined for the first time

Chemo-Enzymatic Synthesis of 1’-Photoreactive Sucrose Derivatives via Ether Linkage

As the 1’-hydroxyl group of sucrose is well known to be less reactive than other primary alcohols, there are no reports on the substitution of a phenoxy group at this position. Chemo-enzymatic synthesis of photoreactive 1’-phenoxy-substituted sucrose was examined to elucidate the functional analysis of sweet receptors

Lzts1 controls both neuronal delamination and outer radial glial-like cell generation during mammalian cerebral development

発生期の大脳で分化細胞と未分化細胞の移動開始をもたらす共通の分子を解明 --「大脳のシワ」形成に貢献する外側放射状グリアはどのように誕生するか--. 京都大学プレスリリース. 2019-07-08.In the developing central nervous system, cell departure from the apical surface is the initial and fundamental step to form the 3D, organized architecture. Both delamination of differentiating cells and repositioning of progenitors to generate outer radial glial cells (oRGs) contribute to mammalian neocortical expansion; however, a comprehensive understanding of their mechanisms is lacking. Here, we demonstrate that Lzts1, a molecule associated with microtubule components, promotes both cell departure events. In neuronally committed cells, Lzts1 functions in apical delamination by altering apical junctional organization. In apical RGs (aRGs), Lzts1 expression is variable, depending on Hes1 expression levels. According to its differential levels, Lzts1 induces diverse RG behaviors: planar division, oblique divisions of aRGs that generate oRGs, and their mitotic somal translocation. Loss-of-function of lzts1 impairs all these cell departure processes. Thus, Lzts1 functions as a master modulator of cellular dynamics, contributing to increasing complexity of the cerebral architecture during evolution