Silicate Microfiber Scaffolds Support the Formation and Expansion of the Cortical Neuronal Layer of Cerebral Organoids With a Sheet-Like Configuration

Terada Eisaku, Bamba Yohei, Takagaki Masatoshi, et al. Silicate Microfiber Scaffolds Support the Formation and Expansion of the Cortical Neuronal Layer of Cerebral Organoids With a Sheet-Like Configuration. Stem Cells Translational Medicine 9, 519 (2023); https://doi.org/10.1093/stcltm/szad066.Cerebral organoids (COs) are derived from human-induced pluripotent stem cells in vitro and mimic the features of the human fetal brain. The development of COs is largely dependent on “self-organization” mechanisms, in which differentiating cells committed to cortical cells autonomously organize into the cerebral cortex-like tissue. However, extrinsic manipulation of their morphology, including size and thickness, remains challenging. In this study, we discovered that silicate microfiber scaffolds could support the formation of cortical neuronal layers and successfully generated cortical neuronal layers, which are 9 times thicker than conventional COs, in 70 days. These cortical neurons in the silicate microfiber layer were differentiated in a fetal brain-like lamination pattern. While these cellular characteristics such as cortical neurons and neural stem/progenitor cells were like those of conventional COs, the cortical neuronal layers were greatly thickened in sheet-like configuration. Moreover, the cortical neurons in the scaffolds showed spontaneous electrical activity. We concluded that silicate microfiber scaffolds support the formation of the cortical neuronal layers of COs without disturbing self-organization-driven corticogenesis. The extrinsic manipulation of the formation of the cortical neuronal layers of COs may be useful for the research of developmental mechanisms or pathogenesis of the human cerebral cortex, particularly for the development of regenerative therapy and bioengineering

A Study of the Effect by Intellectual-Tests under White Noise and Back-Ground-Music

We have two chapters in this study. The details are as follows; Chapter 1. This chapter is the sequel to our treatise reported in the preceding Bulletin of The Faculty of Education Univ. of Tokyo Vol. 15. In that Bulletin, we hypothesized that the effect of noises on psychological performance was not merely inhibitory but also accelerating, designated them as "inhibitory effect" and "accelerating effect". The main purpose of this chapter is to investigate these two effects, in case of performing Intelligence-Tests which has 5 intellectual factors from simplicity to complexity. Experimental conditions and procedures are as follows ; Test : Intelligence-Test, known as Todai A-S form. Noise conditions : Control group-about 40 dB(A), Experimental group-White noise 80 dB(A), produced by Noise Field Generator, placed at the center of the experimental rooms. Grouping: 3 groups. Gl-Control. G2-Experimental, doing the test in Usual Sequence, G3-Experimental, doing the test in Reverse Sequence. Subjects : The first and the second year Junior High School, about 50 members in each group. The main findings of this chapter were shown under. Concerning the complex intellectual factors in intelligence-test, "inhibitory effect" came first which was shown in Reverse Sequence Group : G3. But in the simple intellectual factors, " accelerating effect" had a tendency to come first, which was same as Kroeperin-Test composed of mathematical computation. Anyway two effects mentioned the above had different influence upon intellectual factors by the degree of complexity. Chapter 2. In this chapter, we investigated the effect caused by exposure to the music, by carrying out experimentally on 173 male and 173 femail junior high school pupils engaged in some intellectual performance. The findings of this chapter were as follows ; 1. The intellectual performance in the case of the quiet condition was more efficient in comparison with that of the music exposure, 2, The inefficiency under the music was not related to the degree of the undesirability against music, but related to the degree of the unfamiliarity with music

A Study of the Effect on Intellectual-Tests under White Noise and Back Ground Music(Rep. 2)

We have two chapters in this study. Chapter 1. The main purpose of this chapter is to investigate the effect of Back Ground Music (B. G. M. ) , especially the effect of masking nuisance noises, in case of pupils\u27 performing Intellectual-Tests. And we also investigated the reason why pupils learned their lessons at their homes under the conditions of B.G.M.. The main findings of this chapter is as follows; 1. B.G.M. used to mask nuisance noises softens the suffering given by nuisance noises. 2. In case of performing Intellectual-Tests, the condition under "B. G. M. with nuisance onises" is more efficient than that under "noises only". 3. The main reason of pupils\u27 learning under the conditions of B.G.M. is not that they want to increase the efficiency of their lessons but that they want to listen to music itself. Chapter 2. This chapter is the sequel to our treatise reported in the preceding Bulletin of the Faculty of Education, Univ. of Tokyo, Vol. 16. We investigated whether the effect of music upon intellectual performance varies by each subject\u27s skillfulness or not. We have the following conclusion. "Inhibitory effect" of music was obviously observed in those subjects who had lower skillfulness in performing Intellectual-Tests

An Experimental Study on the Effect of Continuous and Intermittent White Noise upon Uchida-Kraepelin Test

We investigated the effect of white noise, continuous and intermittent, upon Uchida-Krae-pelin Test. Subjects were 230 male and 230 female junior high school students. They took the test under three different conditions, namely, ordinary level of room noise (about 45 dBA), continuous white noise and intermittent one (both; about 70dBA). The main findings of this study were as follows; 1. White noise had inhibitory effect upon the performance of the test, especially in the first period. 2. It seemed that intermittent white noise was more inhibitory than continuous white noise, but the difference was not statistically significant. 3. Inhibitory effect of white noise was clearly observed in those subjects who had the lowest skillfulness in performing the test

Multi-Junction Switching in Bi2_2Sr1.6_{1.6}La0.4_{0.4}CuO6+δ_{6+\delta} Intrinsic Josephson Junctions

We study the dynamics of multi-junction switching (MJS): several intrinsic Josephson junctions (IJJs) in an array switch to the finite voltage state simultaneously. The number of multi-switching junctions ($N$) was successfully tuned by changing the load resistance serially connected to an Bi$_2$Sr$_{1.6}$La$_{0.4}$CuO$_{6+\delta}$ IJJ array. The independence of the escape rates of $N$ in the macroscopic quantum tunneling regime indicates that MJS is a $successive$ switching process rather than a $collective$ process. The origin of MJS is explained by the gradient of a load curve and the relative magnitudes of the switching currents of quasiparticle branches in the current-voltage plane

A Study of the Effect on Intellectual-Tests under White Noise and Back-Ground-Music (Report 3)

We have two chapters in this study, both of which are the sequel to our treatise reported in the preceding Bulletin of the Faculty of Education, University of Tokyo, Vol. 17. Chapter 1. The main findings of this chapter are shown below : 1. B. G. M. of which tempo is rapid, has less effect to soften the suffering given by nuisance noises, in comparison with slow tempo B. G. M.. 2. In the cases of performing Intellectual-Tests, both groups under nuisance noises and, noises with the rapid tempo B. G. M. are more inhibitory than the controled one. Chapter 2. The main purpose of this chapter is to study the effect of B.G. M. upon intellectual performance, especially in case of giving the different tempo music, namely "rapid" or "slow". We have the conclusion as follows : Rapid tempo music has little inhibitory effect in performing intellectual work, consistently. And, slow tempo music has strong inhibitory effect immediately after performing the work