The purpose of this study was to quantify the clearance of amyloid-β (Aβ) protein by auditory stimulation in a mouse model of Alzheimer's disease (AD). Accumulation of Aβ is thought to be one of the causes of AD. It has been confirmed that Aβ in 5XFAD mice, a mouse model of AD, is reduced by auditory stimulation at a period of 40 Hz, in which sounds are switched on and off 40 times per second. A previous study showed that auditory stimulation of 1-8 msec duration may be particularly effective for Aβ clearance. However, quantitative evaluation of Aβ has not yet been conducted. Therefore, in this study, we quantitatively evaluated the effect of auditory stimulation on Aβ clearance by analyzing the amount of Aβ. As a result, auditory stimulation using a sound with a period of 40 Hz, a pitch of 10 kHz, and a duration of 3 msec reduced the magnitude of Aβ.

PTEN, a tumor suppressor that is frequently mutated in a wide spectrum of cancers, exerts PI(3,4,5)P3 phosphatase activities that are regulated by its dynamic shuttling between the membrane and cytoplasm. Direct observation of PTEN in the interfacial environment can offer quantitative information about the shuttling dynamics, but remains elusive. Here we show that positively charged residues located in the cα2 helix of the C2 domain are necessary for the membrane localization of PTEN via stable electrostatic interactions in Dictyostelium discoideum. Single-molecule imaging analyses revealed that PTEN molecules moved distances much larger than expected had they been caused by lateral diffusion, a phenomenon we call "hopping." Our novel single-particle tracking analysis method found that the cα2 helix aids in regulating the hopping and stable-binding states. The dynamically established membrane localization of PTEN was revealed to be essential for developmental processes and clarified a fundamental regulation mechanism of the protein quantity and activity on the plasma membrane.

We have developed two technologies for 3D magnetic microstructures, with a wide size range between 5μm to 2mm. The first technology enables us to obtain density controlled 3D magnetic microstructures. The size of this structure is approximately 500μm. In this scale, controlling density is vital for magnetic micro actuators, because the effect of gravity is strong. To adjust density, we developed the world's first “density controllable magnetically photocurable (DMPC) polymer.” The DMPC polymer is a mixture of hollow microcapsules (density, 0.03 g/cm3), magnetic particles, and photocurable polymer. We can obtain desired relative density between 0.5 to 1.7 by adjusting the concentration of microcapsules. In addition, we succeeded in 3D velocity control of a screw-type magnetic micro actuator with neutral buoyancy in water. The delay time was 32msec, which is smaller than video rate. In addition, the actuator possessed 6 degrees of freedom. The second technology realized a 5μm magnetic micro actuator, which is a combination of a 3D transparent structure and 2D magnetic structure. Various photocurable polymers can be applied as the 2D structure in this process, although we used magnetically photocurable polymer in this report. Furthermore, we have succeeded in driving a ferromagnetic micro actuator, whose diameter is as small as 1μm. These two fabrication processes will become key technologies in both the medical field and the field of life sciences, because they can supply a wide variety of 3D micro structures with small effort.