Biology subjects

Ito, D.

Publications and source records attributed to Ito, D..

2 recordsLinked to original sources

bioRxiv2018

Electric field dependent effects of motor cortical TDCS

Transcranial direct current stimulation (TDCS) can modulate motor cortical excitability. However, its after-effects are highly variable between individuals. Individual cranial and brain anatomy may contribute to this variability by producing varying electric fields in each subjects brain. Here we show that these fields are related to excitability changes following anodal TDCS of the primary motor cortex (M1). We found in two experiments (N=28 and N=9) that the after-effects of TDCS were proportional to the individual electric field in M1, calculated using MRI-based models. Individuals with the lowest and highest local electric fields in M1 tended to produce opposite changes in excitability. Furthermore, the effect was field-direction dependent and non-linear with stimulation duration or other experimental parameters. The electric field component pointing into the brain was negatively proportional to the excitability changes following 1 mA 20 min TDCS of right M1 (N=28); the effect was opposite after 1 mA 10 min TDCS of left M1 (N=9). Our results demonstrate that a large part of variability in the after-effects of motor cortical TDCS is due to inter-individual differences in the electric fields. We anticipate that individualized electric field dosimetry could be used to control the neuroplastic effects of TDCS, which is increasingly being explored as a treatment for various neuropsychiatric diseases.

neuroscience↗

bioRxiv2018

An ancestral role of pericentrin in centriole formation through SAS-6 recruitment

The centrosome is composed of two centrioles surrounded by a microtubule-nucleating pericentriolar matrix (PCM). Centrioles regulate matrix assembly. Here we ask whether the matrix also regulates centriole assembly. To define the interaction between the matrix and individual centriole components, we take advantage of a heterologous expression system using fission yeast. Importantly, its centrosome, the spindle pole body (SPB), has matrix but no centrioles. Surprisingly, we observed that the SPB can recruit several animal centriole components. Pcp1/pericentrin, a conserved matrix component that is often upregulated in cancer, recruits a critical centriole constituent, SAS-6. We further show that this novel interaction is conserved and important for centriole biogenesis and elongation in animals. We speculate that the Pcp1/pericentrin-SAS-6 interaction surface was conserved for one billion years of evolution after centriole loss in yeasts, due to its conserved binding to calmodulin. This study reveals an ancestral relationship between pericentrin and the centriole, where both regulate each other assembly, ensuring mutual localisation.\n\nShort summaryThe pericentriolar matrix (PCM) is not only important for microtubule-nucleation but also can regulate centriole biogenesis. Ito et al. reveal an ancestral interaction between the centriole protein SAS-6 and the PCM component pericentrin, which regulates centriole biogenesis and elongation.

cell biology↗