Hirohito Sawahata

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Electrocorticography (ECoG), multichannel brain-surface recording and stimulation with probe electrode arrays, has become a potent methodology not only for clinical neurosurgery but also for basic neuroscience using animal models. The highly evolved primate's brain has deep cerebral sulci, and both gyral and intrasulcal cortical regions have been implicated(More)
Electrocorticogram (ECoG) is a well-balanced methodology for stably mapping brain surface local field potentials (LFPs) over a wide cortical region with high signal fidelity and minimal invasiveness to the brain tissue. To directly compare surface ECoG signals with intracortical neuronal activity immediately underneath, we fabricated a flexible multichannel(More)
Stance instability is seen in late stage Parkinson's disease (PD). Stabilometer-based center-of-pressure (COP) evaluation is an easy, routine method for measuring postural control ability. Most of the stabilometer- and force plate-based studies on upright postural control have discussed horizontal COP component control. Previous studies on vertical(More)
In order to realize a low-invasive and high accuracy Brain-Machine Interface (BMI) system for clinical applications, a super multi-channel recording system was developed in which 4096 channels of Electrocorticogram (ECoG) signal can be amplified and transmitted to outside the body by using an Ultra Wide Band (UWB) wireless system. Also, a high density,(More)
Highly localized neuronal spikes in primate temporal cortex can encode associative memory; however, whether memory formation involves area-wide reorganization of ensemble activity, which often accompanies rhythmicity, or just local microcircuit-level plasticity, remains elusive. Using high-density electrocorticography, we capture local-field potentials(More)
Intracellular recording nanoscale electrode devices provide the advantages of a high spatial resolution and high sensitivity. However, the length of nanowire/nanotube-based nanoelectrodes is currently limited to <10 μm long due to fabrication issues for high-aspect-ratio nanoelectrodes. The concept reported here can address the technological limitations by(More)
Microscale needle technology is important in electrophysiological studies, drug/chemical delivery systems, optogenetic applications, and so on. In this study, dissolvable needle-base scaffold realizes penetration of high-aspect-ratio flexible microneedles (e.g., <5 μm diameter and >500 μm length) into biological tissues. This methodology, which is(More)
Time-frequency analysis of ECoG in V1 1 SUMMARY The primary visual cortex (V1) of the rat consists of a monocular (contralateral-eye-dominant) region (V1M) and a binocular region (V1B) that receives anatomical and functional inputs converging from both eyes. However, V1B contains a heterogeneous mosaic of neurons stochastically discharging with various(More)
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