Toshihiko Noda

CMOS image sensor integrated with micro-LED and multielectrode arrays for the patterned photostimulation and multichannel recording of neuronal tissue.

We developed a complementary metal oxide semiconductor (CMOS) integrated device for optogenetic applications. This device can interface via neuronal tissue with three functional modalities: imaging, optical stimulation and electrical recording. The CMOS image sensor was fabricated on 0.35 μm standard CMOS process with built-in control circuits for an on-chip blue light-emitting diode (LED) array. The effective imaging area was 2.0 × 1.8 mm². The pixel array was composed of 7.5 × 7.5 μm² 3-transistor active pixel sensors (APSs). The LED array had 10 × 8 micro-LEDs measuring 192 × 225 μm². We integrated the device with a commercial multichannel recording system to make electrical recordings.

Wireless intra-brain communication for image transmission through mouse brain

We demonstrate wireless image data transmission through a mouse brain. The transmission characteristics of mouse brain is measured. By inserting electrodes into the brain, the transmission efficiency is drastically increased. An AM signal modulated with the image data from an implantable image sensor was launched into the brain and the received signal was demodulated. The data was successfully transmitted through the brain and the image was reproduced.

CMOS On-Chip Optoelectronic Neural Interface Device with Integrated Light Source for Optogenetics

A novel optoelectronic neural interface device is proposed for target applications in optogenetics for neural science. The device consists of a light emitting diode (LED) array implemented on a CMOS image sensor for on-chip local light stimulation. In this study, we designed a suitable CMOS image sensor equipped with on-chip electrodes to drive the LEDs, and developed a device structure and packaging process for LED integration. The prototype device produced an illumination intensity of approximately 1 mW with a driving current of 2.0 mA, which is expected to be sufficient to activate channelrhodopsin (ChR2). We also demonstrated the functions of light stimulation and on-chip imaging using a brain slice from a mouse as a target sample.

Light-controlled retinal stimulation on rabbit using CMOS-based flexible multi-chip stimulator

We implemented a light-sensing function on CMOS-based multi-chip stimulator for retinal prosthesis. Using the light-sensing circuitry attached to each stimulation electrode, the flexible multi-chip stimulator is capable of image-based patterned stimulation. We verified the function of the light-controlled decision based on the light intensity measured just beside the stimulation site. We also experimentally demonstrated in vivo retinal stimulation on rabbits retina with light-controlled decision. The result of the present work is a simplified demonstration for the concept of retinal prosthesis with on-site imaging.

CMOS-based optical energy harvesting circuit for biomedical and Internet of Things devices

In this work, we present a novel CMOS-based optical energy harvesting technology for implantable and Internet of Things (IoT) devices. In the proposed system, a CMOS energy-harvesting circuit accumulates a small amount of photoelectrically converted energy in an external capacitor, and intermittently supplies this power to a target device. Two optical energy-harvesting circuit types were implemented and evaluated. Furthermore, we developed a photoelectrically powered optical identification (ID) circuit that is suitable for IoT technology applications.

Micro CMOS image sensor for multi-area imaging

We propose a micro complementary-metal-oxide semiconductor (CMOS) image sensor for simultaneous multi-area imaging. The sensor is designed for observation of mouse brain and its dimension is 550 µm × 850 µm. By connecting the sensors one after another, all the sensors are operated with only 5 lines. We demonstrate multi area imaging with a two sensor system as a preliminary experiment.

A CMOS-based multichip flexible retinal stimulator for simultaneous multi-site stimulation

We developed a novel CMOS-based multichip flexible neural stimulator with on-chip stimulation generator. It enables simultaneous multi-site stimulation. We also propose a new type of multi-chip retinal stimulator with single electrode / unit chip configuration. We successfully performed simultaneous multi-site stimulation in an in vivo retinal stimulation experiment using a rabbit.

Investigation of detectability of a biomedical photonic LSI (BpLSI) device for voltage-sensitive dye imaging of mouse visual cortex

s / Neuroscience Research 71S (2011) e108–e415 e205 Research fund: Global COE Program Center of Human-Friendly Robotics Based on Cognitive Neuroscience of the Ministry of Education, Culture, Sports, Science and Technology, Japan. doi:10.1016/j.neures.2011.07.885 P2-u09 Density-dependent changes of the stoichiometry of KCNQ1–KCNE1 ion channel complex revealed by direct subunit counting using single molecule imaging Koichi Nakajo 1,2,3 , Maximilian H. Ulbrich 3,4, Yoshihiro Kubo 1,2, Ehud Y. Isacoff 3,5 1 Div. of Biophys. & Neurobiol., NIPS, Okazaki, Japan 2 Dept. of Physiol. Sci., SOKENDAI, Hayama, Japan 3 Dept. of Mol. & Cell Biol., UC Berkeley, USA 4 BIOSS, Albert-Ludwigs-Univ., Freiburg, Germany 5 Phys. Biosci. Div., LBNL, Berkeley, USA KCNQ channel is a Shaker-type voltage gated potassium channel subunit. Five KCNQ genes (KCNQ1–5) have been identified in the human genome and most of them are related to inherited human diseases such as cardiac arrhythmia, epilepsy and deafness. Like other potassium channels, four KCNQ subunits are thought to form one ion channel (tetramer). In addition, KCNQ1 forms ion channel complex with single transmembrane KCNE proteins, which dramatically change KCNQ1 channel properties such as current amplitude, gating kinetics and voltage dependence. To determine how many KCNE proteins are included in a single KCNQ1 channel complex, we applied the subunit counting method using single-molecule imaging technique under a total internal reflection microscope (Ulbrich, 2007). By directly detecting bleaching events from each single fluorescent protein (FP), the number of FP-tagged subunits in a single protein complex can be determined. We tagged KCNE1 and KCNQ1 with green and red fluorescent proteins (GFP and mCherry) respectively and counted the number of GFP (KCNE1) colocalized with mCherry (KCNQ1) signal. We observed up to four bleaching events from a single fluorescent spot, indicating that four KCNE1 subunits can bind to KCNQ1 tetramer. Interestingly, the stoichiometry was not fixed but rather flexible; the number of KCNE proteins in one KCNQ1 channel was between 0 and 4. Relative expression densities of KCNQ1 and KCNE1 were shown to be critical for the stoichiometry; higher KCNE1 protein expression increased the fraction of KCNQ1 channels with 4 KCNE1 subunits. Relative surface expression levels of KCNQ1 channels and KCNE subunits may thus play an important role in determining the firing property of excitable cells. Research fund: KAKENHI 22790223. doi:10.1016/j.neures.2011.07.886 P2-u10 Investigation of detectability of a biomedical photonic LSI (BpLSI) device for voltage-sensitive dye imaging of mouse visual cortex Takuma Kobayashi 1,3 , Mayumi Motoyama 1, Sawadsaringkam Yosmongkol 1, Ayato Tagawa 1, Toshihiko Noda 1,3, Kiyotaka Sasagawa 1,3, Takashi Tokuda 1,3, Hideki Tamura 2,3, Yasuyuki Ishikawa 2,3, Sadao Shiosaka 2,3, Jun Ohta 1,3 1 Photonic Device Sci. Lab., Grad. Sch. of Materials Sci., NAIST, Ikoma, Japan 2 Structural Cell Biol. Lab., Grad. Sch. of Biological Sci., NAIST, Ikoma, Japan 3 CREST, JST, Kawaguchi, Japan To clarify the functional neural networks which regulate the animal behavior organized and represented, it is necessary to measure the real-time multineural activity in living animals. We have been developing an optical imaging technique using the implantable biomedical photonic LSI device which has red absorptive light filter for voltage-sensitive dye imaging (BpLSI-red). The BpLSI-red was developed for sensing fluorescence by the on-chip LSI which was designed by using complementary metal-oxide semiconductor (CMOS) technology, and includes 120 × 268 pixels and its dimensions are 1.0 mm x 3.0 mm. Micro-electro-mechanical systems (MEMS) microfabrication technique was used to post-process the CMOS sensor chip; integration of light emitting diodes (LEDs) for illumination and formation to be suitable for longsequential imaging. Recently, we have succeeded to operate the BpLSI device to measure at more than 60 fps by tuning the digital flow of acquisition information. The measurement condition of the sensor has been improved through trial and error of the fabrication process of color filter, the analysis of fluorescent particles which were implanted in various depth of cortical layer, and the application of electrical stimuli to visual cortex. Additionally, because this implantable BpLSI device is a thin and small structure, it is easy to obtain the image of wide area at the same time by using several sensors with the same brain. For instance, the operation of two devices enabled the visualization of the broad scope of right and left visual cortex. This suggests that our improved measurement application system can simultaneously detect multiple neural activities on various parts of the individual brain. Therefore, this methodology is useful to analyze the dynamic neural network of animals. Research fund: KAKENHI (22800044). doi:10.1016/j.neures.2011.07.887 P2-u11 Bioluminescence imaging of Arc expression in KAinduced seizure Hironori Izumi 1,2 , Tetsuya Ishimoto 3, Miki Shoji 2, Hisashi Mori 3 1 Dept. Neurosci., Grad. Sch. Innovative Life Sci., Univ. Toyama, Toyama, Japan 2 Div. Radioisotope & Radiation Res., Life Sci. Res. Cntr., Univ. Toyama, Toyama, Japan 3 Dept. Mol. Neurosci., Grad. Sch. Med. & Pharm. Sci., Univ. Toyama, Toyama, Japan Induction of the activity-regulated cytoskeleton-associated protein gene (Arc), one of the immediate early genes, in the brain correlates with various sensory processes, natural behaviors, and pathological conditions. In vivo monitoring of Arc expression is useful for the analysis of physiological and pathological conditions in the brain. Therefore, we generated BAC transgenic (Tg) mice of luciferase reporter gene driven by Arc promoter (Arc-Luc) and noninvasively detected the visual-input-dependent changes in bioluminescence in the brain. Here, we examined kainic acid (KA) -induced epileptic seizures in the Arc-Luc Tg mice. KA treatments induced a drastic change in luciferase activity 3 h after the treatment. Furthermore, brain slice imaging and immunohistochemical analysis suggested the detection of bioluminescence signals not only from the cerebral cortex but also from deep brain regions such as the hippocampus after seizure in vivo. These results suggest that induction of Arc-Luc occurs during epileptic seizure and our novel Arc-Luc Tg mice may contribute to the analysis of pathogenesis of chronic seizures in the brain and development of anti-epileptic drugs. Research fund: Food Safety Commission, Japan (No. 1001). doi:10.1016/j.neures.2011.07.888 P2-u12 A background correction method for Raman spectra of mixed neurotransmitters: Toward a new label-free imaging technology of brain activity Naoya Saijo 1 , Jun-ichi Shikata 2, Toru Ishizuka 3, Yuji Uezawa 4, Maki Suemitsu 4, Hajime Mushiake 1,5, Kazuhiro Sakamoto 4 1 Dept. of Physiol., Sch. of Med., Tohoku Univ., Sendai, Japan 2 Dept. of Electrical and Electronics Engineering, College of Engineering, Nihon Univ., Koriyama, Japan 3 Dept. of Developmental Biol. and Neurosci., Grad. Sch. of Life Sci., Tohoku Univ., Sendai, Japan 4 Research Institute of Electrical Communication, Tohoku Univ., Sendai, Japan 5 CREST, Tokyo, Japan Rapid progress in fluorescence imaging over the last two decades has enabled the observation of various biological substances, though inevitably, it involves fluorescent labeling by genetic modification or the administration of fluorescent markers. On the other hand, recent developments in nonlinear optics, such as advanced Raman spectroscopic techniques, have the potential for label-free imaging of spatiotemporal patterns of a wide variety of biological molecules, including neurotransmitters. Real biological samples contain various molecules, and the signals for a molecule within spectra deteriorate not only with noise, but also because of the influence of other molecules and mediums. Thus, before discriminating each target molecule from mixed spectra, an appropriate background correction method is indispensable. Here, we present a new background correction method for Raman spectra, and compare it with other methods using Raman spectra of mixed solutions of neurotransmitters. Research fund: KAKENHI (22120504). doi:10.1016/j.neures.2011.07.889 P2-u13 Fluorescent voltage imaging for detection of networks in Aplysia central nervous system responding to electrical stimulation Hiroto Arawaka , Naoko Matsumoto, Kazuto Aoki, Yasuo Yoshimi Dept Appl Chem, Shibaura Inst of Technol, Tokyo A voltage imaging visualizes signals transmitting among neurons stained by voltage-sensitive dye. The technique is a potential tool for analysis of network in central nervous system (CNS). The voltage imaging of Aplysia CNS would contribute to basic studies of learning and memory taking advantage of its identifiable neurons in CNS. However, the methodology of voltage

Real-time in vivo molecular quantification for freely-moving mouse's hippocampus

P3-f20 Voxel-based morphometry of the relationships between Intelligence Quotient and brain gray matter volume in 156 healthy Japanese children Michiko Asano1, Yasuyuki Taki1, Hiroshi Hashizume1, Yuko Sassa1, Hikaru Takeuchi1, Kohei Asano1, Mijin Lee1, Ryuta Kawashima1,2 1 Division of Developmental Cognitive Neuroscience, IDAC, Tohoku University, Japan; 2 Department of Functional Brain Imaging, IDAC, Tohoku University, Japan