As a mission to be the inter-university research institute, NIPS conducts joint studies with researchers from domestic or foreign universities and other research institutes. NIPS provides specialized equipment, large-scale equipment, and research facilities, and develops new equipment for morphological and functional 4D imagingｓ of various organs such as the brain.
Hitachi H-1250M is the unique high voltage electron microscope specially designed for biological and medical sciences. The microscope usually operates at an accelerating voltage of 1,000 kV. The column pressure is kept at less than 7 × 10 -6 Pa near the specimen position. The image acquisition is performed at the magnification ranges from 1k to 1,000 k. Projections of thick biological specimens up to 5 μm are collected at tilt angles between ±60° using the side-entry specimen holder, which gives 3-dimentional ultra-structures of biological specimens at nanometer scales.
MRI is an imaging technique that utilizes the nuclear magnetic resonance of the hydrogen atom. Not only to image the anatomical details of the brain, but MRI also allows exploring the neural substrates of human cognitive function by the visualization of the task-related changes in regional cerebral blood flow （functional MRI）. For over a decade, we have been working on 3T MRI to investigate higher brain function of a human. To simultaneously measure the neural activities of two participants during their social interaction, we have recently installed dual functional MRI system with two 3T MRI. Furthermore, ultra-high field (7T) MRI system has been installed. In 2016 and 2017, cooperative study projects using 7T machine were performed for the purpose of technical assessment and development. After confirming stable operation, it will be fully provided for cooperative studies.
Magnetoencephalography （MEG） has a potential to measure brain activities with better temporal and spatial resolution in milliseconds and millimeter, respectively, compared with other methods such as functional magnetic resonance imaging. Event-related magnetic fields following various kinds of sensory stimulation are mainly analyzed. Also, background brain activities （brain waves） in various conditions can be analyzed.
Phase contrast electron cryomicroscopy is an electron microscope developed for observing close-to-life state biological samples with a combination of rapid freezing and ice embedding sample preparation methods. Biological specimens up to 200 nm thicknesses can be observed with high-resolution and high-contrast. Ultrastructure analyses of protein molecules, viruses, bacteria, cultured cells and frozen tissue sections are performed with this novel microscopic system.
Serial block-face scanning electron microscope（SBF-SEM） is an advanced 3-D nano-imaging equipment. Two different types of SBF-SEM are available; high-resolution and wide-area types. Resin-embedded biological specimens are trimmed by a diamond knife equipped inside the chamber, and the block-face images are acquired by scanning electron microscopy （SEM）. 3-D structures of the specimens are finally reconstructed from the acquired serial block-face images. 3-D structures of large biological specimens like a brain tissue can be visualized at the nanometer resolution.
Multi-photon excitation is a method to visualize living tissue by exciting the fluorescence molecules with the tightly focused near-infrared femtosecond pulse laser. Since the longer wavelength is used for multi-photon excitation, it had a superior deeper tissue penetration and reduced phototoxicity than those of single-photon excitation. Our 2-photon microscopes have a top level specification for deep tissue imaging and can be applied to the imaging of neurons and glial cells in deep tissues such as mouse brain. Recently, we also developed a 2-photon fluorescence imaging microscope which can be applied to image protein-protein interaction and the protein activity.
We analyze the following physiological parameters in mice and rats:
1） Single unit recording from motor-related brain regions in awake state,
2）Neurotransmitter release in local brain regions in free moving animals, 3） Regional neural activity detected as intrinsic signals with taking the advantage of light fluorescent dynamics of flavin or hemoglobin, 4） Energy intake and expenditure in free-moving animals,
5） Body temperature, heart rate and blood pressure in free-moving animals,
6） Measurement of cardiac functions using Langendorff-perfused hearts and non-invasive measurement of cardiac functions and peripheral blood flow using anesthetized mice.
The National Institute for Physiological Sciences（NIPS）...