“in vivo two-photon functional Ca2+ imaging” is a powerful tool to analyze neural circuits of the cerebral cortex in the physiological condition. To monitor activities of excitatory neurons, inhibitory (GABAergic) neurons and astrocytes, we applied this imaging method to visual cortex of transgenic mice, in which GABAergic neurons express fluorescent protein (EGFP or Venus). With this method, we can monitor the neural activities from hundreds of excitatory and GABAergic neurons (and also from astrocytes) in vivo. We found that the difference in response selectivity and ocular dominance plasticity between excitatory and GABAergic neuron in the mouse visual cortex.
Unlike other molecular motors, myosin VI has much larger and broadly distributed step sizes than those predicted from its structure. Here, this discrepancy was consistently elucidated by highly sensitive single molecule imaging technique. The large step sizes and its variability were attributed to an extended rigid lever arm and two distinct tilt angles which causes newly found large and small step size.
We review the relationship between information and thermodynamics, especially with focusing on the issues surrounding the Maxwell’s demon. Furthermore, we briefly introduce our experimental demonstration of an “information-heat engine”, which can pump heat from an isothermal environment by using information about the system’s microscopic degrees of freedom.
Photosystem II (PSII) is a membrane-protein complex consisting of 17 trans-membrane subunits and 3 peripheral, extrinsic subunits with a total molecular mass of 350 kDa for a monomer. PSII performs a series of light-induced electron transfer reactions, leading to the conversion of light energy into biologically useful chemical energy, coupled with this is the splitting of water and generation of molecular oxygen. Both the chemical energy converted and molecular oxygen generated by PSII are indispensible for sustaining life on the earth; thus PSII is an extremely important protein complex. We have succeeded in crystallizing the PSII complex at a resolution of 1.9 Å, and analyzed its structure. Here we describe the structure of PSII, in particular the Mn4CaO5-cluster, which is the catalytic center of water-splitting, analyzed at the atomic resolution. Based on these, we discuss the possible mechanisms of light-induced water-splitting and its implications in artificial photosynthesis.