Scale Space Calibrates Present and Subsequent Spatial Learning in Barnes Maze in Mice.

Animals are capable of representing different scale spaces from smaller to larger ones. However, most laboratory animals live their life in a narrow range of scale spaces like homecages and experimental setups, making it hard to extrapolate the spatial representation and learning process in large scale spaces from those in conventional scale spaces. Here, we developed a 3-m diameter Barnes maze (BM3), then explored whether spatial learning in the Barnes maze (BM) is calibrated by scale spaces.

One-chip sensing device (biomedical photonic LSI) enabled to assess hippocampal steep and gradual up-regulated proteolytic activities.

We developed an implantable one-chip biofluoroimaging device (termed biomedical photonic LSI; BpLSI) which enabled real-time molecular imaging with conventional electrophysiology in vivo in deep brain areas. The multimodal LSI enabled long-term sequential imaging of the fluorescence emitted by proteolysis-linked fluorogenic substrate. Using the BpLSI, we observed a process of stimulation-dependent modulation at synapse with multi-site (16 x 19 pixel) in widespread area and a high-speed video rate, and found that the gradual up-regulated proteolytic activity in a wide range of hippocampal CA1 area and the steep activity in local area, indicating that the proteolysis system is a basis for the fixation of long-term potentiation in post-excited synapses in the hippocampus.

A new neural imaging approach using a CMOS imaging device.

We have developed and demonstrated the use of a dedicated CMOS device for in vivo functional imaging of the mouse brain. In order to achieve this, a 176 x 144 pixel array image sensor is designed, fabricated and specially packaged using a novel process. By using on-chip fluorescence imaging configuration, we have successfully imaged deep inside the hippocampus of the mouse brain.