Publications (2)1.98 Total impact
Article: One-chip sensing device (biomedical photonic LSI) enabled to assess hippocampal steep and gradual up-regulated proteolytic activities.[show abstract] [hide abstract]
ABSTRACT: 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. Mathematical data analysis confirmed the direct involvement of functional proteolysis for neural plasticity.Journal of Neuroscience Methods 07/2008; 173(1):114-20. · 1.98 Impact Factor
Article: An implantable and fully integrated complementary metal–oxide semiconductor device for in vivo neural imaging and electrical interfacing with the mouse hippocampus[show abstract] [hide abstract]
ABSTRACT: We present a technique for in vivo imaging and electrical interface deep inside the mouse brain using a single complementary metal–oxide semiconductor (CMOS) sensor. In this work, we have developed a device which incorporates an imaging array, electrodes, illumination light source and chemical delivery needle. The device encompasses the functionalities for fluorescence imaging and electrophysiological experiments simultaneously. Micro-electro-mechanical systems (MEMS) microfabrication technique is used to post-process the CMOS sensor chip. Integration of light emitting diodes (LEDs) for illumination and formation of on-chip platinum electrodes for electrical interface with neurons complete the packaged device. Using the device, we performed fluorescence imaging and electrophysiological experiments inside the mouse brain. We have successfully induced synaptic response when the Schaffer-collateral pathway of the mouse hippocampus was stimulated using the on-chip Pt electrodes with current intensities from 200 μA to 1 mA. Furthermore, we have verified empirically that this technique has minimal effect on the hippocampus.Sensors and Actuators A: Physical.