We have developed to observe neural activities in the deep brain of a freely moving mouse with green fluorescent protein (GFP). We implanted a dedicated complementary metal oxide semiconductor (CMOS) imaging device into the hippocampus or the basal ganglion of an anesthetized mouse to confirm the effectiveness of the CMOS imaging device for the detection of GFP generated in the deep brain of the anesthetized mouse. Moreover, we conducted an experiment to demonstrate the capability of the CMOS imaging device to detect GFP in the deep brain of a freely-moving mouse. As a result of the in vivo experiments with two methods of GFP expression, we successfully detected the light intensity of GFP in the hippocampus or the basal ganglion of the anesthetized mouse. Furthermore, we demonstrated that the implanted CMOS imaging device operated well in the freely moving mouse after one week from implantation. We demonstrated the basic technology to realize the observation of neural activities in the deep brain of a freely moving mouse.

We have developed a multimodal complementary metal-oxide-semiconductor (CMOS) sensor device for observing neural activities in the deep brain of a mouse. The CMOS sensor includes an image sensor, electrodes, and a light-emitting diode (LED). The image sensor was designed to be operated using only four inputs/outputs (I/Os) to reduce the number of connecting wires. The electrodes were placed on the pixel array of the sensor. Windows were opened in the electrode over the photodiodes to enable the fluorescence to be imaged using the pixels under the electrodes. An LED was mounted on the chip. The sensor chip was shaped like a shank to facilitate smooth insertion into the brain tissue. The entire device was coated with a parylene layer to make it biocompatible. The experimental results showed that the green fluorescent beads on the pixel array were successfully imaged using the LED on the chip as a light source. In a brain phantom, the change in the electrical potential was successfully sensed by the electrode, and green fluorescent beads were simultaneously imaged using the pixels under the electrode. We also demonstrated that the CMOS sensor device could successfully operate in the hippocampal area of an anesthetized mouse.

PACS. 64.60.-i -General studies of phase transitions.Abstract. -The concentration-induced sequence of three incommensurate phases ( , 1 , 2 ) previously disclosed in LixV2O5 are interpreted as resulting from distinct Lifshitz-invariant and Lifshitz-points instabilities. When varying the temperature, the phase displays a reentrant behavior, which is described as a folding of the high-temperature region triggered by the ordering of the lithium ions.

We have developed a multimodal complementary metal oxide semiconductor (CMOS) sensor device embedded with Au electrodes for fluorescent imaging and cell stimulation in the deep brain of mice. The Au electrodes were placed on the pixel array of the image sensor. Windows over the photodiodes were opened in the electrode area for simultaneous fluorescent imaging and cell stimulation in the same area of the brain tissue. The sensor chip was shaped like a shank and was packaged by two packaging methods for high strength or minimal invasion. The experimental results showed that the 90 Â 90 mm 2 Au electrodes with windows were capable of injecting theta burst stimulation (TBS)-like current pulses at 0.2 -1 mA in a saline solution. We successfully demonstrated that fluorescent imaging and TBS-like current injection can be simultaneously performed in the electrode area of a brain phantom. #

We have developed CMOS based image sensing devices that can be implanted in a mouse deep brain to monitor the neural activities of a freely-moving mouse. Transgenic mice that express GFP (green fluorescence protein) in the midbrain DA (dopamine) neurons under the control of the rat TH (tyrosine hydroxylase) gene promoter, was used for the experiments. The fluorescence was measured through GFP which acts as the sensor for DA and successfully demonstrated that the implanted device can be used for monitoring the neural activities in long term. Also the next generation sensor which realizes more stable operation in the mouse brain is presented.