Fiber optic based multisensor to brain neurons in awake animals

The fibeated broptic-based multisensor was made of quartz optic fiber capillary with an outer diameter of 250 ??m and an inner diameter of 10 ??m through two methods: a capillary and the parallel capillary with another piece of optic fiber. There was a thin layer of tungsten membrane (thickness 1 ??m) around the outer surface of the optic fiber or capillary. The metal membrane worked as a micro electrode or an electro-osmosis electrode. Nitrogen laser beam and laser-fluorescent pulses were guided in two ways through optic fiber or the wall of the capillary. The advantage of one capillary was its small tip and measurement of different physiological indices in the same site, but the intensity of laser-fluorescent pulses was diminished by electro-osmosis flow; the parallel optic fiber and capillary avoided the shortage, but the device tip was bigger than a capillary. The multisensor was used to inquire into cognitive brain mechanism in awake animals by simultaneous recording of neuron activities (neuron firing), neuron metabolism rate (laser-fluorescent pulses), and biochemical events through microelectrophore in vivo and field effect electro-osmosis analysis at situ. The effects of nitric oxide biosynthesis-related compounds on neuron efficiency of the cortex were investigated by the multisensor.EI