[An application of the fibered fluorescence microscopy to continuously monitor the rat cerebral neurons in vivo].

The aim of the present study was to establish an approach to continuously record fluorescent signals of rat cerebral cortical neurons in vivo, using the novel system composed of fiber-optic probe and fluorescence microscopy. To visualize cortical neurons, recombinant virus vectors carrying green fluorescent protein (GFP) gene were microinjected into cerebral cortex in Sprague Dawley (SD) rats. Seven days later, imaging microprobe, composed of optical minifibers, was inserted into the microinjected region of cerebral cortex. By using the fibered fluorescence microscopy, we observed fluorescent signals of cortical neurons transfected with GFP in living animals. In the brain slices from the microinjected region, the fluorescence signals of GFP were recorded using fluorescence microscopy, which confirmed the observation of the fibered fluorescence microscopy. The novel technology established in the present study maintains physical condition of experimental animal, and meets the demands of fluorescence micro-imaging in neural tissue in vivo. Application of this technology allows a direct and rapid approach tracing fluorescent signals of neurons in living animals.