Fiber-optic time-resolved fluorescence sensor in vivo measurements in the brain of rat unanesthetized and freely moving.
Abstract
A previously unreported nanosecond time resolved fluorescence from the nucleus raphe dorsalis (n.RD) of rats in chronic conditions is presented. The excitation is provided by a subnanosecond nitrogen laser (337 nm) and transmitted through a single optical fiber (diameter=200 µm). The fluorescence emission spectrum collected through the same fiber, exhibits two maxima at 400 nm and 460 nm. Spectral correlation from in vivo and in vitro spectra suggested that the spectral peak found in the n.RD, occurring with a maximum in the 460 nm range, may arise from an endogenous NADH fluorescence.