Alzheimer mouse brain tissue measured by time resolved fluorescence spectroscopy using single- and multi-photon excitation of label free native molecules.

Time resolved spectroscopic measurements with single-photon and multi-photon excitation of native molecules were performed ex vivo on brain tissues from an Alzheimer's disease (AD) and a wild type (WT) mouse model using a streak camera. The fluorescence decay times of native NADH and FAD show a longer relaxation time in AD than in WT tissue, suggesting less non-radiative processes in AD. The longer emission time of AD may be attributed to the coupling of the key native building block molecules to the amyloid-tau and/or to the caging of the native fluorophores by the deposition of amyloid-beta or tau plaques and neurofibrillary tangles that affect the local non-radiative interactions.