Spectroscopic imaging with spectral domain visible light optical coherence microscopy in Alzheimer's disease brain samples.

A visible light spectral domain optical coherence microscopy system was developed. A high axial resolution of 0.88 in tissue was achieved using a broad visible light spectrum (425 - 685 ). Healthy human brain tissue was imaged to quantify the difference between white (WM) and grey matter (GM) in intensity and attenuation. The high axial resolution enables the investigation of amyloid-beta plaques of various sizes in human brain tissue and animal models of Alzheimer's disease (AD). By performing a spectroscopic analysis of the OCM data, differences in the characteristics for WM, GM, and neuritic amyloid-beta plaques were found. To gain additional contrast, Congo red stained AD brain tissue was investigated. A first effort was made to investigate optically cleared mouse brain tissue to increase the penetration depth and visualize hyperscattering structures in deeper cortical regions.