Terahertz spectroscopy of snap-frozen human brain tissue: an initial study

A report is presented of a novel study on the use of terahertz (THz) spectroscopy to distinguish between healthy and diseased snap-frozen tissue samples obtained from three regions of the human brain. The diseased tissue samples are neuropathologically diagnosed as containing abnormally high numbers of protein plaques consistent with Alzheimer's disease. As protein structures have been successfully probed elsewhere using THz radiation, it is expected that the collective vibrational modes of protein plaques can be detected in the THz frequency range. Furthermore, measurements of frozen samples assist in removing uncertainties caused by the presence of water in the sample. Results show some distinction in the THz absorption spectra, which could be attributed to pathological changes in the diseased tissue.