Infrared microspectroscopic imaging of the cerebellum of normal and cytarabine treated rats

Conventionally, the diagnosis of neuropathology in a subject requires the identification of a behavioral modification, which provides direction for appropriate histological analyses. However, since the ultimate diagnosis of the pathology largely depends on the initial choice of histological tests, the opportunity exists for inaccurate or insensitive results. An innovative approach using Fourier transform infrared (FT-IR) spectroscopic imaging to diagnose neuropathology should prove useful. This novel method monitors and visualizes the underlying chemistry of the tissue, based on hundreds of vibrational absorption bands that are intrinsic to the sample. As such, it makes no prior assumptions as to the type or degree of pathology. Using this technique, we have spectroscopically imaged cerebellar tissue slices from rats [control subjects and subjects treated with the antineoplastic drug, cytarabine (Ara-C)], and have been able to correlate lipid and protein distributions within distinct cell types in the cerebellum. A further benefit of the technique is that it simultaneously records tens of thousands of independent spectra from different spatial locations within the sample. Thus, a variety of statistical and multivariate techniques can be exploited to characterize large sample areas and to provide robust classification of individual spectral signatures. In comparison to standard histological protocols, FT-IR spectroscopic imaging simultaneously analyzes cell layers and identifies subtle structural and biochemical changes within the sample. We suggest that FT-IR spectroscopic imaging should provide a highly reliable, complementary tool for standard histological tier testing.