Raman microscopy of porcine inner retinal layers from the areacentralis

[摘要] Purpose: To characterize the Raman spectra of porcine inner retinallayers, specifically, the inner nuclear, inner plexiform, ganglion cell,and nerve fiber layers.Methods: Raman microscopy was employed at three excitationwavelengths, 785, 633, and 514 nm to measure Raman spectra in a highresolution grid across the inner layers of 4% paraformaldehydecryoprotected porcine retina. Multivariate statistics were used tosummarize the principal spectral signals within those layers and to mapthe distribution of each of those signals.Results: The detected Raman scattering was dominated by a signalcharacteristic of the protein population present in each layer. Asexpected, a significant nucleotide contribution was observed in theinner nuclear layer, while the inner plexiform layer displayed a minorcontribution from fatty acid based lipid, which would be characteristicof the axonal and synaptic connection resident in this layer. Bloodvessels were readily characterized by their distinct heme-derivedspectral signature, which increased at 633 and 514 nm excitationcompared to 785 nm. Discrete isolated nucleotide signals were identifiedin the ganglion cell layer, while the nerve fiber layer exhibited ahomogenous profile, which is indicative of its broadly uniform axonaland cytoplasmic Muller cell components.Conclusions: The present study demonstrated the potential of Ramanmicroscopy as a tool to study the biochemical composition ofpathologically normal retina. Specifically, the method allowed a uniquemethod of analyzing the network of neurons involved in relayinginformation from the photoreceptor population to the ganglion cellderived nerve fiber layer. The study has demonstrated the ability ofRaman microscopy to generate simultaneously information on a range ofspecific biochemical entities within the stratified normal retina.

[学科分类] 生物化学/生物物理