To formulate and test hypotheses regarding modulation in cortex, we need quantitative data that reveal both local axon density and receptor subtype distribution. We use these anatomical data both to develop hypotheses and to interpret our data. We examine receptor localization using quantitative multi-label immunofluorescence confocal microscopy (for cell type and laminar localization), and quantitative immuno-electron microscopy (for localization to cellular compartment). We also conduct quantitative analyses of axon density by light and confocal microscopy and combine all of these techniques with tracer studies to understand the relationship between these structures (release and receptor sites) and the various pathways in cortex.
