Spatial quantification of single cell mRNA and ligand binding of the kappa opioid receptor in the rat hypothalamus.

Detailed quantification of brain tissue provides a deeper understanding of changes in expression and function. We have created a pipeline to study the detailed expression patterns of the kappa opioid receptor in the rat hypothalamus using high resolution fluorescence microscopy and receptor autoradiography. The workflow involved structured serial sampling of rat hypothalamic nuclei, in situ detection of mRNA and receptor expression, and advanced image analysis. Our results demonstrate how maintaining spatial information can lead to increased understanding of RNA and protein expression. In addition, we show the detailed expression patterns of the kappa opioid receptor in the rat hypothalamus.