Lemons LL, Chatterjee K, Wiley RG (2010) Neuropeptide receptor co-expression in superficial dorsal horn: Effects of galanin-saporin, neuropeptide y-saporin and dermorphin-saporin. Neuroscience 2010 Abstracts 585.5/XX19. Society for Neuroscience, San Diego, CA.
Summary: We have previously shown that the role of specific neurons in behavioral processes can be fruitfully studied using targeted toxins. Toxins composed of a targeting neuropeptide coupled to the ribosomal-inactivating toxin, saporin, are used to selectively destroy superficial dorsal horn neurons expressing the cognate peptide receptors followed by assessment of changes in pain behavior. In the present study, we sought to compare the anatomic effects of three closely related targeted toxins, each with different nocifensive behavioral effects. Rats were given single lumbar intrathecal injections of either galanin-saporin (Gal-SAP), neuropeptide Y-saporin (NPY-SAP), or dermorphin-saporin (Derm-SAP). Lumbar spinal cord sections from each rat were stained for each of the three receptors, GalR-1, Y1R and MOR (mu opiate) using standard immunoperoxidase technique. Each toxin produced a significant decrease in staining for its cognate receptor. Gal-SAP animals showed no change in either MOR or Y1R staining. NPY-SAP rats showed decreased staining for both GalR1 and MOR, and Derm-SAP rats were assessed for changes in expression of GalR1 and Y1R. These findings suggest overlaps between the populations of neurons that express the GalR1, Y1R, and MOR. Specifically, Y1R-expressing neurons also express GalR1 and MOR, probably by separate subpopulations of Y1R neurons. The results also suggest either that Gal-SAP only kills neurons that do not express either of the other two receptors, or some of the observed loss of receptors after NPY-SAP is due to secondary (transsynaptic) effects. Double- and triple-label fluorescent immunohistochemistry will be used to directly visualize receptor co-expression patterns and targeted toxin effects. These results will be valuable in interpreting the unique nocifensive behavioral effects of each of these targeted toxins.
Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Galanin-SAP (Cat. #IT-34), NPY-SAP (Cat. #IT-28)