SP-CTA is an exciting tool for use in the research of neurokinin (NK-1) receptor-expressing cells of the central nervous system. It can be used very effectively in vivo for increasing sensitization of these neuronal cells. Selectively targeting the NK-1r-expressing cells with the substance P moiety allows the researcher to stimulate only the cells of interest by amplifying their cAMP production with the CTA, without altering the neighboring cells. This effect lasts for a few days, and gives the researcher an opportunity to study behaviors such as those related to the perception of pain or the control of breathing.
SP-CTA is a chemical conjugate of the neuropeptide substance P and the catalytic A subunit of cholera toxin. It stimulates cells expressing the substance P receptor.