There's a release of norepinephrine from the descending inhibitory bulbospinal neurons that binds to alpha-two-receptors within the dorsal horn to decrease afferent suffering transmission and generate analgesia. Thus, drugs like clonidine that target alpha-two receptors can affect the transmission of pain. Clonidine treats large hypertension by stimulating αtwo receptors https://www.proleviate.com/post/the-new-pain-killer-conolidine