Types of skin afferent fibers and spinal opioid receptors that contribute to touch-induced inhibition of heart rate changes evoked by noxious cutaneous heat stimulation

Conclusions: Microcone touch induced greater responses of low-threshold mechanoreceptive A? and C afferent units than control touch. The antinociceptive effect of microcone touch was abolished by intrathecal injection of ?-opioid receptor antagonist. These results suggest that excitation of low-threshold mechanoreceptive A? and C afferents produces the release of endogenous ?-opioid ligands in the spinal cord, resulting in the inhibition of nociceptive transmission that contributes to somatocardiac reflexes.
Source: Molecular Pain - Category: Molecular Biology Authors: Source Type: research