 Currently, these treatments must be re-administered on a regular (albeit infrequent) schedule in order to maintain their analgesic effects.Certain metabolites of polyunsaturated fatty acids have been shown to stimulate cells in a TRPV1-dependent fashion.The metabolites of linoleic acid, including 13("S")-hydroxy-9Z,11E-octadecadienoic acid (13(S)-HODE), 13("R")-hydroxy-9Z,11E-octadecadienoic acid (13("R")-HODE, 9("S")-hydroxy-10(E),12(Z)-octadecadienoic acid (9("S")-HODE), 9("R")-hydroxy-10(E),12(Z)-octadecadienoic acid (9("R")-HODE), and their respective keto analogs, 13-oxoODE and 9-oxoODE (see 13-HODE and 9-HODE sections on Direct actions), activate peripheral and central mouse pain sensing neurons.