Electrical low-frequency stimulation (LFS) of cutaneous afferents elicits long-term depression (LTD) of craniofacial nociception and pain (Ellrich 2006).The study addresses spatial organization of LTD within one side of the face. The blink reflex (BR) was evoked by electrical test stimulation of the supraorbital nerve area before and after conditioning LFS in 10 healthy volunteers. Noxious LFS (1 Hz) was applied to supraorbital (sLFS), infraorbital (iLFS), or mental (mLFS) nerve areas. All stimuli were applied to the same side of the face with intensities of 3times pain threshold. Volunteers rated the test stimulus intensity. Each volunteer participated in 4 sessions with sLFS, iLFS, mLFS, or without LFS (Control). Pain ratings of electrical test stimulation were differently affected in experimental sessions (p<0.01) with strongest reduction by -19.6% after sLFS. BR integral decreased by -34.7% significantly stronger after sLFS than in all other experimental conditions (p<0.001). Electrical pain thresholds increased significantly stronger in sLFS than in iLFS, mLFS, and Control (p<0.001). Trigeminal nociception and pain were inhibited by homotopic LFS at the forehead but not after heterotopic LFS in infraorbital and mental nerve areas. Homotopic organization of ipsilateral trigeminal LTD in man may have implications for future neuromodulatory treatment of chronic craniofacial pain. Reference: Ellrich, J. 2006. Suppl Clin Neurophysiol 58, 195–208