Spinal pain suppression mechanisms may differ for phasic and tonic pain.
The dorsolateral funiculus (DLF) spinal pathway has previously been identified as a major pathway involved in descending modulation of pain. While bilateral lesions of the DLF attenuated systemic morphine analgesia as measured by the tail-flick test, they failed to attenuate analgesia as measured by the formalin test. These results suggest that phasic and tonic pain, modeled by the tail-flick and formalin tests, respectively, may utilize different pain suppression mechanisms.
D000818:Animals; D004525:Efferent Pathways / Q000503:physiopathology; D008297:Male; D008722:Methods; D009020:Morphine / Q000627:therapeutic use; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D051381:Rats; D013116:Spinal Cord / Q000503:physiopathology*
D009020:Morphine