Research ArticleArticle
Spinal Antinociceptive Synergism between Morphine and Clonidine Persists in Mice Made Acutely or Chronically Tolerant to Morphine
Carolyn A. Fairbanks and George L. Wilcox
Journal of Pharmacology and Experimental Therapeutics March 1999, 288 (3) 1107-1116;