“Electrophysiological, neurochemical, and behavioral studies have shown that cannabinoids (marijuana-like drugs) suppress pain neurotransmission…

We think that these results have implications for how cannabinoids may work in chronic pain states. A differential anatomical basis underlying cannabinoid and mu opioid modulation of primary afferent transmission is supported. Whereas mu opioid receptors in spinal cord are associated predominantly with thin-diameter primary afferents, cannabinoid receptors are localized to both thin and coarse diameter fibers.

These differences may provide a basis for the possibility that cannabinoids may relieve pain when traditional opiate drugs fail.”

Jan. 25, 2002