Yaksh T L, Farb D H, Leeman S E, Jessell T M
Science. 1979 Oct 26;206(4417):481-3. doi: 10.1126/science.228392.
A single intrathecal injection of capsaicin depletes substance P from primary sensory neurons and causes a prolonged increase in the thermal and chemical pain thresholds of the rat but no apparent change in responses to noxious mechanical stimuli.