TABLE 2

Nociceptive phenotypes of mice lacking the NOP receptor or the ppN/OFQ polypeptide


ppN/OFQ-/-

Antinociceptive (higher stress-induced analgesia in group house males) in the tail-flick test; no nociceptive phenotype in individually housed males

Köster et al. (1999)
Tail-flick test, antinociceptive in young mice (6-8 weeks), but hyperalgesic in adult mice (>12 months) Mogil and Pasternak (2001)
Unchanges tolerance to morphine Kest et al. (2001)
Normal responses in phase I, but increased responses in phase II of the formalin test, increased thermal sensitivity after zymosan A injection Depner et al. (2003)
NOP-/- No nociceptive phenotype in the tail-flick and acetic acid writhing test Nishi et al. (1997)
No nociceptive phenotype tail-flick and tail pintch test; no nociceptive phenotype hot plate, tail-flick, electric foot shock, acetic acid writhing test Ueda et al. (1997) Mamiya et al. (1998)
Increased nociceptive flexor responses upon intraplantar injection of bradykinin or substance P Inoue et al. (2003)

Normal responses in phase I, but increased responses in phase II of the formalin test, increased thermal sensitivity after zymosan A injection
Depner et al. (2003)