Figure 1
NPS effects on audible vocalizations. Audible vocalizations were evoked by brief (15 s) innocuous (300 g/30 mm2, A, B) and noxious (1200 g/30 mm2, C, D) stimulation of the knee joint in normal and arthritic rats. Duration of vocalizations during a 1 min period was measured before (Pre) and 45 min after nasal application of saline (Sal; n = 6 normal rats; n = 9 arthritis rats) or before (Pre) and 45 min after NPS (14 nmol; n = 6 normal rats; n = 8 arthritic rats). NPS had significant inhibitory effects in the arthritic pain model. *,** P < 0.05, 0.01, unpaired t-test.