Central administration of oxytocin differentially increases yawning, penile erections and scratching in high- (HY) and low-yawning (LY) sublines of Sprague-Dawley rats

Oxytocin produced a dose-dependent increase in yawning and penile erection frequencies and this effect was significantly higher in the HY, compared to the LY, subline. However, the number of oxytocin-induced scratching bouts was significantly higher in the LY, compared to the HY group. In conclusion, these sublines represent a suitable model for detailed analysis of behavior induced by oxytocin and other neuropeptides in animals with different spontaneous expression of behavioral traits.