Yawning and Penile Erection Frequencies Are Resilient to Maternal Care Manipulation in the High-Yawning Subline of Sprague–Dawley Rats

Yawning is a stereotyped behavioral pattern characterized by wide open of the mouth associated with a deep inspiration followed by short expiration and it is present in all vertebrate species with low frequency. In rats it has been associated with penile erections spontaneously or after D2-like dopaminergic agonists administration. We selectively bred a high-yawning (HY) subline from Sprague-Dawley rats (SD) that yawned 20 times/h, that is one...