Lordosis in response to manual palpation of the flanks and perineum was markedly facilitated by simultaneously probing the vaginal cervix. While palpation without cervical probing never induced lordosis in 96 ovariectomized, hormone-untreated rats, addition of cervical probing induced lordosis in 48% of these individuals. Cervical probing alone never induced lordosis. Estrogen administration (as little as a single injection of 1.0 μg/100 g body wt) significantly increased the intensity (extent of dorsiflexion, measured photographically), and probability of occurrence, of lordosis in response to palpation with cervical probing. Lordosis in response to mounting attempts by males, or by palpation alone, occurred only rarely at estrogen dosages lower than 10.0 μg/100 g body wt. Lordosis intensity and probability of occurrence varied significantly in relation to the estrous cycle; they were higher in proestrus and the transitional periods of diestrus-proestrus and proestrus-estrus, than in estrus, metestrus or diestrus. These findings demonstrate that cervical probing with manual palpation is a “supernormal” stimulus for inducing lordosis, and that neural mechanisms involved in lordosis remain functional in the absence of ovarian hormones. (Endocrinology93: 548, 1973)
No takes yet. Share an insight, caveat, or question.
Komisaruk et al. (1973) studied this question.