Lordosis response components can be elicited in decerebrate rats by combined flank and cervix stimulation

Previous research has indicated that chronically decerebrate adult female rats are incapable of exhibiting lordosis in response to lumbosacral somatic stimuli, suggesting a dependency of this response on forebrain influence. Since vaginocervical stimulation facilitates lordosis to lumbosacral stimuli in rats, the present study investigated the possibility that chronically decerebrate rats could show lordosis in response to flank palpation if vaginocervical pressure was applied concurrently. Six of nine ovariectomized, decerebrate rats exhibited a coordinated display of lordosis-like responses to flank palpation if this stimulus was accompanied by vaginocervical stimulation, but not in response to flank and perineal pressure alone. Estradiol-progesterone treatment increased the magnitude of the response in five of six animals. As in intact rats, cervix pressure in the decerebrates also produced immobilization and blocked responses to nociceptive stimuli. Thus, the caudal neuraxis can mediate expression of essential components of the lordosis response in the absence of forebrain influence.