Vaginocervical stimulation attenuates the sensitization of appetitive sexual behaviors by estradiol benzoate in the ovariectomized rat.
The acute administration of estradiol benzoate (EB) to the ovariectomized (OVX) rat induces low levels of lordosis while sexually appetitive behaviors (e.g., hops, darts, solicitations) are absent, yet the repeated administration of EB results in a behavioral sensitization in which lordosis is potentiated and sexually appetitive behaviors are induced. We have shown that repeated copulation attenuates the sensitization of appetitive sexual behaviors. Here, we assessed which component of male stimulation during copulation is involved in the attenuation. On 8 occasions, sexually experienced OVX Long-Evans rats were treated with 10μgEB and 48h later assigned to one of six groups that differed in their experience on intermediates tests (2-7). One was given repeated access to a male (EB/Male), and another was placed in the copulation chamber alone (EB/Alone) on intermediate tests. Three groups were given one of three somatosensory stimuli by the experimenter: manual flank stimulation (FLS), clitoral stimulation (CLS), or vaginocervical stimulation (VCS). Finally, the control group was left undisturbed in the animal care facility (ACF). Sexual behaviors were measured on Tests 1 and 8. VCS received from the experimenter (VCS) or from the male during copulation (EB/Male) attenuated the magnitude of the sensitization of appetitive sexual behaviors compared with those that were not brought to the testing rooms (ACF), and the effect was most pronounced on sexual solicitations. These results suggest that VCS received during penile intromission inhibits the sensitization of sexually appetitive behaviors by repeated administration of EB. As such, repeated administration of EB may oppose those mechanisms that induce estrous termination, perhaps by sensitizing inhibitory processes within the ventromedial hypothalamus that typically prevent the display of sexual behaviors (i.e., by facilitating disinhibition).
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada. Electronic address: sljones@live.concordia.ca.
Sherri Lee
SL
Jones
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
Katuschia
K
Germé
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
M Dean
MD
Graham
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
Patrick
P
Roy
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
James
J
Gardner Gregory
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
Stephanie
S
Rosenbaum
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
Mayte
M
Parada
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada.
James G
JG
Pfaus
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology*; D002584:Cervix Uteri; D003307:Copulation / Q000187:drug effects / Q000502:physiology*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects; D005260:Female; D008297:Male; D010052:Ovariectomy; D010812:Physical Stimulation; D011187:Posture / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D012726:Sexual Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D014621:Vagina
C074283:estradiol 3-benzoate; D004958:Estradiol
Clitoral stimulation; Estradiol; Estrous termination; Flank stimulation; Rat; Sensitization; Sexual behavior; Vaginocervical stimulation