scholarly journals Selective Oxytocin Receptor Activation in the Ventrolateral Portion of the Ventromedial Hypothalamus Is Required for Mating-Induced Pseudopregnancy in the Female Rat

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 836-842 ◽  
Author(s):  
Lesley E. Northrop ◽  
Mary S. Erskine
Keyword(s):  
Sexual Behavior ◽  
Cerebral Spinal Fluid ◽  
Receptor Activation ◽  
Ventromedial Hypothalamus ◽  
Oxytocin Receptor ◽  
Spinal Fluid ◽  
Female Rats ◽  
Female Rat ◽  
Female Sexual Behavior ◽  
Cervical Stimulation

The ventrolateral region of the ventromedial hypothalamus (VMHvl) plays an essential role in female sexual behavior. Oxytocin (OT) is released from the paraventricular nucleus to downstream sites such as the VMHvl to facilitate female sexual behavior and shows characteristics of a prolactin (PRL)-releasing factor. During mating, vaginal cervical stimulation (VCS) received from a vasectomized male triggers twice-daily PRL surges that persist up to 12+ d, a period known as pseudopregnancy (PSP). To determine whether OT is involved in PSP by acting within the VMHvl, female rats were infused bilaterally with an oxytocin receptor antagonist (OTR-A), a vasopressin receptor-1a antagonist (V1a-A), or artificial cerebral spinal fluid 30 min before mating. All females received a sufficient amount of VCS, 15 intromissions, to induce PSP. Females infused with OTR-A (20 ng/0.4 μl) with implants targeting the VMHvl showed only a 22% induction of PSP, as measured using vaginal diestrus and serum PRL concentrations. In contrast, controls and V1a-A (80 ng/0.4 μl) infused females exhibited 100% induction of PSP. Females infused with OTR-A returned to estrus after 5 d, whereas females infused with either artificial cerebral spinal fluid or V1a-A remained in diestrus for 12–13 d in both the correct and missed placement groups. Although OT can act as a PRL releasing factor, the PRL surge does not begin until 18–24 h after mating. Together, our results suggest that OT release in the VMHvl mediates the effects of VCS on the induction of the PRL secretion needed to establish PSP.

Sexual Behavior is Enhanced by Regular, Repeated Mating from Young Adulthood to Middle Age in Female Long-Evans Rats

2020 ◽  
Vol 13 (2) ◽  
pp. 169-177
Author(s):  
Fay A. Guarraci ◽  
Chantal M.F. Gonzalez ◽  
Devon Lucero ◽  
Lourdes K. Davis ◽  
Sarah H. Meerts
Keyword(s):  
Sexual Behavior ◽  
Mating Behavior ◽  
Preference Test ◽  
Sexual History ◽  
Female Rats ◽  
Male Rat ◽  
Female Rat ◽  
Repeated Mating ◽  
First Time ◽  
Mating Tests

Background: Aging is associated neuroendocrine changes in women. Animals can be used to model these changes, as well as changes in reproductive behavior. Objective: The current study was designed to characterize mating behavior across age and assess the effects of age and sexual history on mating behavior. Methods: Sexual motivation was assessed using the partner-preference test, in which a female rat is given the choice to interact with a same-sex conspecific or a sexually-vigorous male rat, with which she can mate. Results: Across repeated mating tests (2-12 months of age), female rats spent more time with the male, displayed more solicitation behaviors, were less likely to leave the male after mounts, but visited both stimulus animals less frequently. Comparing a separate group of age-matched, hormoneyoked female rats mated for the first time at 12 months of age to female rats mated for the first time at 2 months of age showed that the 12 month rats visited both stimulus animals less, were less likely to leave the male after mounts, took longer to return to the male after mounts, and displayed fewer solicitation behaviors than their younger counterparts. Relative to middle-aged female rats once they were sexually experienced, 12 month naïve rats spent less time with the male, were more likely to leave the male after mounts, and displayed fewer solicitation behaviors. Furthermore, 12 month naïve rats failed to discriminate between the stimulus animals, visiting both stimulus animals at the same rate unlike 2 month naïve or 12 month experienced rats. Conclusion: Taken together, these results suggest that aging affects some measures of sexual behavior, but most effects of age can be mitigated by regular, repeated mating.

Progesterone-dependent sexual behavior and protein patterns in the ventromedial hypothalamus of the adult female rat

1991 ◽  
Vol 2 (6) ◽  
pp. 491-500
Author(s):  
Michelle E. Montemayor ◽  
Carol S. Giometti ◽  
John Taylor ◽  
Edward J. Roy
Keyword(s):  
Sexual Behavior ◽  
Adult Female ◽  
Ventromedial Hypothalamus ◽  
Female Rat ◽  
Protein Patterns

scholarly journals Female rat sexual behavior is unaffected by perinatal fluoxetine exposure

2020 ◽  
Author(s):  
Jan Hegstad ◽  
Patty T. Huijgens ◽  
Danielle J. Houwing ◽  
Jocelien D.A. Olivier ◽  
Roy Heijkoop ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Early Development ◽  
Adult Female ◽  
Sexual Behaviors ◽  
Expression Patterns ◽  
Estrogen Receptor Α ◽  
Serotonin Release ◽  
Conflict Behavior ◽  
Female Rat ◽  
Female Sexual Behavior

AbstractSerotonin plays an important role in adult female sexual behavior, however little is known about the influence of serotonin during early development on sexual functioning in adulthood. During early development, serotonin acts as neurotrophic factor, while it functions as a modulatory neurotransmitter in adulthood. The occurrence of serotonin release, could thus have different effects on behavioral outcomes, depending on the developmental period in which serotonin is released. Because serotonin is involved in the development of the HPG axis which is required for puberty establishment, serotonin could also alter expression patterns of for instance the estrogen receptor α (ERα).The aim of our study was to investigate the effects of increased serotonin levels during early development on adult female rat sexual behavior during the full behavioral estrus in a seminatural environment. To do so, rats were perinatally exposed with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (10 mg/kg FLX) and sexual performance was tested during adulthood. All facets of female sexual behavior between the first and last lordosis (behavioral estrus), and within each copulation bout of the behavioral estrus were analyzed. Besides the length and onset of the behavioral estrus and the sexual behaviors patterns, other social and conflict behavior were also investigated. In addition, we studied the effects of perinatal FLX exposure on ERα expression patterns in the medial preoptic nucleus, ventromedial nucleus of the hypothalamus, medial amygdala, bed nucleus of the stria terminalis, and the dorsal raphé nucleus.The results showed that perinatal fluoxetine exposure has no effect on adult female sexual behavior. The behavioral estrus of FLX-females had the same length and pattern as CTR-females. In addition, FLX- and CTR-females showed the same amount of paracopulatory behavior and lordosis, both during the full behavioral estrus and the “most active bout”. Furthermore, no differences were found in the display of social and conflict behaviors, nor in ERα expression patterns in the brain. We conclude that increases in serotonin levels during early development do not have long-term consequences for female sexual behavior in adulthood.

scholarly journals Localized actions of progesterone in hypothalamus involve oxytocin

1989 ◽  
Vol 86 (17) ◽  
pp. 6798-6801 ◽  
Author(s):  
M Schumacher ◽  
H Coirini ◽  
M Frankfurt ◽  
B S McEwen
Keyword(s):  
Receptor Binding ◽  
Fold Increase ◽  
Ovarian Hormones ◽  
Estradiol Benzoate ◽  
Ventromedial Hypothalamus ◽  
Oxytocin Receptor ◽  
Behavioral Effects ◽  
Female Rat ◽  
Surrounding Area ◽  
Oxytocin Receptors

Two ovarian hormones, estradiol and progesterone, which facilitate mating behavior in the female rat by acting on the ventromedial nuclei (VMN) of the hypothalamus, induce changes in oxytocin receptor binding in this brain region. Estradiol induced a 4-fold increase in the oxytocin receptor binding of the VMN and surrounding area and increased the number and immunostaining of oxytocin fibers in an area lateral to the ventral VMN. Progesterone, in estrogen-primed rats, caused the induced oxytocin receptors to spread over the area containing the oxytocin fibers. Infusion of oxytocin into the ventromedial hypothalamus increased the display of lordosis behavior only in females primed with both estradiol benzoate and progesterone. Thus, the sequential actions of two ovarian hormones bring a neuropeptide and its receptors into register and enable the neuropeptide to exert behavioral effects.

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