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Larry J Young - One of the best experts on this subject based on the ideXlab platform.

  • Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole
    Neuropsychopharmacology, 2015
    Co-Authors: Meera E Modi, Catherine E. Barrett, Kara A Kittelberger, Daniel G Smith, Rainer Landgraf, Kiyoshi Inoue, Larry J Young
    Abstract:

    The central melanocortin (MC) system has been widely studied for its effects on food intake and sexual behavior. However, the MC system, and more specifically the MC4 receptor (MC4R), also interacts with neurochemical systems that regulate socioemotional behaviors, including oxytocin (OT) and dopamine. In monogamous prairie voles, OT and dopamine interact to promote Partner Preference formation, a laboratory measure of an enduring social bond between mates. Here we investigated the effects of MC receptor activation on Partner Preference formation in prairie voles, as well as the interaction between the MC and OT systems during this process. Peripheral administration of the brain penetrant MC3/4R receptor peptide agonist, Melanotan II (MTII), and the highly selective, small-molecule MC4R agonist, Pf-446687, enhanced Partner Preference formation in the prairie vole, but not in the non-monogamous meadow vole. MTII-induced Partner Preferences were enduring, as they were present 1 week after drug manipulation. The prosocial effects of MCR agonists may be mediated, in part, through modulation of OT, as coadministration of an OT receptor antagonist prevented MTII-induced Partner Preferences. MTII also selectively activated hypothalamic OT neurons and potentiated central OT release. As OT has been shown to enhance some aspects of social cognition in humans, our data suggest that the MC4R may be a viable therapeutic target for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia, potentially through activation of the OT system.

  • increasing oxytocin receptor expression in the nucleus accumbens of pre pubertal female prairie voles enhances alloparental responsiveness and Partner Preference formation as adults
    Hormones and Behavior, 2011
    Co-Authors: Alaine C Keebaugh, Larry J Young
    Abstract:

    Oxytocin receptors (OXTR) in the nucleus accumbens (NAcc) promote alloparental behavior and Partner Preference formation in female prairie voles. Within the NAcc there is significant individual variation in OXTR binding and virgin juvenile and adult females with a high density of OXTR in the NAcc display an elevated propensity to engage in alloparental behavior toward novel pups. Over-expression of OXTR in the NAcc of adult female prairie voles using viral vector gene transfer facilitates Partner Preference formation, but has no effect on alloparental behavior, even though OXTR antagonists infused into the NAcc blocks both behaviors. We therefore hypothesized that long-term increases in OXTR signaling during development may underlie the relationship between adult OXTR density in the NAcc and alloparental behavior. To test this hypothesis, we used viral vector gene transfer to increase OXTR density in the NAcc of prepubertal, 21 day old female prairie voles and tested for both alloparental behavior and Partner Preference formation as adults. Consistent with a developmental impact of OXTR signaling, adults over-expressing OXTR from weaning display both increased alloparental behavior and Partner Preference formation. Thus, the relatively acute impact of elevated OXTR signaling in the NAcc on Partner Preference formation previously reported appears to be dissociable from the effects of longer term, developmentally relevant OXTR signaling necessary for modulating alloparental behavior. These results are consistent with the hypothesis that oxytocin can have both long-term “organizational” effects as well as acute “activational” effects on affiliative behaviors.

  • activation of μ opioid receptors in the dorsal striatum is necessary for adult social attachment in monogamous prairie voles
    Neuropsychopharmacology, 2011
    Co-Authors: James P. Burkett, Lauren L Spiegel, Anne Z Murphy, Kiyoshi Inoue, Larry J Young
    Abstract:

    Despite significant evidence that opioids are involved in attachment by mediating social reward and motivation, the role of opioids in the formation of adult social attachments has not been explored. We used the socially monogamous prairie vole (Microtus ochrogaster) to explore the role of endogenous opioids in social bonding by examining Partner Preference formation in female prairie voles. We hypothesized that μ-opioid receptors (MORs) in the striatum have a critical role in Partner Preference formation. We therefore predicted that peripheral administration of an opioid receptor antagonist would inhibit Partner Preference formation, and more specifically, that μ-opioid selective receptor blockade within the striatum would inhibit Partner Preference formation. To test our hypotheses, we first administered the non-selective opioid antagonist naltrexone peripherally to females during an 18-h cohabitation with a male and later tested the female with a Partner Preference test (PPT). Females showed a dose schedule-dependent decrease in Partner Preference in the PPT, with females in the continuous dose group displaying stranger Preferences. Next, we administered microinjections of the MOR selective antagonist -Phe-Cys-Tyr--Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) into either the nucleus accumbens shell (NAS) or the caudate-putamen (CP) immediately before a 24-h cohabitation with a male, and later tested the female with a PPT. Females receiving CTAP into the CP, but not the NAS, showed no Preference in the PPT, indicating an inhibition of Partner Preference formation. We show here for the first time that MORs modulate Partner Preference formation in female prairie voles by acting in the CP.

  • Central vasopressin V1a receptor activation is independently necessary for both Partner Preference formation and expression in socially monogamous male prairie voles.
    Behavioral neuroscience, 2010
    Co-Authors: Zoe R. Donaldson, Lauren L Spiegel, Larry J Young
    Abstract:

    The neuropeptide arginine vasopressin (AVP) modulates a variety of species-specific social behaviors. In socially monogamous male prairie voles, AVP acts centrally via vasopressin V1a receptor (V1aR) to facilitate mating induced Partner Preferences. The display of a Partner Preference requires at least 2 temporally distinct processes: social bond formation as well as its recall, or expression. Studies to date have not determined in which of these processes V1aR acts to promote Partner Preferences. Here, male prairie voles were administered intracerebroventricularly a V1aR antagonist (AVPA) at different time points to investigate the role of V1aR in social bond formation and expression. Animals receiving AVPA prior to cohabitation with mating or immediately prior to Partner Preference testing failed to display a Partner Preference, while animals receiving AVPA immediately after cohabitation with mating and control animals receiving vehicle at all 3 time points displayed Partner Preferences. These results suggest that V1aR signaling is necessary for both the formation and expression of Partner Preferences and that these processes are dissociable.

  • evaluation of two automated metrics for analyzing Partner Preference tests
    Journal of Neuroscience Methods, 2009
    Co-Authors: Todd H Ahern, Meera E Modi, James P. Burkett, Larry J Young
    Abstract:

    The Partner Preference test (PPT) is commonly used to examine sexual and social Preferences in rodents. The test offers experimental subjects a choice between two stimulus animals, and time spent with each is used to calculate a Preference score. In monogamous prairie voles (Microtus ochrogaster), the PPT has been paramount to the study of pair bonding. Although powerful, use of the PPT in voles has depended primarily on human manual scoring. Manual scoring is time-consuming and is susceptible to bias and fatigue, limiting the use of the PPT in high-throughput studies. Here we compared manual scoring (real-time and 16x) and two automated scoring metrics: "social proximity" and "immobile social contact". We hypothesized that "immobile social contact" would provide data most comparable to manually scored "huddling", and thus be the most sensitive measure of Partner Preference in prairie voles. Each automated metric produced data that highly correlated with manual scoring (R>0.90); however, "immobile social contact" more closely reflected manually scored huddling (R=0.99; P<0.001). "Social proximity" and "immobile social contact" were then used to detect group Partner Preferences in four data sets that varied by cohabitation length and sex. "Immobile social contact" revealed a significant Partner Preference in each data set; "social proximity" detected Partner Preferences in only three of the four. Our results demonstrate the utility of automated systems in high-throughput PPTs, and further confirm that automated systems capable of scoring "immobile social contact" yield results indistinguishable from manual scoring.

Elizabeth Adkins-regan - One of the best experts on this subject based on the ideXlab platform.

  • Sexual and pairing Partner Preference in birds and other animals.
    Hormones and behavior, 2019
    Co-Authors: Elizabeth Adkins-regan
    Abstract:

    Abstract Research on hormonal involvement in animals' Preferences for mating or pairing with same- or other-sex Partners has been among the topics featured in Hormones and Behavior over the years. In several species of non-pair-forming mammals, there is good evidence that the early sex steroid environment has an organizational effect on later sexual Partner Preference. Research with zebra finches, a pair-forming species, shows a likely early estrogenic organizational hormone effect on pairing Partner Preference, an effect that can also interact with the early social environment to determine adult pairing Preference. Experiments with two amphibian and fish species suggest that activational hormone effects (effects of the hormone milieu in adulthood) may regulate sexual Partner Preference. As a complement to the research on hormonal involvement, a growing body of theoretical and empirical research addresses the possible adaptive functions of the same-sex sexual and pairing behavior observed in many wild animals. Such advances have important implications for conceptualizing neuroendocrine mechanisms of Partner Preferences.

  • Neuroendocrine contributions to sexual Partner Preference in birds
    Frontiers in neuroendocrinology, 2011
    Co-Authors: Elizabeth Adkins-regan
    Abstract:

    A majority of birds are socially monogamous, providing exceptional opportunities to discover neuroendocrine mechanisms underlying Preferences for opposite-sex Partners where the sexes form extended affiliative relationships. Zebra finches have been the focus of the most systematic program of research to date in any socially monogamous animal. In this species, sexual Partner Preference can be partially or largely sex reversed with hormone manipulations during early development, suggesting a role for organizational hormone actions. This same conclusion emerges from research with Japanese quail, which do not form long-term pairs. In zebra finches, social experience manipulations during juvenile development also can sex reverse Partner Preference, either alone or in combination with an early hormone manipulation. Although there are several candidate brain regions where neural mechanisms could underlie these effects of hormones or social experience, the necessary research has not yet been done to determine their involvement. The neuroendocrinology of avian sexual Partner Preference is still frontier territory.

  • Development of Sexual Partner Preference in the Zebra Finch: A Socially Monogamous, Pair-Bonding Animal
    Archives of Sexual Behavior, 2002
    Co-Authors: Elizabeth Adkins-regan
    Abstract:

    Zebra finches are group living socially monogamous birds that pair for life. Partner Preference is strongly sexually differentiated: males prefer to pair with females and females prefer to pair with males. Where do these Preferences come from? What occurs during development that produces adult birds that pair with the opposite sex? There is surprisingly little animal research that addresses such questions, especially in species that form pair-bonds. Our research program focuses on two processes that may be involved in the development of adult sexual-Partner Preference: (1) early (possibly organizational) hormone actions and (2) social experience. Females treated with estradiol or fadrozole (an estrogen synthesis inhibitor) as nestlings or embryos showed masculinized sexual-Partner Preference as adults, preferring to pair with other females even when potential male Partners were available. Removal of adult males from breeding cages, so that young birds were not exposed to males or to male–female pairs during development, eliminated sex-typical Partner Preferences; these birds were equally interested in both sexes and were more likely than controls to pair with a same-sex Partner. These experiments provide insights into the development of sexual-Partner Preference that may be applicable to other group living pair-bonding animals with biparental care. They also contribute to the foundation of animal research that is necessary for a biological approach to understanding the pair-bonding component of human sexual orientation.

  • Masculinized sexual Partner Preference in female zebra finches with sex-reversed gonads.
    Hormones and behavior, 2001
    Co-Authors: Elizabeth Adkins-regan, Juli Wade
    Abstract:

    Previous research in the zebra finch, a socially monogamous pair-bonding species, suggests that the Preference for opposite-sex Partners may arise in part through the organizing actions of sex steroids. To further investigate this process, zebra finch eggs were injected with 20 μg fadrozole, a potent estrogen synthesis inhibitor, or with the saline vehicle on embryonic day 5. As adults they were given two-choice sexual Partner Preference tests followed by group aviary tests. Fadrozole females had masculinized beak color and had testes or ovotestes instead of ovaries. Males were not affected by fadrozole; they did not differ from controls on any measure. In contrast, sexual Partner Preference was substantially masculinized in fadrozole females in the group aviary tests. Untreated males given a choice between fadrozole and untreated females preferred the untreated females, but this was equally the case when they were given a choice between saline-treated and untreated females. These results suggest that males do not specifically avoid females with testes and that male avoidance is unlikely to explain why fadrozole-treated females pair with other females. The present data add to the evidence that actions of gonadal steroids during development contribute to adult sex differences in Partner Preference in this pair-bonding species. Furthermore, because fadrozole-treated females do not produce audible song, the mechanisms regulating Partner Preference and song system development are dissociated.

  • Testosterone Increases Singing and Aggression But Not Male-Typical Sexual Partner Preference in Early Estrogen Treated Female Zebra Finches
    Hormones and behavior, 1999
    Co-Authors: Elizabeth Adkins-regan
    Abstract:

    Female zebra finches given estradiol benzoate (EB) as nestlings and testosterone propionate (TP) as adults show masculinized sexual Partner Preference, preferring females instead of males. This suggests an organizational effect of EB on sexual Partner Preference in a socially monogamous species that pairs for life. It is not known whether there is an activational hormone effect on sexual Partner Preference in this species, or whether adult testosterone treatment is necessary for masculinized Preference to be expressed. In this experiment females were injected with EB daily for the first 2 weeks posthatching. As adults they were given TP filled or empty implants. Subjects were then given two-choice Preference tests with male vs female stimuli, in which singing as well as proximity to the stimuli was recorded, followed by tests in a group aviary for social behavior and pairing Preference. Females with TP implants sang more than females with empty implants and were more aggressive toward other females. They did not, however, differ from females with empty implants in any measure of sexual Partner Preference. Neither group showed a marked Preference for males; instead both groups were equally interested in males and females. Thus adult testosterone treatment is not necessary for early estrogen treated females to show a shift in sexual Partner Preference in the male-typical direction.

Charles E. Roselli - One of the best experts on this subject based on the ideXlab platform.

  • Wired on steroids: sexual differentiation of the brain and its role in the expression of sexual Partner Preferences.
    Frontiers in endocrinology, 2011
    Co-Authors: Brenda M. Alexander, Donal C. Skinner, Charles E. Roselli
    Abstract:

    The Preference to seek out a sexual Partner of the opposite sex is robust and ensures reproduction and survival of the species. Development of female-directed Partner Preference in the male is dependent on exposure of the developing brain to gonadal steroids synthesized during critical periods of sexual differentiation of the central nervous system. In the absence of androgen exposure, a male-directed Partner Preference develops. The development and expression of sexual Partner Preference has been extensively studied in rat, ferret, and sheep model systems. From these models it is clear that gonadal testosterone, often through estrogenic metabolites, cause both masculinization and defeminization of behavior during critical periods of brain development. Changes in the steroid environment during these critical periods result in atypical sexual Partner Preference. In this manuscript, we review the major findings which support the hypothesis that the organizational actions of sex steroids are responsible for sexual differentiation of sexual Partner Preferences in select non-human species. We also explore how this information has helped to frame our understanding of the biological influences on human sexual orientation and gender identity.

  • Prenatal programming of sexual Partner Preference: the ram model.
    Journal of neuroendocrinology, 2009
    Co-Authors: Charles E. Roselli, Fred Stormshak
    Abstract:

    In our laboratory, the domestic ram is used as an experimental model to study the early programming of neural mechanisms underlying same-sex Partner Preference. This interest developed from the observation that approximately 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to oestrous ewes (female-oriented). One prominent feature of sexual differentiation in many species is the presence of a sexually dimorphic nucleus (SDN) in the preoptic/anterior hypothalamus that is larger in males than in females. Lesion studies in rats and ferrets implicate the SDN in the expression of sexual Preferences. We discovered an ovine SDN (oSDN) in the preoptic/anterior hypothalamus that is smaller in male- than in female-oriented rams and similar in size to the oSDN of ewes. Neurones of the oSDN show abundant aromatase expression that is also reduced in male-oriented compared to female-oriented rams. This observation suggests that sexual Partner Preferences are neurologically hard-wired and could be influenced by hormones. Aromatase-containing neurones constitute a nascent oSDN as early as day 60 of gestation, which becomes sexually dimorphic by day 135 of gestation when it is two-fold larger in males than in females. Exposure of fetal female lambs to exogenous testosterone from days 30-90 of gestation resulted in a masculinised oSDN. These data demonstrate that the oSDN develops prenatally and may influence adult sexual Preferences. Surprisingly, inhibition of aromatase activity in the brain of ram foetuses during the critical period did not interfere with defeminisation of adult sexual Partner Preference or oSDN volume. These results fail to support an essential role for neural aromatase in the sexual differentiation of sheep brain and behaviour. Thus, we propose that oSDN morphology and male-typical Partner Preferences may instead be programmed through an androgen receptor mechanism not involving aromatisation.

  • Sexual Partner Preference, hypothalamic morphology and aromatase in rams
    Physiology & behavior, 2004
    Co-Authors: Charles E. Roselli, Kay Larkin, Jessica M. Schrunk, Fredrick Stormshak
    Abstract:

    The male-oriented ram is a unique and valuable animal model for the study of hormonal, developmental and genetic contributions to sexual Partner Preference. Unlike most other mammalian models that are in use currently, variations in sexual attraction occur spontaneously in domestic ram populations. It is estimated that as many as 8-10% of rams exhibit a sexual Partner Preference for other males, classifying them as male-oriented rams. Studies have failed to identify any compelling social factors that can predict or explain the variations in sexual Partner Preferences of rams. Nor is there consensus on the endocrine and sensory responsiveness of male-oriented rams to other rams. However, a number of studies have reported differences in brain structure and function between male-oriented and female-oriented rams, suggesting that sexual Partner Preferences are neurologically hard-wired. Recently, we identified a sexually dimorphic nucleus (oSDN) in the sheep preoptic area-anterior hypothalamus. The oSDN is larger in female-oriented rams than in male-oriented rams and similar in size in male-oriented rams and ewes. In addition, mRNA levels for aromatase in the oSDN were higher in males than in females and were higher in female-oriented rams than in male-oriented rams. These results suggest a relationship between steroid hormones, specifically estrogens and oSDN morphology. In this review, we provide an overview of sexual behavior in rams and discuss the multiple factors that may contribute to the development and adult expression of same-sex Partner Preferences in rams.

  • Hormonal influences on sexual Partner Preference in rams.
    Archives of sexual behavior, 2002
    Co-Authors: Charles E. Roselli, John A. Resko, Fred Stormshak
    Abstract:

    Domestic rams display a naturally occurring variation in sexual Partner Preference, such that 6-10% of range-bred populations prefer male sexual Partners (male-oriented) in contrast to the majority of rams that prefer female sexual Partners (female-oriented). Male-oriented rams exhibit hormone profiles and stress responses distinctly different from their heterosexual counterparts. These differences include reduced circulating levels of testosterone that arise after anesthetization. Lower levels of aromatase activity in the medial preoptic area and estrogen receptor in the amygdala were also measured in male-oriented versus female-oriented rams and may represent an important link to sexual behavior that should be investigated. It is anticipated that the male-oriented ram model will be useful for studies aimed at identifying both the activational and organizational components and the neuronal substrates of male sexual Partner Preferences.

Karen L. Bales - One of the best experts on this subject based on the ideXlab platform.

  • revisiting paternal absence female alloparental replacement of fathers recovers Partner Preference formation in female but not male prairie voles microtus ochrogaster
    Developmental Psychobiology, 2020
    Co-Authors: Forrest Dylan Rogers, Karen L. Bales
    Abstract:

    In prairie voles (Microtus ochrogaster), biparental care of offspring is typical, and paternal absence in the pre-weaning development of offspring alters biobehavioral development. We sought to determine whether this altered development is due to the absence of specific paternal qualities or a general reduction in pup-directed care. We compared the biobehavioral development of pups reared under conditions of biparental (BPC), maternal-plus-alloparental (MPA; i.e., mother and older sister), and maternal only (MON) care. Older sisters provided a quantity of care equal to or greater than that of fathers. Growth rate and developmental milestones were unaffected by family composition, with the exception of earlier fur growth in MON conditions. In adulthood, we tested behaviors on an elevated plus maze, spontaneous alloparental care, and Partner Preference formation. We found no significant differences on the elevated plus maze and only marginal differences in alloparental care. While both female and male MON individuals showed deficits in Partner Preference formation, MPA females showed typical Partner Preference formation. However, the alloparental substitution of fathers was not sufficient for the typical development of Partner Preference formation in males. We conclude that paternal care plays a differentially important role in the social development of female and male prairie vole offspring.

  • early intranasal vasopressin administration impairs Partner Preference in adult male prairie voles microtus ochrogaster
    Frontiers in Endocrinology, 2017
    Co-Authors: Trenton C Simmons, Jessica F Balland, Janeet Dhauna, Sang Yun Yang, Jason L Traina, Jessica Vazquez, Karen L. Bales
    Abstract:

    Research supports a modulatory role for arginine vasopressin (AVP) in the expression of socially motivated behaviors in mammals. The acute effects of AVP administration are demonstrably prosocial across species, providing the justification for an ever-increasing measure of clinical interest over the last decade. Combining these results with noninvasive intranasal delivery results in an attractive system for offering intranasal AVP (IN-AVP) as a therapeutic for the social impairments of children with autism spectrum disorder. But, very little is known about the long-term effects of IN-AVP during early development. In this experiment, we explored whether a single week of early juvenile administration of IN-AVP (low = 0.05 IU/kg, medium = 0.5 IU/kg, high = 5.0 IU/kg) could impact behavior across life in prairie voles. We found increases in fecal boli production during open field and novel object recognition testing for the medium-dose in both males and females. Medium-dose females also had significantly more play bouts than control when exposed to novel conspecifics during the juvenile period. Following sexual maturity, the medium and high-doses of IN-AVP blocked Partner Preference formation in males, while no such impairment was found for any of the experimental groups in females. Finally, the high-dose selectively increased adult male aggression with novel conspecifics, but only after extended cohabitation with a mate. Our findings confirm that a single week of early IN-AVP treatment can have organizational effects on behavior across life in prairie voles. Specifically, the impairments in pair-bonding behavior experienced by male prairie voles should raise caution when the pro-social effects of acute IN-AVP demonstrated in other studies are extrapolated to long-term treatment.

  • Development of a Partner Preference test that differentiates between established pair bonds and other relationships in socially monogamous titi monkeys (Callicebus cupreus).
    American journal of primatology, 2015
    Co-Authors: Sarah B. Carp, Emily S. Rothwell, Alexis Bourdon, Sara M. Freeman, Emilio Ferrer, Karen L. Bales
    Abstract:

    Partner Preference, or the selective social Preference for a pair mate, is a key behavioral indicator of social monogamy. Standardized Partner Preference testing has been used extensively in rodents but a single test has not been standardized for primates. The goal of this study was to develop a Partner Preference test with socially monogamous titi monkeys (Callicebus cupreus) adapted from the widely used rodent test. In Experiment 1, we evaluated the test with pairs of titi monkeys (N = 12) in a three-chambered apparatus for 3 hr. The subject was placed in the middle chamber, with grated windows separating it from its Partner on one side and an opposite sex stranger on the other side. Subjects spent a greater proportion of time in proximity to their Partners' windows than the strangers', indicating a consistent Preference for the Partner over the stranger. Touching either window did not differ between Partners and strangers, suggesting it was not a reliable measure of Partner Preference. Subjects chose their Partner more than the stranger during catch and release sessions at the end of the test. In Experiment 2, we compared responses of females with current Partners (N = 12) in the Preference test with other relationship types representing former attachment bonds (N = 13) and no attachment bond (N = 8). Only females from established pair bonds spent significantly more time near their Partner's window compared to the stranger's indicating that this measure of Preference was unique to current Partners. Other measures of Preference did not differentiate behavior toward a current Partner and other relationship types. This test reproduces behavioral patterns found in previous studies in titi monkeys highlighting the accuracy of this new Partner Preference test. This test can be used as a standardized measure of Partner Preference in titi monkeys to quantitatively study pair bonding and evaluate factors influencing Partner Preference.

  • chronic intranasal oxytocin causes long term impairments in Partner Preference formation in male prairie voles
    Biological Psychiatry, 2013
    Co-Authors: Karen L. Bales, Allison M Perkeybile, Olivia G Conley, Meredith H Lee, Caleigh D Guoynes, Griffin M Downing, Catherine R Yun, Marjorie Solomon, Suma Jacob
    Abstract:

    Background Oxytocin (OT) is a hormone shown to be involved in social bonding in animal models. Intranasal OT is currently in clinical trials for use in disorders such as autism and schizophrenia. We examined long-term effects of intranasal OT given developmentally in the prairie vole ( Microtus ochrogaster ), a socially monogamous rodent, often used as an animal model to screen drugs that have therapeutic potential for social disorders. Methods We treated voles with one of three dosages of intranasal OT, or saline, from day 21 (weaning) through day 42 (sexual maturity). We examined both social behavior immediately following administration, as well as long-term changes in social and anxiety behavior after treatment ceased. Group sizes varied from 8 to 15 voles ( n = 89 voles total). Results Treatment with OT resulted in acute increases in social behavior in male voles with familiar Partners, as seen in humans. However, long-term developmental treatment with low doses of intranasal OT resulted in a deficit in Partner Preference behavior (a reduction of contact with a familiar opposite-sex Partner, used to index pair-bond formation) by male voles. Conclusions Long-term developmental treatment with OT may show results different to those predicted by short-term studies, as well as significant sex differences and dosage effects. Further animal study is crucial to determining safe and effective strategies for use of chronic intranasal OT, especially during development.

A. K. Slob - One of the best experts on this subject based on the ideXlab platform.

  • sexual differentiation of odor and Partner Preference in the rat
    Physiology & Behavior, 1996
    Co-Authors: Julie Bakker, J. Van Ophemert, A. K. Slob
    Abstract:

    Abstract Previous studies have shown that adult male rats, in which brain estrogen formation was inhibited neonatally by SC administration of the aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD), show an altered sexual Partner Preference. When tested in a three-compartment box, such gonadally intact ATD males approach and mate both with the estrous female and the sexually active male, whereas normal males prefer to approach and mate with the estrous female, avoiding the stimulus male. After castration in adulthood and estradiol treatment, ATD males prefer sexually active males. Similarly treated normal males prefer estrous females, and estrous females prefer to mate with males. In the present study, we asked what stimulus characteristics of active males vs. estrous females determined the different sexual Preferences of males, ATD males, and of females. Were they chemosensory cues or more distal cues such as actually seeing and hearing the stimulus animals or the reward of sexual activity with the stimulus animals? Sex differences in Preference were evident when animals were given a choice between soiled bedding from estrous females and from sexually active males. ATD and control males spent significantly more time on soiled bedding from estrous females than on soiled bedding from sexually active males. Control females spent significantly more time on soiled bedding from sexually active males than on soiled bedding from estrous females. More distal cues, such as seeing and hearing the stimulus animals, revealed differences in Preference between control males and females, but not between ATD and control males. Physical interaction with the stimulus animals was a prerequisite for revealing differences in Preference between ATD and control males. Then, the behavior of ATD males was clearly intermediate between that of normal male and female rats. In conclusion, neonatal estradiol is important for the psychosexual development of the male rat. However, the present data suggest that the psychosexual development of the male rat also requires either prenatal estradiol or perinatal testosterone.

  • sdn poa volume sexual behavior and Partner Preference of male rats affected by perinatal treatment with atd
    Physiology & Behavior, 1994
    Co-Authors: E.j. Houtsmuller, T. Brand, F H De Jonge, R N J M A Joosten, N E Van De Poll, A. K. Slob
    Abstract:

    The present study investigated 1) the importance of the aromatization process during the perinatal period for the development of the sexually dimorphic nucleus in the preoptic area of the hypothalamus (SDN-POA) of male rats, and 2) the relationship between SDN-POA volume and parameters of masculinization in male rats that were treated perinatally with the aromatase-inhibitor ATD. Males were treated with ATD either prenatally or pre- and neonatally, or with the vehicle. Masculine sexual behavior and Partner Preference were investigated in adulthood. Thereafter, animals were sacrificed and SDN-POA volume was measured. The SDN-POA volume was reduced in both the prenatally and the pre- and neonatally treated group, with a larger reduction in the latter than in the former group. Combined pre- and neonatal ATD treatment resulted in reduced frequency of mounts, intromissions, and ejaculations, as well as a reduced Preference for a female over a male. The SDN-POA size was significantly and positively correlated with frequency of masculine sexual behavior, as well as Preference for a female over a male.

  • A semiautomated test apparatus for studying Partner Preference behavior in the rat
    Physiology & behavior, 1994
    Co-Authors: Julie Bakker, J. Van Ophemert, F. Eijskoot, A. K. Slob
    Abstract:

    A semiautomated three-compartment box (3CB) for studying Partner Preference behavior of rats is decribed. This apparatus automatically records the rat's time spent in each compartment, as well as the locomotor activity (i.e., the number of visits an animal pays to each compartment). Software was developed for calculating Partner Preference scores. Behavioral testing in the semiautomated 3CB, which is a modification of an earlier version, is less time consuming and less laborious. Three 3CBs can be observed simultaneously by two trained observers, and the behavioral interactions of three experimental animals with the stimulus animals can be observed and scored by hand. The use of the new apparatus was validated by studying adult Partner Preference behavior of neonatally ATD-treated male rats. The collected data fully corroborate previous results, obtained in the earlier version of the 3CB, again revealing the behavioral bisexual nature of these ATD males. A new finding was the much higher locomotor activity of the ATD males compared to controls.

  • organization of Partner Preference and sexual behavior and its nocturnal rhythmicity in male rats
    Behavioral Neuroscience, 1993
    Co-Authors: Julie Bakker, J. Van Ophemert, A. K. Slob
    Abstract:

    Male rats were neonatally treated with 1,4,6-androstatriene-3,17-dione (ATD), which blocks aromatization of testosterone (T) to estradiol (E2), from Days 0, 2, or 5 through 14. Adult Partner Preference behavior (PPB; choice between estrous female rat [F] and active male rat [M]) was studied in the early part of the dark phase of the light-dark (LD) cycle. ATD Day 0 Ms showed a Preference for the stimulus M or showed no Preference for either of the stimulus Ss. Controls preferred the estrous F. ATD Days 2 and 5 Ms showed PPB intermediate between ATD Day 0 Ms and controls. Thus the neonatally sensitive period for organization of adult PPB extends beyond Day 5. Furthermore, PPB showed a nocturnal rhythmicity in ATD Ms but not in controls. In the late part of the dark phase, all Ms showed a Preference for the stimulus F. ATD Days 2 and 5 Ms and control Ms were no longer different in PPB, but ATD Day 0 Ms still showed significantly lower Preference scores for F than all other Ms. Thus the E2 metabolite of T suppresses organization of an adult nocturnal rhythm in PPB.

  • hormonal regulation of adult Partner Preference behavior in neonatally atd treated male rats
    Behavioral Neuroscience, 1993
    Co-Authors: Julie Bakker, T. Brand, J. Van Ophemert, A. K. Slob
    Abstract:

    Male rats, neonatally treated with ATD (1,4,6-androstatriene-3,17-dione), which blocks the aromatization of testosterone into estradiol (E2), were tested for adult Partner Preference behavior (PPB; estrous female vs. active male). Castration caused a decrease in Preference for the female Partner in all males, with ATD males showing lower Preference for the female Partner than controls. Long-term castrated males did not show Preference for either Partner. Precastration levels of PPB in control males occurred after treatment with E2 or dihydrotestosterone (DHT) plus E2. DHT alone had no effect on PPB. With E2 alone, the ATD males clearly preferred the male Partner. When DHT was added, these ATD males showed no Preference for either Partner or a low Preference for the female Partner. In conclusion, adult PPB in male rats is activated by endogenous testosterone or by both its metabolites (DHT and E2) or by E2 alone. ATD males showed a much lower Preference for the female. There was a differential effect of DHT and E2: DHT had no effect, but E2 clearly caused ATD males to prefer the male Partner and control males to prefer the female Partner.