References of "Hormones & Behavior"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailEffects of social experience on subsequent sexual performance in naïve male Japanese quail (Coturnix japonica)
Cornil, Charlotte ULg; Ball, Gregory

in Hormones & Behavior (2010), 57

On their first sexual encounter, naïve male Japanese quail will attend to and approach a female; they sometimes mount but they do not always copulate. During the second encounter, most males successfully ... [more ▼]

On their first sexual encounter, naïve male Japanese quail will attend to and approach a female; they sometimes mount but they do not always copulate. During the second encounter, most males successfully copulate. Although sexual experience facilitates subsequent sexual interactions, sensory cues provided by females, independent of any sexual encounter, may also enhance sexual performance. To investigate whether previous exposure to a conspecific affects subsequent sexual behavior, we allowed inexperienced males to observe an empty box, or a conspecific consisting of either an experienced female or male for 2.5 min/day on 7 days. Measures of appetitive sexual behavior were recorded during these tests. On day 8, subjects were allowed to copulate with a novel female for 5 min. On the following days, all subjects were repeatedly provided with visual access to a female and allowed to mate. In the pre-copulatory trials males initially exhibited a high frequency of appetitive responses that dissipated with repetition. Pre-copulatory experience also significantly affected motivation to mate with subjects exposed to females copulating more quickly than other subjects. Post-copulatory appetitive behavior also differed between groups: control subjects showed the highest behavioral frequency followed by males exposed to females and finally males exposed to males. These data indicate that pre-copulatory social experience profoundly influences subsequent sexual behavior and probably reproductive success. This experience effect is independent of any hormonal effect (such as one resulting from changes in secretion following different social interactions) given that the subjects were castrates chronically treated with testosterone. [less ▲]

Detailed reference viewed: 23 (4 ULg)
Full Text
Peer Reviewed
See detailThe alpha-fetoprotein knock-out mouse model suggests that parental behavior is sexually differentiated under the influence of prenatal estradiol.
Keller, Matthieu; Pawluski, Jodi ULg; Brock, Olivier ULg et al

in Hormones & Behavior (2010)

In rodent species, sexual differentiation of the brain for many reproductive processes depends largely on estradiol. This was recently confirmed again by using the α-fetoprotein knockout (AFP-KO) mouse ... [more ▼]

In rodent species, sexual differentiation of the brain for many reproductive processes depends largely on estradiol. This was recently confirmed again by using the α-fetoprotein knockout (AFP-KO) mouse model, which lacks the protective actions of α-fetoprotein against maternal estradiol and as a result represents a good model to determine the contribution of prenatal estradiol to the sexual differentiation of the brain and behavior. In the present study, we determined whether parental responses are differentiated prenatally under the influence of estradiol. It was found that AFP-KO females showed longer latencies to retrieve pups to the nest and also exhibited lower levels of crouching over the pups in the nest in comparison to WT females. Thus our results suggest that prenatal estradiol defeminizes the parental brain in mice. [less ▲]

Detailed reference viewed: 25 (5 ULg)
Full Text
Peer Reviewed
See detailComplex modulation of singing behavior by testosterone in an open-ended learner, the European Starling.
Van Hout, Alain J*-M; Eens, Marcel; Balthazart, Jacques ULg et al

in Hormones & Behavior (2009), 56(5), 564-73

In many temperate zone songbird species males only produce song during the breeding season, when plasma testosterone (T) levels are high. Males of some species sing throughout the year, even when T levels ... [more ▼]

In many temperate zone songbird species males only produce song during the breeding season, when plasma testosterone (T) levels are high. Males of some species sing throughout the year, even when T levels are low, indicating a dissociation between high T levels and song rate. Given that few studies have taken advantage of these species, we compare here song traits expressed under high versus low T concentrations and we study the role of testosterone in adult song learning in the European Starling, an open-ended learner in which repertoire size dramatically increases with age. We performed a detailed comparison of song complexity and song rate between fall and spring in 6-year-old intact male European starlings. In parallel, we investigated whether potential seasonal changes were regulated by the gonadally induced increase in plasma T, by comparing seasonal changes in intact and castrated males of the same age (castrated as juveniles during their first fall) and by subsequently experimentally elevating T in half of the castrated males. While song rate and stereotypy did not differ between intacts and castrates or between fall and spring, both groups increased their average song bout length from fall to spring, but only intact males increased their repertoire size, indicating that effects of seasonal T changes differ between song traits. Intact males overall displayed a larger song repertoire and a longer bout length than the castrates, and implantation with T caused a turnover in repertoire composition in castrates. However, as the castrates had never experienced high T levels and yet displayed a markedly higher repertoire size than that of typical yearling males, this suggests that the progressive increase of song repertoire with age in male starlings is not dependent on gonadal T, although it may be T-enhanced. [less ▲]

Detailed reference viewed: 43 (1 ULg)
Full Text
Peer Reviewed
See detailEffects of aggressive encounters on plasma corticosteroid-binding globulin and its ligands in white-crowned sparrows.
Charlier, Thierry ULg; Underhill, Caroline; Hammond, Geoffrey L. et al

in Hormones & Behavior (2009), 56(3), 339-47

In birds, corticosteroid-binding globulin (CBG) binds corticosterone, progesterone and testosterone. The concentration of each ligand can alter the binding of the other ligands through competitive ... [more ▼]

In birds, corticosteroid-binding globulin (CBG) binds corticosterone, progesterone and testosterone. The concentration of each ligand can alter the binding of the other ligands through competitive interactions. Thus, an increase in corticosterone or progesterone may displace testosterone bound to CBG, leading to an increase in bioactive free testosterone levels without affecting total testosterone levels in the circulation. Aggressive interactions increase plasma total testosterone levels in some birds but not in others. Here, we tested the hypothesis that aggressive encounters in the late breeding season would not increase total testosterone levels in plasma, but would alter CBG, total corticosterone or total progesterone levels in such a way as to modify the number of available binding sites and therefore occupancy by testosterone. A marked decrease in CBG occupancy by testosterone would indirectly suggest an increase in free testosterone levels in plasma. Wild male white-crowned sparrows were exposed to a simulated territorial intrusion (STI) or control for 30 min. Subjects were then caught and bled. We measured CBG using a ligand-binding assay and corticosterone, progesterone and testosterone using highly sensitive radioimmunoassays. STI significantly increased aggressive behaviors but did not affect plasma total testosterone levels. STI significantly increased plasma CBG and total corticosterone levels and decreased plasma total progesterone levels. We predict that CBG occupancy by corticosterone will increase slightly following an aggressive encounter. However, this small change is unlikely to increase free testosterone levels, because of the large number of seemingly unoccupied CBG binding sites in these subjects. [less ▲]

Detailed reference viewed: 21 (6 ULg)
Full Text
Peer Reviewed
See detailRapid action on neuroplasticity precedes behavioral activation by testosterone.
Charlier, Thierry ULg; Ball, Gregory F; Balthazart, Jacques ULg

in Hormones & Behavior (2008), 54(4), 488-95

Testosterone has been shown to increase the volume of steroid-sensitive brain nuclei in adulthood in several vertebrate species. In male Japanese quail the volume of the male-biased sexually dimorphic ... [more ▼]

Testosterone has been shown to increase the volume of steroid-sensitive brain nuclei in adulthood in several vertebrate species. In male Japanese quail the volume of the male-biased sexually dimorphic medial preoptic nucleus (POM), a key brain area for the control of male sexual behavior, is markedly increased by testosterone. Previous studies assessed this effect after a period of 8-14 days but the exact time course of these effects is unknown. We asked here whether testosterone-dependent POM plasticity could be observed at shorter latencies. Brains from castrated male quail were collected after 1, 2, 7 and 14 days of T treatment (CX+T) and compared to brains of untreated castrates (CX) collected after 1 or 14 days. POM volumes defined either by Nissl staining or by aromatase immunohistochemistry increased in a time-dependent fashion in CX+T subjects and almost doubled after 14 days of treatment with testosterone while no change was observed in CX birds. A significant increase in the average POM volume was detected after only one day of testosterone treatment. The optical density of Nissl and aromatase staining was also increased after one or two days of testosterone treatment. Activation of male copulatory behavior followed these morphological changes with a latency of approximately one day. This rapid neurochemical and neuroanatomical plasticity observed in the quail POM thus seems to limit the activation of male sexual behavior and offers an excellent model to analyze features of steroid-regulated brain structure and function that determine behavior expression. [less ▲]

Detailed reference viewed: 38 (3 ULg)
Full Text
Peer Reviewed
See detailSimultaneous pituitary-gonadal recrudescence in two Corsican populations of male blue tits with asynchronous breeding dates
Caro, S. P.; Lambrechts, M. M.; Chastel, O. et al

in Hormones & Behavior (2006), 50(3), 347-360

Animal populations living in geographically variable environments respond to different selection pressures. The adaptive character of the responses to environmental information determines the degree of ... [more ▼]

Animal populations living in geographically variable environments respond to different selection pressures. The adaptive character of the responses to environmental information determines the degree of synchrony of the breeding period with local optimal conditions. An example is provided by two populations of Mediterranean blue tits (Parus caeruleus) in Corsica, breeding in different habitats, with a 1-month difference in the onset of egg laying. This difference in the onset of lay is supposed to be adaptive because, although chicks from both populations are raised mostly on caterpillars, the timing of the appearance of caterpillars is earlier for populations of tits associated with deciduous oak trees than those associated with evergreen oak trees. Here, we show that, despite the difference in the timing of egg laying, males from these two populations start seasonal hypothalamo-hypophysial-testicular development at approximately the same time, in late winter. Specifically, the vernal recrudescence of brain GnRH-I perikarya and fibers, testes volume and song activity began around the same dates and proceeded at the same pace in late winter in both populations. Plasma testosterone and LH levels displayed seasonal variations that were shifted by less than 2 weeks compared to the 1-month difference in egg laying periods. We hypothesize that the strong selection pressures on these two populations to adapt the timing of their breeding seasons to their local environment may have acted mostly on the female egg laying dates, and not so much on the initiation and rate of seasonal recrudescence of the hypothalamo-hypophysial-testicular activity in males. (c) 2006 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 31 (0 ULg)
Full Text
Peer Reviewed
See detailEnhanced urinary odor discrimination in female aromatase knockout (ArKO) mice
Wesson, D. W.; Keller, Matthieu ULg; Douhard, Quentin ULg et al

in Hormones & Behavior (2006), 49(5), 580-586

We asked whether odor discrimination abilities are sexually dimorphic in mice and, if so, whether the perinatal actions of estradiol contribute to these sex differences. The ability to discriminate ... [more ▼]

We asked whether odor discrimination abilities are sexually dimorphic in mice and, if so, whether the perinatal actions of estradiol contribute to these sex differences. The ability to discriminate different types of urinary odors was compared in male and female wild-type (WT) subjects and in mice with a hornozygous-null mutation of the estrogen synthetic enzyme, aromatase (aromatase knockout; ArKO). Olfactory discrimination was assessed in WT and ArKO male and female mice after they were gonadectomized in adulthood and subsequently treated with estradiol benzoate. A liquid olfactometer was used to assess food-motivated olfactory discrimination capacity. All animals eventually learned to distinguish between urinary odors collected from gonadally intact males and estrous females; however, WT males as well as ArKO mice of both sexes learned this discrimination significantly more rapidly than WT females. Similar group differences were obtained when mice discriminated between urinary odors collected from gonadally intact vs. castrated males or between two non-social odorants, amyl and butyl acetate. When subjects had to discriminate volatile urinary odors from ovariectomized female mice treated with estradiol sequenced with progesterone versus estradiol alone, ArKO females quickly acquired the task whereas WT males and females as well as ArKO males failed to do so. These results demonstrated a strong sex dimorphism in olfactory discrimination ability, with WT males performing better than females. Furthermore, female ArKO mice showed an enhanced ability to discriminate very similar utinary odorants, perhaps due to an increased sensitivity of the main olfactory nervous system to adult estradiol treatment as a result perinatal estrogen deprivation. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 23 (0 ULg)
Full Text
Peer Reviewed
See detailAndrogen metabolism and the activation of male sexual behavior: It's more complicated than you think!
Ball, G. F.; Balthazart, Jacques ULg

in Hormones & Behavior (2006), 49(1), 1-3

Detailed reference viewed: 12 (0 ULg)
Full Text
Peer Reviewed
See detailAttraction thresholds and sex discrimination of urinary odorants in male and female aromatase knockout (ArKO) mice
Pierman, S.; Douhard, Quentin ULg; Balthazart, Jacques ULg et al

in Hormones & Behavior (2006), 49(1), 96-104

We previously found that both male and female aromatase knockout (ArKO) mice, which cannot synthesize estrogens due to a targeted mutation of the aromatase gene, showed less investigation of volatile body ... [more ▼]

We previously found that both male and female aromatase knockout (ArKO) mice, which cannot synthesize estrogens due to a targeted mutation of the aromatase gene, showed less investigation of volatile body odors from anesthetized conspecifics of both sexes in Y-maze tests. We now ask whether ArKO mice are in fact capable of discriminating between and/or responding to volatile odors. Using habituation/dishabituation tests, we found that gonadectomized ArKO and wild-type (WT) mice of both sexes, which were tested without any sex hormone replacement, reliably distinguished between undiluted volatile urinary odors of either adult males or estrous females versus deionized water as well as between these two urinary odors themselves. However, ArKO mice of both sexes were less motivated than WT controls to investigate same-sex odors when they were presented last in the sequence of stimuli. In a second experiment, we compared the ability of ArKO and WT mice to respond to decreasing concentrations of either male or female urinary odors. We found a clear-cut sex difference in urinary odor attraction thresholds among WT mice: WT males failed to respond to urine dilutions higher than 1:20 by volume, whereas WT females continued to respond to urine dilutions up to 1:80. Male ArKO mice resembled WT females in their ability to respond to lower concentrations of urinary odors, raising the possibility that the observed sex difference among WT mice in urine attraction thresholds results from the perinatal actions of estrogen in the male nervous system. Female ArKO mice failed to show significant dishabituation responses to two (1:20 and 1:80) dilutions of female urine, perhaps, again, because of a reduced motivation to investigate less salient, same-sex urinary odors. Previously observed deficits in the preference of ArKO male and female mice to approach volatile body odors from conspecifics of either sex cannot be attributed to an inability of ArKO subjects to discriminate these odors according to sex but instead may reflect a deficient motivation to approach same-sex odors, especially when their concentration is low. [less ▲]

Detailed reference viewed: 69 (1 ULg)
Full Text
Peer Reviewed
See detailRapid effects of aromatase inhibition on male reproductive behaviors in Japanese quail
Cornil, Charlotte ULg; Taziaux, Mélanie ULg; Baillien, M. et al

in Hormones & Behavior (2006), 49(1), 45-67

Non-genomic effects of steroid hormones on cell physiology have been reported in the brain. However, relatively little is known about the behavioral significance of these actions. Male sexual behavior is ... [more ▼]

Non-genomic effects of steroid hormones on cell physiology have been reported in the brain. However, relatively little is known about the behavioral significance of these actions. Male sexual behavior is activated by testosterone partly through its conversion to estradiol via the enzyme aromatase in the preoptic area (POA). Brain aromatase activity (AA) changes rapidly which might in turn be important for the rapid regulation of behavior. Here, acute effects of Vorozole (TM), an aromatase inhibitor, injected IP at different doses and times before testing (between 15 and 60 min), were assessed on male sexual behavior in quail. To limit the risk of committing both types of statistical errors (I and II), data of all experiments were entered into a meta-analysis. Vorozole (TM) significantly inhibited mount attempts (P < 0.05, size effect [g] = 0.527) and increased the latency to first copulation (P < 0.05, g = 0.251). The treatment had no effect on the other measures of copulatory behavior. Vorozole (TM) also inhibited appetitive sexual behavior measured by the social proximity response (P < 0.05, g = 0.534) or rhythmic cloacal sphincter movements (P < 0.001, g = 0.408). Behavioral inhibitions always reached a maximum at 30 min. Another aromatase inhibitor, androstatrienedione, induced a similar rapid inhibition of sphincter movements. Radioenzyme assays demonstrated that within 30 min Vorozole (TM) had reached the POA and completely blocked AA measured in homogenates. When added to the extracellular milieu, Vorozole (TM) also blocked within 5 min the AA in POA explants maintained in vitro. Together, these data demonstrate that aromatase inhibition rapidly decreases both consummatory and appetitive aspects of male sexual behavior. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 17 (3 ULg)
Full Text
Peer Reviewed
See detailAlpha-fetoprotein (AFP) knock out mice demonstrate the protective role of AFP during brain sexual differentiation
Bakker, Julie ULg; de Mees, C.; Balthazart, Jacques ULg et al

in Hormones & Behavior (2005, June), 48(1), 87

Detailed reference viewed: 25 (1 ULg)
Full Text
Peer Reviewed
See detailDaily changes in the expression of the steroid receptor coactivator SRC-1
Charlier, T. D.; Ball, G. F.; Balthazart, Jacques ULg

in Hormones & Behavior (2005, June), 48(1), 93

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
See detailDifferences in neural activation following expression of appetitive and consummatory male sexual behavior in the quail brain
Taziaux, Mélanie ULg; Cornil, Charlotte ULg; Dejace, C. et al

in Hormones & Behavior (2005, June), 48(1), 130

Detailed reference viewed: 15 (4 ULg)
Full Text
Peer Reviewed
See detailDistribution of Reelin and its cytoplasmic signaling protein, DAB-1 in the forebrain of male canaries
Boseret, Géraldine ULg; Ball, G. F.; Balthazart, Jacques ULg

in Hormones & Behavior (2005, June), 48(1), 90

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailTestosterone-induced singing is regulated by social status in male canaries (serinus canaria)
Carere, C.; Boseret, Géraldine ULg; Ball, G. F. et al

in Hormones & Behavior (2005, June), 48(1), 92

Detailed reference viewed: 15 (3 ULg)
Full Text
Peer Reviewed
See detailCoordinated and dissociated effects of testosterone on singing behavior and song control nuclei in canaries (Serinus canaria)
Sartor, Jennifer J.; Balthazart, Jacques ULg; Ball, Gregory F.

in Hormones & Behavior (2005), 47(4), 467-476

Temperate zone songbirds that breed seasonally exhibit pronounced differences in reproductive behaviors including song inside and outside the breeding season. Springlike long daylengths are associated ... [more ▼]

Temperate zone songbirds that breed seasonally exhibit pronounced differences in reproductive behaviors including song inside and outside the breeding season. Springlike long daylengths are associated with increases in plasma testosterone (T) concentrations, as well as with increases in singing and in the volume of several brain nuclei known to control this behavior. The mechanisms whereby T can induce changes in behavior and brain, and whether or not these effects are differentially regulated, have recently begun to be examined, as has the question of the relative contributions of T and its androgenic and estrogenic metabolites to the regulation of this seasonal behavioral and neural plasticity. In this experiment, we examined the effects of T, 5 alpha-dihydrotestosterone, or 17 beta-estradiol treatment on castrated male canaries housed on short days and compared neural and behavioral effects in these males to similarly-housed males given only blank implants. We observed that only T treatment was effective in eliciting significant increases in singing behavior after 11 days of hormone exposure. In addition, T alone was effective in increasing the volume of a key song production nucleus, HVC. However, at this time, none of the steroids had any effects on the volumes of two other song control nuclei, Area X of the medial striatum and the robust nucleus of the arcopallium (RA), that are efferent targets of HVC, known to be regulated by androgen in canaries and also to play a role in the control of adult song. T can thus enhance singing well before concomitant androgen-induced changes in the song control system are complete. (c) 2004 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 25 (0 ULg)
Full Text
See detailDaily changes in the expression of the steroid receptor coactivator SRC-1.
Charlier, Thierry ULg; Ball, Gregory F.; Balthazart, Jacques ULg

in Hormones & Behavior (2005), 48

Steroid receptor coactivators such as SRC-1 significantly modulate the expression of steroid-dependent physiological and behavioral characteristics in birds and mammals. Changes in coactivator protein ... [more ▼]

Steroid receptor coactivators such as SRC-1 significantly modulate the expression of steroid-dependent physiological and behavioral characteristics in birds and mammals. Changes in coactivator protein expression are therefore likely to affect receptor-mediated transcriptional activity. We previously reported a tissue-dependent regulation of SRC-1 mRNA and protein levels by sex, stress and testosterone in the quail brain. In addition, SRC-1 expression has been shown to vary in mammals during development or in adulthood as a function of seasonal variation in photoperiod. We describe here tissue-specific changes of SRC-1 expression over the course of the day in quail. SRC-1 protein quantified by Western blots in the hindbrain gradually increased in the morning, reached a peak around midday and declined significantly in the afternoon. In contrast, SRC-1 protein levels in the optic lobes progressively decreased in the morning to reach their lowest values around midday before rising in the afternoon. The coactivator concentration in the hippocampus exhibited a progressive increase throughout the day. No change in the SRC-1 protein was detected during the day in the preoptic area and in the cerebellum. The functional significance and the mechanisms of regulation underlying such changes remain to be understood. An important unresolved question is whether this diurnal variation in SRC-1 expression is circadian in nature and if so if SRC-1 is an active player linked to clock genes in the generation of circadian rhythms or if the observed changes in SRC-1 expression are a consequence of the rhythms generated by these genes. [less ▲]

Detailed reference viewed: 11 (5 ULg)
Full Text
Peer Reviewed
See detailEstrogen-deficient female but not male aromatase knockout (ArKO) mice exhibit "depressive-like" symptoms
Bakker, Julie ULg; Dalla, C.; Antoniou, K. et al

in Hormones & Behavior (2004, June), 46(1), 127

Detailed reference viewed: 15 (2 ULg)