The Effects of Apomorphine on Sexual Behavior and Aggression in Male Golden Hamsters

The general dopamine agonist apomorphine has been shown to have mostly facilitative effects on sexual behavior in rodents (Domingues & Hull, 2005; Bitran & Hull, 1987). A study looking at the effectsof apomorphine on sexual behavior in male golden hamsters observed that after systemic injections of apomorphine the males became aggressive towards the estrous females (Floody, unpublished). Studies on aggressive behavior have shown that apomorphine has facilitative effects on aggression in rodents (Nelson & Trainor, 2007; van Erp & Miczek, 2000; Ferrari, van Erp, Tornatzky, & Miczek, 2003). The studies presented here attempt to unravel the effects that apomorphine has on sexual and aggressive behavior in male golden hamsters. Studies 1, 2, 3, and 4 focused on the effects of apomorphine on aggression and Study 5 focused on the effects of apomorphine on sexual behavior. It was important for the purposes ofthis study to have separate, specific measures of aggression and sexual behavior that did not involve a social context that would involve multiple behaviors and motivations. The measure used to assessaggression was flank marking behavior. The measure used to assess sexual behavior was the number of vocalizations in response to sexual stimuli. The results from Studies 1, 2, and 3 suggested thatapomorphine increased aggressive motivation in a dose-dependent manner. In Studies 1 and 2 there was a high occurrence of stereotyped cheek pouching that interfered with the flank marking behavior. In Study 3 the procedure was modified to prevent cheek pouching and flank marking was observed uninhibited. Study 5 suggested a decrease in vocalizations after apomorphine treatment. However, this decrease may have been a result of the increase in stereotyped licking behavior. Results suggested that systemic apomorphine treatments increase aggressive motivation in hamsters. The increase in aggressive motivation may confuse the perception of the sensory signals that the males receive from the estrous females. They may haveperceived the estrous female as a nonestrous female which they would normally associate with an aggressive interaction (Lehman, Powers, & Winans, 1983).

Role of Acetylcholine in Control of Sexual Behavior of Male and Female Mammals

The results of studies using systemic or central applications of cholinergic drugs suggest that acetylcholine makes important contributions to the neurochemical control of male- and female-typical reproductive behaviors. In males, cholinergic control seems largely specific to some elements or aspects of copulatory behavior that can vary significantly across species. Synapses in or near the medial preoptic area represent part of this mechanism, but the entire system appears to extend more widely, perhaps especially to one or more structures flanking some part of the lateral ventricle. In females, the lordosis response that essentially defines sexual receptivity is clearly responsive to cholinergic drugs. The same seems likely to be true of other elements of female sexual behavior, but additional studies will be needed to confirm this. Changes in cholinergic activity may help to mediate estrogenic effects on female sexual behavior. However, estrogen exposure can increase or decrease cholinergic effects, suggesting a relationship that is complex and requires further analysis. Also presently unclear is the localization of the cholinergic effects on female sexual responses. Though periventricular sites again have been implicated, their identity is presently unknown. This review discusses these and other aspects of the central cholinergic systems affecting male and female sexual behaviors. Copyright 2014 Elsevier Inc. All rights reserved.

The quantitative genetic basis of offspring solicitation and parental response in a passerine bird with biparental care

The coevolution of parental investment and offspring solicitation is driven by partly different evolutionary interests of genes expressed in parents and their offspring. In species with biparental care, the outcome of this conflict ma!: be influenced by the sexual conflict over parental investment, Models for the resolution of such family conflicts have made so far untested assumptions about genetic variation and covariation in the parental resource provisioning response and the level of offspring solicitation. Using a combination of cross-fostering and begging playback experiments, we show that, in the great tit (Parus major), (i) the begging call intensity of nestlings depends on their common origin, suggesting genetic variation for this begging display, (ii) only mothers respond to begging calls by increased food provisioning, and (iii! the size of the parental response is positively related to the begging call intensity of nestlings in the maternal but not paternal line. This study indicates that genetic covariation, its differential expression in the maternal and paternal lines and/or early environmental and parental effects need to be taken into account when predicting the phenotypic outcome of the conflict over investment between genes expressed in each parent and the offspring. [References: 36]

Gaze behavior nonlinear dynamics assessed in virtual immersion as a diagnostic index of sexual deviancy: preliminary results

This paper presents preliminary results about the use of virtual characters, penile plethysmography and gaze behaviour dynamics to assess deviant sexual preferences. Pedophile patients’ responses are compared to those of non-deviant subjects while they were immersed with virtual characters depicting relevant sexual features.

Explosive speciation rates and unusual species richness in haplochromine cichlid fishes: Effects of sexual selection

Ancient lakes are often unusually species rich, mostly as a result of radiation and species-flock formation having taken place in only one or a few of many taxa present. Understanding why some taxa radiate and others do not is at the heart of understanding biodiversity. In this chapter I discuss possible explanations for disproportionally large species numbers in some cichlid fish lineages in East African Great Lakes: the halochromine cichlid fishes in Lakes Victoria and Malawi. I show that speciation rates in this group are higher than in any other lacustrine fish radiation. Against this background, I review hypotheses put forward to explain diversity in cichlid species flocks. The evolution of species diversity requires three processes: speciation, ecological radiation and anatomical diversification, and it is wrong to consider hypotheses that are relevant to different processes as alternatives to each other. The African cichlid species flocks show unusually high ecological species packing in several phylogenetic groups and unusually high speciation rates in haplochromines. Therefore, it maybe concluded that at least two evolutionary models are required to explain the difference between cichlid diversity and other fish diversity in East African Lakes: one for speciation in haplochromines and one for coexistence. Subsequently I review work on speciation in haplochromines, and in particular studies aimed at testing the hypothesis of speciation by sexual selection. Haplochromines have a polygynous mating system, conducive to sexual selection, but other polygynous cichlids are not particularly species rich. This suggests that more than just strong sexual selection is required to explain haplochromine species richness. Recent palaeoecological evidence undermines the previously popular hypotheses that explained the species richness of Lake Victoria in terms of speciation under varying natural or sexual selection regimes in satellite lakes or in isolated lake basins. I summarize experimental and comparative studies, which provide evidence for two mechanisms of sympatric speciation by disruptive sexual selection on polymorphic coloration. Such modes of speciation may explain (i) the high speciation rates in colour polymorphic lineages of haplochromine cichlids under conditions where colour variation is visible in clear water, and (ii) in combination with factors that affect population survival, the unusual species richness in haplochromine species flocks. I argue that sexual selection, if disruptive, can accelerate the pace of adaptive radiation because the resultant genetic population fragmentation allows a much increased rate of differential response to disruptive natural selection. Hence, the ecological pattern of diversity resembles that produced by disruptive natural selection, with the difference that disruptive sexual selection continues to cause (gross) speciation even after niche space is saturated. This may explain the unusually high numbers of very closely related and ecologically similar species in haplochromine species flocks. The role of disruptive sexual selection is twofold: it not only causes speciation, but also maintains reproductive isolation in sympatry between species that have evolved in sympatry or allopatry. Therefore, the maintenance of diversity in species flocks that originated through sexual selection depends on the persistence of the selection regime within the environmental signal space under which that diversity evolved.

Sexual harassment over the telephone: Occupational risk at call centers

The phenomenon of sexually harassing telephone calls in the workplace has been studied only marginally. In the present study 106 employees working in call centres in Germany answered a questionnaire regarding their experiences of sexual harassment over the telephone. The following data are presented: description of the phenomenon, i.e. prevalence and characteristics, stress reactions of the victims, behavioural reactions and coping strategies, consequences and anticipated consequences; prediction of the stress reactions by characteristics of the situation; and employees' recommendations for coping with sexually harassing calls. It was found that the female employees were more often sexually harassed over the telephone at work than their male colleagues. Three out of four female employees had experienced sexually harassing telephone calls; in the majority of cases the harassers were men. Characteristic patterns of harassment included groaning, sexual insults, silence, and threats of sexual violence. Some 16% of the harassed female employees described these experiences as extremely stressful. If the harassment contained threats of sexual violence and groaning, the perceived physical response was stronger. Being subjected to sexual harassment over the telephone both at home and at work was a more severe stress than having the experience only in the workplace. In conclusion, employees' recommendations for coping with the occurrence of sexually harassing calls are described.

Potential Impact of Sexual Transmission on Ebola Virus Epidemiology: Sierra Leone as a Case Study.

BACKGROUND Sexual transmission of Ebola virus disease (EVD) 6 months after onset of symptoms has been recently documented, and Ebola virus RNA has been detected in semen of survivors up to 9 months after onset of symptoms. As countries affected by the 2013-2015 epidemic in West Africa, by far the largest to date, are declared free of Ebola virus disease (EVD), it remains unclear what threat is posed by rare sexual transmission events that could arise from survivors. METHODOLOGY/PRINCIPAL FINDINGS We devised a compartmental mathematical model that includes sexual transmission from convalescent survivors: a SEICR (susceptible-exposed-infectious-convalescent-recovered) transmission model. We fitted the model to weekly incidence of EVD cases from the 2014-2015 epidemic in Sierra Leone. Sensitivity analyses and Monte Carlo simulations showed that a 0.1% per sex act transmission probability and a 3-month convalescent period (the two key unknown parameters of sexual transmission) create very few additional cases, but would extend the epidemic by 83 days [95% CI: 68-98 days] (p < 0.0001) on average. Strikingly, a 6-month convalescent period extended the average epidemic by 540 days (95% CI: 508-572 days), doubling the current length, despite an insignificant rise in the number of new cases generated. CONCLUSIONS/SIGNIFICANCE Our results show that reductions in the per sex act transmission probability via abstinence and condom use should reduce the number of sporadic sexual transmission events, but will not significantly reduce the epidemic size and may only minimally shorten the length of time the public health community must maintain response preparedness. While the number of infectious survivors is expected to greatly decline over the coming months, our results show that transmission events may still be expected for quite some time as each event results in a new potential cluster of non-sexual transmission. Precise measurement of the convalescent period is thus important for planning ongoing surveillance efforts.

Comparison of compliance and immune response of drug users on the standard and accelerated hepatitis B vaccine schedules - Houston, Texas

Despite the availability of hepatitis B vaccine for over two decades, drug users and other high-risk adult populations have experienced low vaccine coverage. Poor compliance has limited efforts to reduce transmission of hepatitis B infection in this population. Evidence suggests that immunological response in drug users is impaired compared to the general population, both in terms of lower seroprotection rates and antibodies levels.^ The current study investigated the effectiveness of the multi-dose hepatitis B vaccine and compared the effect of the standard and accelerated vaccine schedules in a not-in-treatment, drug-using adult population in the city of Houston, USA.^ A population of drug-users from two communities in Houston, susceptible to hepatitis B, was sampled by outreach workers and referral methodology. Subjects were randomized either to the standard hepatitis vaccine schedule (0, 1-, 6-month) or to an accelerated schedule (0, 1-, 2-month). Antibody levels were detected through laboratory analyses at various time-points. The participants were followed for two years and seroconversion rates were calculated to determine immune response.^ A four percent difference in the overall compliance rate was observed between the standard (73%) and accelerated schedules (77%). Logistic regression analyses showed that drug users living on the streets were twice as likely to not complete all three vaccine doses (p=0.028), and current speedball use was also associated with non-completion (p=0.002). Completion of all three vaccinations in the multivariate analysis was also correlated with older age. Drug users on the accelerated schedule were 26% more likely to achieve completion, although this factor was marginally significant (p=0.085).^ Cumulative adequate protective response was gained by 65% of the HBV susceptible subgroup by 12-months and was identical for both the standard and accelerated schedules. Excess protective response (>=100 mIU/mL) occurred with greater frequency at the later period for the standard schedule (36% at 12-months compared to 14% at six months), while the greater proportion of excess protective response for the accelerated schedule occurred earlier (34% at 6 months compared to 18% at 12-months). Seroconversion at the adequate protective response level of 10 mIU/mL was reached by the accelerated schedule group at a quicker rate (62% vs. 49%), and with a higher mean titer (104.8 vs. 64.3 mIU/mL), when measured at six months. Multivariate analyses indicated a 63% increased risk of non-response for older age and confirmed the existence of an accelerating decline in immune response to vaccination manifesting after 40 years (p=0.001). Injecting more than daily was also highly associated with the risk of non-response (p=0.016).^ The substantial increase in the seroprotection rate at six months may be worth the trade-off against the faster antibody titer decrease and is recommended for enhancing compliance and seroconversion. Utilization of the accelerated schedule with the primary objective of increasing compliance and seroconversion rates during the six months after the first dose may confer early protective immunity and reduce the HBV vulnerability of drug users who continue, or have recently initiated, increased high risk drug use and sexual behaviors.^

Flower and seed biomass, and germination rate of arctic tundra plants in response to long term experimental warming

We provide new information on changes in tundra plant sexual reproduction in response to long-term (12 years) experimental warming in the High Arctic. Open-top chambers (OTCs) were used to increase growing season temperatures by 1-2 °C across a range of vascular plant communities. The warming enhanced reproductive effort and success in most species; shrubs and graminoids appeared to be more responsive than forbs. We found that the measured effects of warming on sexual reproduction were more consistently positive and to a greater degree in polar oasis compared with polar semidesert vascular plant communities. Our findings support predictions that long-term warming in the High Arctic will likely enhance sexual reproduction in tundra plants, which could lead to an increase in plant cover. Greater abundance of vegetation has implications for primary consumers - via increased forage availability, and the global carbon budget - as a function of changes in permafrost and vegetation acting as a carbon sink. Enhanced sexual reproduction in Arctic vascular plants may lead to increased genetic variability of offspring, and consequently improved chances of survival in a changing environment. Our findings also indicate that with future warming, polar oases may play an important role as a seed source to the surrounding polar desert landscape.

Sex differences in the response to resistance exercise training in older people

Funding Information This work was supported by the Biotechnology and Biological Sciences Research Council (BB/J015911/1)

Response-reinforcement learning is dependent on N-methyl-d-aspartate receptor activation in the nucleus accumbens core

The nucleus accumbens, a site within the ventral striatum, is best known for its prominent role in mediating the reinforcing effects of drugs of abuse such as cocaine, alcohol, and nicotine. Indeed, it is generally believed that this structure subserves motivated behaviors, such as feeding, drinking, sexual behavior, and exploratory locomotion, which are elicited by natural rewards or incentive stimuli. A basic rule of positive reinforcement is that motor responses will increase in magnitude and vigor if followed by a rewarding event. It is likely, therefore, that the nucleus accumbens may serve as a substrate for reinforcement learning. However, there is surprisingly little information concerning the neural mechanisms by which appetitive responses are learned. In the present study, we report that treatment of the nucleus accumbens core with the selective competitive N-methyl-d-aspartate (NMDA) antagonist 2-amino-5-phosphonopentanoic acid (AP-5; 5 nmol/0.5 μl bilaterally) impairs response-reinforcement learning in the acquisition of a simple lever-press task to obtain food. Once the rats learned the task, AP-5 had no effect, demonstrating the requirement of NMDA receptor-dependent plasticity in the early stages of learning. Infusion of AP-5 into the accumbens shell produced a much smaller impairment of learning. Additional experiments showed that AP-5 core-treated rats had normal feeding and locomotor responses and were capable of acquiring stimulus-reward associations. We hypothesize that stimulation of NMDA receptors within the accumbens core is a key process through which motor responses become established in response to reinforcing stimuli. Further, this mechanism, may also play a critical role in the motivational and addictive properties of drugs of abuse.

Genomic evidence for a complete sexual cycle in Candida albicans

Candida albicans is a diploid fungus that has become a medically important opportunistic pathogen in immunocompromised individuals. We have sequenced the C. albicans genome to 10.4-fold coverage and performed a comparative genomic analysis between C. albicans and Saccharomyces cerevisiae with the objective of assessing whether Candida possesses a genetic repertoire that could support a complete sexual cycle. Analyzing over 500 genes important for sexual differentiation in S. cerevisiae, we find many homologues of genes that are implicated in the initiation of meiosis, chromosome recombination, and the formation of synaptonemal complexes. However, others are striking in their absence. C. albicans seems to have homologues of all of the elements of a functional pheromone response pathway involved in mating in S. cerevisiae but lacks many homologues of S. cerevisiae genes for meiosis. Other meiotic gene homologues in organisms ranging from filamentous fungi to Drosophila melanogaster and Caenorhabditis elegans were also found in the C. albicans genome, suggesting potential alternative mechanisms of genetic exchange.

Increased sexual activity reduces male immune function in Drosophila melanogaster

Despite the benefits of resistance, susceptibility to infectious disease is commonplace. Although specific susceptibility may be considered an inevitable consequence of the co-evolutionary arms race between parasite and host, a more general constraint may arise from the cost of an immune response. This “cost” hypothesis predicts a tradeoff between immune defense and other components of fitness. In particular, a tradeoff between immunity and sexually selected male behavior has been proposed. Here we provide experimental support for the direct phenotypic tradeoff between sexual activity and immunity by studying the antibacterial immune response in Drosophila melanogaster. Males exposed to more females showed a reduced ability to clear a bacterial infection, an effect that we experimentally link to changes in sexual activity. Our results suggest immunosuppression is an important cost of reproduction and that immune function and levels of disease susceptibility will be influenced by sexual selection.

Excitatory versus inhibitory GABA as a divergence point in steroid-mediated sexual differentiation of the brain

Whereas adult sex differences in brain morphology and behavior result from developmental exposure to steroid hormones, the mechanism by which steroids differentiate the brain is unknown. Studies to date have described subtle sex differences in levels of proteins and neurotransmitters during brain development, but these have lacked explanatory power for the profound sex differences induced by steroids. We report here a major divergence in the response to injection of the γ-aminobutyric acid type A (GABAA) agonist, muscimol, in newborn male and female rats. In females, muscimol treatment primarily decreased the phosphorylation of cAMP response element binding protein (CREB) within the hypothalamus and the CA1 region of the hippocampus. In contrast, muscimol increased the phosphorylation of CREB in males within these same brain regions. Within the arcuate nucleus, muscimol treatment increased the phosphorylation of CREB in both females and males. Thus, the response to GABA can be excitatory or inhibitory on signal-transduction pathways that alter CREB phosphorylation depending on the sex and the region in developing brain. This divergence in response to GABA allows for a previously unknown form of steroid-mediated neuronal plasticity and may be an initial step in establishing sexually dimorphic signal-transduction pathways in developing brain.

Comportamento e desempenho sexual de suínos reprodutores criados em ambientes enriquecidos

Este trabalho buscou avaliar o comportamento e o desempenho sexual de suínos machos de linhas puras e cruzadas, criados com e sem a utilização de enriquecimento ambiental, na fase de crescimento. A pesquisa foi dividida em duas etapas, que compreenderam a fase de crescimento dos animais e o treinamento para coleta de sêmen. Na fase de crescimento, 128 machos foram alojados em ambientes enriquecidos ou estéreis. Utilizou-se como enriquecimento ambiental correntes suspensas, galão de cinco litros suspenso e um galão de 50 litros solto no piso. Esses objetos foram oferecidos de forma alternada e cada um ficou disponível na baia por um período de 30 dias. Na primeira etapa foram registrados o comportamento dos animais, os escores de lesão e a massa corporal. Após a fase de crescimento, foram escolhidos aleatoriamente 32 animais aprovados na seleção genética para serem avaliados durante o treinamento para coleta de sêmen. O treinamento ocorreu durante seis dias consecutivos e cada animal foi treinado por três vezes em dias alternados. Durante o treinamento para a coleta de sêmen, o comportamento animal, as relações humano-animal, o volume do ejaculado e os níveis de testosterona e cortisol foram registrados. Como respostas na fase de crescimento, verificou-se que, mesmo utilizando uma combinação de objetos, os suínos se habituaram rapidamente a eles e a frequência de manipulação diminuiu após o primeiro período para todos os objetos. Observamos que o ambiente enriquecido foi eficaz na redução dos comportamentos agonísticos e mordedura de cauda e orelha para os animais puros e cruzados, e isso consequentemente reduziu a quantidade e severidade de lesões de pele. Na fase de treinamento para coleta de sêmen, os resultados demonstraram que o comportamento sexual dos animais foi influenciado pelas linhas genéticas, sendo assim, observou-se que os machos de linha cruzada tiveram maior facilidade durante o treinamento para coleta de sêmen e apresentaram maior média do escore de libido, diferindo das linhas puras (P<0,001). Verificou-se que não houve diferença na média do escore de libido entre os tratamentos com e sem enriquecimento ambiental (P=0,276), porém, os tratamentos com enriquecimento tiveram o menor número de animais treinados. Dessa forma, os resultados indicam que o ambiente enriquecido com uma combinação de enriquecimentos pontuais (objetos) é uma estratégia eficaz para aumentar o comportamento exploratório e reduzir os comportamentos agonísticos e anormais na fase de crescimento. Mas, por outro lado, os animais criados em ambientes enriquecidos tiveram um pior desempenho sexual durante o treinamento para coleta de sêmen.