Browsing by Subject "Sexual behavior"

Now showing 1 - 3 of 3
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    Investigation of Glutamatergic Circuitry Underlying Copulatory Reward in Female Syrian Hamsters
    (2019-01) Moore, Kelsey
    Sex behavior in female mammals is known to involve rewarding consequences that increase the motivation to copulate. I have utilized female hamsters as a model to examine the underlying circuitry and mechanisms of this natural reward. Despite a wealth of information detailing dopaminergic neurotransmission in this region during sexual behavior, the role of glutamate, although the major excitatory neurotransmitter in the brain, has been disproportionately understudied. The goal of this dissertation work was to help close this gap in knowledge to further develop an understanding of the complex underpinnings of female sexual reward and motivation. This understanding is vital in the effort towards evidence-based therapeutic targets in the treatment of disorders of sexual desire in women. In order to determine the role of glutamate in signaling the rewarding properties of sex, I utilized a multi-faceted approach. First, through establishing the use of enzymatic biosensing in the lab, I evaluated glutamate release patterning in key reward regions during sexual behavior in the female hamster. I discovered time-locked glutamate transients specifically in the core of the nucleus accumbens (NAc) in response to penile intromission from the male. Next, I sought to uncover the potential source of this glutamate innervation of the NAc. Immunohistochemical and retrograde tracing analyses determined the involvement of excitatory glutamatergic efferents from the medial prefrontal cortex (mPFC) to the NAc. Then, to determine if mPFC activity was driving the activation of the NAc during female sexual behavior, I employed designer receptors exclusively activated by designer drugs (DREADDs) to selectively inhibit these excitatory mPFC efferents. I demonstrated that this selective inhibition decreases sex-induced activation of the NAc, confirming the importance of the mPFC in driving increased glutamatergic activity in the NAc in response to sexual behavior in the female. The novel findings reported in this body of work demonstrate the involvement of glutamatergic neurotransmission in sexual reward through a prefrontal-accumbal circuit. These are not only exciting additions to the development of a comprehensive model of female sexual reward, but also provide potential targets for therapeutic intervention. Currently there are no effective treatment options for disorders of sexual desire in women and these results provide attractive avenues for pursuing target-specific and clinically-relevant therapies.
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    Relationships between Adolescent Stress, Depressive Symptoms, Social Support, Coping and Sexual Risk Behavior in Young Adulthood
    (2017-01) Ghobadzadeh, Maryam
    Objective To describe longitudinal associations among adolescent stressful life events, depressive symptoms, coping skills, social support, and young adult sexual risk behaviors and sexually transmitted infection (STI) in the United States. Design A total of 18,924 participants aged from 12 to 18 at baseline were included in the analysis. The study's design was a secondary analysis of three waves of longitudinal data utilized structural equation modeling (SEM) to test direct and indirect effects of adolescent stressful life events, depressive symptoms, problem-focused coping skills, unhealthy coping strategies, and social support on young adult sexual risk behavior. To examine the hypotheses of this study, three main structural models were evaluated. Model 1 explores the effects of depressive symptoms and stressful life events as the potential mediator of the association between mental health problems and sexual risk behavior, while Model 2 tests mediating effect of unhealthy coping strategies. Lastly, Model 3 examines the indirect effects of problem-focused coping skills and social support on sexual risk behavior. Results As anticipated, direct effects were found for adolescent stressful life events and unhealthy coping strategies on young adult sexual risk behavior. Adolescent stressful life events and unhealthy coping also significantly mediated the relationship between depressive symptoms and young adult sexual risk behavior. Higher social support from family and problem-focused coping strategies were associated with lower depressive symptoms and stressful life events in adolescence. Adolescent social support from family and problem-focused coping skills were shown to influence young adult sexual risk behavior indirectly through reducing stressful life events. Conclusions Given the associations between stressful life events, depressive symptoms, and sexual risk behavior, these findings highlight a need for screening for depression and stressful life events in adolescents. Findings may also be useful to inform interventions for high-risk adolescents facing psychological stressors and suggest that coping skills training and enhancing social support should be specific targets.
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    Treat your partners right: Implication of sexual contact networks in partner management for sexually transmitted infections
    (2020-06) Kao, Szu-Yu
    Sexually transmitted infections (STIs) have continued to increase among the heterosexual population and men who have sex with men (MSM) in the last five years. To better inform STI control strategies, the factors that influence the disease dynamics of STIs can be important to incorporate in developing infectious disease modeling for cost-effectiveness analysis. The spread of STIs depends on the macrostructure (e.g., random, clustered, scale-free networks) and microstructure (e.g., relationship dynamics) of the contact networks, and the sexual behaviors (e.g., condom use) commonly adopted in the population. In this thesis, we investigated different aspects that could influence STI transmission and the cost and effectiveness of STI control strategies in the population of interest. First, we evaluated how the structure of sexual contact network influences the cost and effectiveness of partner management strategies controlling for bacterial STIs in MSM. We found that the network structure, the compliance to intervention, and the resource constraint matter in determining the optimal partner management strategy. Second, we evaluated how relationship dynamics affects the cost-effectiveness of partner management strategies and quantified the value of key measures (concurrency and the average relationship duration) that inform relationship dynamics. We found that modeling sexual contact networks without measures informing relationship dynamics might lead to recommendation of a less cost-effective partner management strategy to control bacterial STIs, resulting societal loss. The value of collecting concurrency information is higher than the value of relationship duration. Third, we explored how HIV status disclosure, partner selection and condom use behavior changed with HIV prevalence in MSM using evolutionary game theory. We found that these behaviors varied with HIV prevalence. In particular, HIV-positive individuals were more likely to disclose their status and less likely to use condom at a high HIV prevalence than at a low HIV prevalence. These behavior changes should be considered in cost-effectiveness analysis to better inform interventions of HIV/STIs.