UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

Browse

Filters

2020 - 20212

Settings

Subject: search.filters.subject.social isolation

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    INTERACTIONS BETWEEN SEROTONIN AND BEHAVIORAL SENSITIVITY TO ACUTE ALCOHOL EXPOSURE IN CRAYFISH
    (2021) Ho, Tawen; Herberholz, Jens; Neuroscience and Cognitive Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Social isolation has been found to correlate with an increase in alcohol consumption in humans. However, neurobehavioral and neurocellular mechanisms underlying interactions between alcohol and social isolation have been understudied. Prior work has shown that socially isolated crayfish exhibit lower behavioral and neural sensitivity to acute ethanol (EtOH) exposure than communally-housed conspecifics. Here we report an important role of the serotonergic system in mediating this socially-dependent effect. We found that depletion of serotonin (5-HT) from serotonergic neurons reduced behavioral sensitivity to EtOH, but the effect was more pronounced in communally housed animals. In addition, antagonizing 5-HT2β receptors also reduced EtOH sensitivity, and more strongly in group-housed animals, suggesting a possible down-regulation of 5-HT2β receptors in isolates. Pre-treatment with a selective serotonin reuptake inhibitor (fluoxetine) produced opposite modulatory effects, affirming the role of 5-HT in shaping the interactions between social experience and EtOH sensitivity. Thus, we show here, for the first time, that behavioral sensitivity to acute EtOH (i.e., intoxication) in crayfish is partially mediated by 5-HT, and our results suggest specific 5-HT receptor subtypes as possible targets for these interactions. This work might have relevance for studying the neurochemical mechanisms underlying the interplay between social history and alcohol sensitivity in other organisms. However, due to large variability in the experimental data and differences in sample sizes across conditions, the results should be considered preliminary, and future work will be aimed at increasing sample sizes and replication of results.
  • Thumbnail Image
    Item
    Factors Contributing to the Experience of State Loneliness
    (2020) Rinderknecht, Robert Gordon; Lucas, Jeffrey W; Doan, Long; Sociology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    In this dissertation, I examine the factors that contribute to the experience of loneliness in daily life (i.e., state loneliness). In the first study, I propose that being alone is most likely to lead to feelings of loneliness when a person is expected to be social, relative to moments when there is less of an expectation to be social. In the second study, I propose that how people engage with others has implications for how lonely they will feel in a situation, and that the importance of how they engage with others will partly depend on the kinds of people present in the situation. In the third study, I propose that engagement with romantic partners will be less beneficial for avoiding state loneliness when experiencing work-schedule conflict, due to the detriment such conflict may have on relationship quality. The lack of research on state loneliness is related to the difficulty of collecting data during or near the moment in which it is experienced. In this dissertation, I overcome this challenge by developing a platform that allowed participants to conveniently provide the time-diary data utilized in all three studies. In Study 1, I found, as expected, that participants felt loneliest when isolated during normatively social times. Unexpectedly, normatively social activities and locations did not associate with the strongest feelings of state loneliness. Results for Study 2 came out largely as expected—engaging in a shared task (active engagement) associated with lower rates of state loneliness relative to mere co-presence (passive engagement), and the benefit of active over passive engagement was strongest among weak ties and, unexpectedly, family members. Lastly, as expected, results from Study 3 show that work-schedule conflict associated with heightened loneliness when engaging with romantic partners. Unexpectedly, this appears to be less related to relationship quality between romantic partners and more related to the association between work-schedule conflict and participants reporting being generally lonely. Results from these studies show how factors ranging from broad cultural beliefs to small changes in engagement influence the experience of loneliness throughout a day, while unexpected findings highlight the need for further research.