Browsing by Author "Murias, Kara Rochele"

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    Pregnancy-Specific Anxiety and Maternal Social Support: Relationships with Offspring Attention and Executive Function Through Epigenetic Age
    (2023-08) Lowe, Catherine T.; Climie, Emma Alison; Ross, Kharah MacKenzie; Climie, Emma A.; Ross, Kharah MacKenzie; Letourneau, Nicole Lyn; Murias, Kara Rochele
    Prenatal exposure to maternal distress, such as pregnancy-specific anxiety, is associated with diminished child attention and executive functioning, commonly experienced with attention deficit/hyperactivity disorder (ADHD). Maternal social support is related to better child outcomes. In utero experiences can affect genetic expression by fine-tuning child phenotypes, potentially through child epigenetic age differences relative to chronological age through DNA methylation (DNAm), but whether this relates to child attention or executive function or mediates protective factors such as social support is unknown. Pregnant women (n = 96) reported pregnancy-specific anxiety and social support, and their 3-month-old infant buccal epithelial and buffy coat cell tissue samples were collected and assayed for DNAm, indicating epigenetic age differences identified through the Horvath Pan-Tissue clock. Children’s executive function and attention were assessed using the Behavior Assessment System for Children (2nd Ed) at 5 years of age. Multiple regression and structural equation mediation path analysis examined associations and indirect pathways between pregnancy-specific anxiety and social support on child attention and executive functioning through epigenetic age difference. Neither pregnancy-specific anxiety nor social support showed direct or indirect associations with children’s attention. However, pregnancy-specific anxiety and social support independently indirectly predicted better child executive functioning, mediated through increased, or biologically older, epigenetic age differences. Small to moderate amounts of pregnancy-specific anxiety is a normative and non-pathological experience, differentiated from maternal distress broadly. Both pregnancy-specific anxiety and social support are related to child DNAm, suggesting a possible impact on phenotype expression with implications for future research directions and potential targeted psychosocial interventions to preserve child executive functioning.
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    The effect of induced stress on long-term memory in lymnaea stagnalis
    (2006) Murias, Kara Rochele; Lukowiak, Ken
    Lymnaea stagnalis is a pond snail that has proven useful for studies of learning and memory of aerial respiration. Aerial respiration is an easily quantified behaviour that is controlled by a central pattern generator whose necessity and sufficiency has been directly demonstrated. If snails are exposed to an aversive chemical stimulus ( causes a defensive behaviour without causing permanent harm) before or after conditioning, a training schedule that normally only results in intermediate-term memory, causes long­term memory persisting at least 24 hours. A single application of an aversive chemical stressor is also capable of forming long-term memory if the application is contingent with pneumostome opening. Therefore training related to stress or a particularly aversive stimulus is enhanced and, therefore, results in long-term memory. This memory has many of the same characteristics as memory from more extensive training but is, in general, more resistant to manipulation after consolidation.