I graduated from Dalhousie University with a Ph.D. in neuroscience in August of 2017, and shortly thereafter joined the O’Connell lab as a postdoctoral associate. I am interested in studying 'top-down' mechanisms regulating the development and maintenance of diet induced obesity (DIO). Appetitive circuits in the central nervous system are changed by nutritional experience and DIO. Thus, treatment strategies that aim to control appetite and decrease body weight must target these circuits. The O’Connell lab focuses on AgRP neurons in the hypothalamus and the impact that DIO has on their excitability, plasticity, and regulation of gene expression. By pairing advanced electrophysiological techniques, coupled with 'omics’, computational analyses, biochemical, and behavioral techniques we are able to probe the hypothalamus and further characterize the neuronal populations responsible for regulating appetite. Ultimately, we aim to identify novel therapeutic targets underlying development and maintenance of diet-induced obesity.
Dalhousie University Ph.D.,
Neuroscience Advisor: Dr. Tara Perrot and Ian Weaver
Dalhousie University M.Sc.,
Neuroscience Advisor: Dr. Tara Perrot
University of Nebraska at Omaha B.A.,
Psychology, minor Biology
Variation in response styles in the hypothalamic-pituitary-adrenal (HPA) axis are known to be predictors of short- and long-term health outcomes. The nature of HPA responses to stressors changes with developmental stage, and some components of the stress response exhibit long-term individual consistency (i.e., are trait-like) while others are transient or variable (i.e., state-like). Here we evaluated the response of marmoset monkeys (Callithrix geoffroyi) to a standardized social stressor (social separation and exposure to a novel environment) at three different stages of development: juvenile, subadult, and young adult. We monitored levels of urinary cortisol (CORT), and derived multiple measures of HPA activity: Baseline CORT, CORT reactivity, CORT Area Under the Curve (AUC), and CORT regulation. Juvenile marmosets exhibited the most dramatic stress response, had higher AUCs, and tended to show poorer regulation. While baseline CORT and CORT regulation were not consistent within an individual across age, CORT reactivity and measures of AUC were highly correlated across time; i.e., individuals with high stress reactivity and AUC as juveniles also had high measures as subadults and adults, and vice-versa. Marmoset co-twins did not exhibit similar patterns of stress reactivity. These data suggest that regardless of the source of variation in stress response styles in marmosets, individually-distinctive patterns are established by six months of age, and persist for at least a year throughout different phases of marmoset life history.