PhD Proposal Examination – Samantha Lauby (McGowan lab)

PhD Proposal Exam

Thursday April 6^th, 10:10 am – Earth Sciences Centre, Rm. 3087

Samantha Lauby (McGowan lab)

“Thyroid Hormones and Tactile Stimulation in Early-Life:  An Investigation of Mechanisms Mediating Later-Life Stress Responses“

Abstract

The stress response must be flexible in order to respond to a varying environment. It is also evident that the quality of care received in early life can affect later life stress responses in a long-term manner. In rodent models in the laboratory, handling by an experimenter early in life appears to optimally prepare pups for moderately stressful testing conditions in adulthood. Tactile stimulation provided by the mother in early life also appears to program stress-related responses in later-life. The thyroid system has been proposed to constitute a mechanism signaling these early life events.  To investigate their interaction, I will use a 2×2 study design, with supplemental tactile stimulation and manipulating ambient temperature during separation, during an early-life handling procedure in rats. I will then identify changes in thyroid hormone activity in circulating blood and brain tissue. In addition, I will examine behavioural, physiological, and transcriptional components of stress-related responses in these offspring. Finally, I will characterize mechanisms that underlie identified gene expression changes. I hypothesize that the effects of supplemental tactile stimulation depend on a drop in body temperature with a subsequent release of thyroid hormone. This research will elucidate biological mechanisms by which animals adapt to their environments and outcomes related to a match or mismatch between early-life programming and the later-life environment.