Combining novel research and community-engaged learning in an undergraduate physiology laboratory course.

To better prepare physiology students for 21st century careers, we incorporated classroom-based undergraduate research experiences and service learning/community-engaged learning (SLCE) into a college-level physiology laboratory course. The interventions were incorporated over 4 yr and assessed using validated surveys of student-reported learning gains related to attitudes toward science, the scientific process, and career paths. Students reported the greatest learning gains in those years when students did novel research oriented around a common theme of water quality. The gains were greater than those of a matched cohort that participated in an apprentice-style summer undergraduate research experience. With respect to the SLCE related to youth science literacy, students provided evidence of learning related to academics, personal growth, and civic mindedness. For example, many expressed discomfort about being in a new situation, often describing the differences between themselves and the youth with whom they interacted. However, students also grew in confidence about collaborating with people who were different from them and in their role as the "scientist." Limitations of the study include the quasi-experimental design and the incorporation of multiple interventions at the same time. Future studies should examine improvement in content acquisition and competency-based learning skills. Nonetheless, these results suggest that both novel research and SLCE increase student learning in the context of an undergraduate physiology laboratory course. Many of the learning gains observed with the SLCE are particularly important for physiology students, many of whom aspire to careers in health sciences, where they will be regularly working with nonscientists.

Testing hypotheses about individual variation in plasma corticosterone in free-living salamanders.

In vertebrates, many responses to stress as well as homeostatic maintenance of basal metabolism are regulated by plasma glucocorticoid hormones (GCs). Despite having crucial functions, levels of GCs are typically variable among individuals. We examined the contribution of several physiological factors to individual variation in plasma corticosterone (CORT) and the number of corticotropin-releasing hormone (CRH) neurons in the magnocellular preoptic area of the brain in free-living Allegheny Mountain dusky salamanders. We addressed three hypotheses: the current-condition hypothesis, the facilitation hypothesis and the trade-off hypothesis. Differential white blood cell count was identified as a strong contributor to individual variation in baseline CORT, stress-induced CORT and the number of CRH neurons. In contrast, we found no relationship between CORT (or CRH) and body condition, energy stores or reproductive investment, providing no support for the current-condition hypothesis or the trade-off hypothesis involving reproduction. Because of the difficulties of interpreting the functional consequences of variation in differential white blood cell counts, we were unable to distinguish between the facilitation hypothesis or the trade-off hypothesis related to immune function. However, the strong association between differential white blood cell count and hypothalamic-pituitary-adrenal/interrenal (HPA/I) activation suggests that a more thorough examination of immune profiles is critical to understanding variation in HPA/I activation.