Development of Cardiovascular Regulatory Mechanisms: Exploring the Early Embryonic Frontier II

University Of North Texas, Denton TX

Investigators

Abstract

PROJECT SUMMARY - 0614815 The long-term goal of this program is to understand how regulation of physiological processes is integrated together with developmental processes in vertebrate embryos. Emphasis is on early embryonic development, which is both inadequately studied and poorly understood. Three research objectives integrate innovative developmental physiology experiments on the cardiovascular system of bird model embryos (chicken, emu) together with multi-faceted research training comprising graduate and undergraduate students collaborating with middle and high school teachers and their pupils. Specifically the aims of this project are: 1) Determination of the Development of Early Embryonic Cardiovascular Regulation. It is hypothesized that intrinsic cardiac mechanisms (muscle length-tension relationships), in concert with vascular autoregulation (constriction and dilation of blood vessels controlled at the local level), must be responsible for any regulation of early embryonic blood pressure and flow. To test this hypothesis, in vivo measurements of blood pressures and flows will be made during blood volume loading, as well as measurements of the effects of vasoactive substances and oxygen levels, will be used to determine the developmental onset of regulation. . 2) Exploration of the Development of Blood Volume Regulation. As second hypothesis is that blood volume is initially poorly regulated until neurally and/or hormonally regulated cardiovascular and renal mechanisms develop sufficiently. Fluid balance in bird embryos will be challenged through blood compartment loading and loss. Blood pressure, heart rate, red blood cell numbers, water transport out of the vessels and blood volume will then be measured to determine the developmental onset of compensatory mechanisms. 3) Expansion of Teacher Physiology Education Program. The PI's newly established Science and Math Advanced Research Techniques (SMART) program exposes highly motivated high school teachers to contemporary research in the PI's lab. In close collaboration with UNT's science pedagogy faculty in Arts and Sciences and in Education, this program will be expanded beyond high school to include middle school teachers, and will use more advanced assessment tools for evaluating performance improvement in program alumni (e.g. improved standardized student test scores and student advance placement course enrollment). Intellectual Merit: Key scientific contributions will emerge from these studies in three areas. 1) Little information exists on how vertebrate embryos develop physiologically. These measurements will provide vital, mechanistically-based information on the ontogeny of the early embryonic cardiovascular system (CVS), improving understanding of how cardiovascular regulation is affected by, and integrated with, developmental processes during organogenesis and embryonic growth. 2) This information will enable better interpretation of CVS phenotypic plasticity and yield greater understanding of the phenomenon of "fetal programming". 3) Enhanced understanding of embryonic physiology in vertebrates is vital prior to creating corrective procedures for congenital defects in the human fetus and even embryos. Broader Societal Impact: In addition to training undergraduates, graduates and post-docs, the SMART Program integrates research and education by including middle as well as high school students. SMART engages science school teachers in original physiology research in UNT's physiology laboratories. It is hypothesized that these teachers then impart their experience to their students, enhancing a love and fascination for science. Texas no longer has a single majority population, enabling the PI's lab to mentor minority graduate and undergrad students (>50% of the PI's lab personnel consist of minorities encouraged by NSF). Finally, development will continue for the NSF-supported Developmental Physiology community website by creating resource sections for specific cohorts (e.g. undergrads). As a further outreach mechanism, specific web material will be created to illustrat to the lay public why developmental physiology is an important NSF target for funding. In summary, this continuing research program will enhance understanding of embryonic physiology, yield new insights into developmental evolutionary biology, provide contemporary training opportunities for undergrads through post-doctoral fellows, and create discovery opportunities for school students.