This is a cross-disciplinary pilot study to "reserve engineer" a portion of the cardiovascular control system. The central nervous system component of the baroreceptor reflex, a control mechanism that attempts to keep arterial pressure approximately constant, will be studied using intracellular recordings. Emphasis will be on the portion of the reflex that alters vagal control of heart rate in response to changes in arterial pressure. A computer model of the system will be used to develop principles for the control of chemical processes. The expectation is that understanding natural control mechanisms will aid the development of improved algorithms for controlling engineering systems.