Operant conditioning and the modulation of cardiovascular function.

Operant learning appears to be one of the primary mechanisms underlying what cardiovascular and pulmonary physiologists have called adaptation, habituation, and central command. In general, studies that have attempted to use operant conditioning alone to create experimental models of behaviorally induced disease have been unsuccessful because the cardiovascular responses adapted or habituated over time. Thus, these studies have provided implicit demonstrations of the roles played by CNS and conditioning processes in achieving and preserving homeostasis. During the past few years those interested in behavioral contributions to cardiovascular pathology have therefore begun to look at interactions between behavior and other variables that might predispose organisms towards pathology (e.g. genetic background; excessive sodium intake). Perhaps even more promising has been the growth in the number of technically competent, well-controlled studies designed to investigate: (a) broad scientific questions of how behaviorally important processes such as learning and reinforcement interact with physiologically important variables such as blood flow redistribution and cardio-pulmonary integration; and (b) the role of behavioral variables in CNS control of the circulation. Based upon our survey of the recent literature, we believe that the time is ripe for those interested in cardiovascular neurobiology increasingly to include behavioral variables in their studies, because the raison d'etre of the CNS is to optimize the organism's ability to interact with its environment. Only when these organismic-environmental interactions are studied both behaviorally and physiologically, in a broad biological context, will it be possible to develop rational models of neuro-circulatory regulation.