Mechanisms of circulatory homeostasis and response in Aplysia.

This review concerns the organization and function of arterial vasculature in Aplysia californica, especially the vasomotor reflexes that support circulatory homeostasis, and fixed patterns of response that may reroute blood flow during changes in behavioral state. The observations presented here raise three hypotheses for further study: 1) Arterial vasculature is functionally organized with precisely structured, independently regulated subdivisions; these are most evident for arterial systems serving digestive and reproductive processes; 2) arterial musculature is inherently responsive to local pressure changes, having both static and dynamic reflexes that promote efficient, evenly-distributed flow of blood; and 3) complex, long-lasting behaviors like egg laying have, as part of their makeup, equally prolonged and stereotypical changes in the pattern of circulation. Taken together, these observations support the view that maintenance and adjustment of blood flow in gastropod molluscs is an unexpectedly complex and highly integrated component of behavior.