RTI uses cookies to offer you the best experience online. By clicking “accept” on this website, you opt in and you agree to the use of cookies. If you would like to know more about how RTI uses cookies and how to manage them please view our Privacy Policy here. You can “opt out” or change your mind by visiting: http://optout.aboutads.info/. Click “accept” to agree.
Heart rate and respiration in reptiles: Contrasts between a sit-and-wait predator and an intensive forager
Porges, S., Riniolo, TC., McBride, T., & Campbell, B. (2003). Heart rate and respiration in reptiles: Contrasts between a sit-and-wait predator and an intensive forager. Brain and Cognition, 52(1), 88-96. https://doi.org/10.1016/S0278-2626(03)00012-5
The current study investigated respiration and heart rate in two species of reptiles with distinct behavioral strategies: (1) the Sudan plated lizard (Gerrhosaurus major), a sit-and-wait predator; and (2) the Savanna monitor (Varanus exanthematicus), an intensive forager. It was hypothesized that (a) the plated lizard would not express respiratory sinus arrhythmia, and (b) the monitor, a reptile with behavioral and physiological characteristics similar to mammals, might express respiratory sinus arrhythmia, a pattern previously observed only in mammals. The data demonstrated that although there were strong vagal influences on the heart, respiratory activity was not manifested in the heart rate pattern of the plated lizards. In contrast, the monitor exhibited a reliable ventilatory influence on the heart rate pattern, although the pattern differed from the respiratory sinus arrhythmia observed in mammals. Consistent with the Polyvagal Theory (Porges, 1995, 2001), the vagal control of the reptilian heart in both species appears to be mediated through the phylogenetically older unmyelinated system, a system that evolved to support metabolic conservation and not social behavior. (C) 2003 Elsevier Science (USA). All rights reserved