Cardiovascular regulation in Squamates: validation of the decerebrated rattlesnake model for studies on regulatory processes of the cardiovascular system

• Grant number: 18/05035-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2018
• End date: March 31, 2021
• Field of knowledge: Biological Sciences - Zoology - Physiology of Recent Groups
• Principal Investigator: Cléo Alcantara Costa Leite
• Grantee: Cléo Alcantara Costa Leite
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated researchers: Renato Filogonio

Abstract

The Autonomic Nervous System (ANS) is responsible for the integration of several systemic functions in order to maintain of homeostasis at rest to support a diversity of biological challenges, in preparation for cyclic events, or for coordination of adjustments to face specific physiological states. The effort to evaluate autonomic functions and/or the functional role of specific adjustments often relates to a great instrumental challenge and deals with the impact of animal stress - by animal handling and procedures development -, or autonomic attenuation by anesthesia. Decerebrated animals have its cortex and thalamus removed and, after anesthetic recovery, the animal remains with a big part of its physiological operational functions, allowing monitoring and study without, however, any processing related to pain or conscious awareness. Such kind of preparation has been used to deepen investigations in several areas of zoology, physiology and health. Such preparations can provide access to a large number of information that could not otherwise be obtained, allowing significant advances in several areas with the use of a reduced number of animals. With this project, we suggest to validate and adjust a decerebrated rattlesnake model to be able to access several regulatory mechanisms. With that model, it will be possible to acquire and combine multiple cardiorespiratory, metabolic and temperature data and so, we will be able to address complex questions about the autonomic regulation of physiological processes. The present proposal is the initial movement for a long-term investigation plan on autonomic function and cardiorespiratory and vascular adjustments. In this initial project, we aimed to analyze the feasibility of the decerebration procedure on rattlesnakes and also to test a series of autonomic reflexes to determine the impact of this model. So, the snakes will be descerebrated to account for two experimental groups (anesthetized and non-anesthetized decerebrated snakes) that will have cardiovascular parameters: fH; HRV; blood pressure (systemic and pulmonary - S-P), stroke volume (S-P), resistance (S-P), baroreflex gain, central and superficial temperature, among other factors analyzed in relation to stimuli that would trigger autonomic reflexes for cardiovascular adjustments: head lift, tail lift, skin heating, blood pressure by drugs stimulation and chemoreceptors stimulation. We will work with the hypotheses that the use of anesthetized animals reduces the effectiveness of investigations that depend on the ANS integrity; and that the decerebrated rattlesnake model can provide (in terms of responsiveness and magnitude) the parameters analyzed. We judge that the model, since its viability was demonstrated, will be of extreme relevance for autonomic, cardiovascular and respiratory studies in reptiles and vertebrates. The possibility of access and analyze multiple data will also provide us the reduction of the number of used animals. (AU)

Scientific publications

(12)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ODA, GUSTAVO MAREGA; COSTA LEITE, CLEO ALACANTARA; ABE, AUGUSTO SHINYA; KLEIN, WILFRIED. Effects of different levels of hypoxia and hypercarbia on ventilation and gas exchange in Boa constrictor amaralis and Crotalus durissus (Squamata: Serpentes). Respiratory Physiology & Neurobiology, v. 294, DEC 2021. (18/05035-0)

FILOGONIO, RENATO; NETO, ANTONIO V. G. S.; ZAMPONI, MARIANA M.; ABE, AUGUSTO S.; LEITE, CLEO A. C.. Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus. JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL, v. 191, n. 5, AUG 2021. (16/20158-6, 19/22016-2, 18/05035-0)

FILOGONIO, RENATO; DUBANSKY, BENJAMIN D.; DUBANSKY, BROOKE H.; WANG, TOBIAS; ELSEY, RUTH M.; LEITE, CLEO A. C.; CROSSLEY, II, DANE A.. Arterial wall thickening normalizes arterial wall tension with growth in American alligators, Alligator mississippiensis. JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL, v. 191, n. 3, FEB 2021. (16/20158-6, 18/05035-0)

FILOGONIO, RENATO; ORSOLINI, KARINA F.; ODA, GUSTAVO M.; MALTE, HANS; LEITE, CLEO A. C.. Baroreflex gain and time of pressure decay at different body temperatures in the tegu lizard, Salvator merianae. PLoS One, v. 15, n. 11, NOV 23 2020. (16/20158-6, 18/05035-0)

CASTRO, SAMANTA APARECIDA; TAYLOR, EDWIN WILLIAM; TAVARES, DRIELE; FILOGONIO, RENATO; RODRIGUES, GERSON JHONATAN; LEITE, CLEO ALCANTARA COSTA.

Role of Nitric Oxide in the Cardiovascular System of South American Rattlesnakes (Crotalus durissus)

. PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY, v. 95, n. 2, p. 15-pg., 2022-03-01. (18/05035-0)

FILOGONIO, RENATO; ORSOLINI, KARINA F.; CASTRO, SAMANTA A.; ODA, GUSTAVO M.; ROCHA, GABRIELLA C.; TAVARES, DRIELE; ABE, AUGUSTO S.; LEITE, CLEO A. C.. Evaluation of the sequence method as a tool to assess spontaneous baroreflex in reptiles. JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY, v. 331, n. 7, p. 374-381, AUG 2019. (18/05035-0)

FILOGONIO, RENATO; DUBANSKY, BENJAMIN D.; DUBANSKY, BROOKE H.; LEITE, CLEO A. C.; CROSSLEY, II, DANE A.. renatal hypoxia affects scaling of blood pressure and arterial wall mechanics in the common snapping turtle, Chelydra serpentin. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, v. 260, OCT 2021. (18/05035-0, 16/20158-6)

FILOGONIO, RENATO; ORSOLINI, KARINA F.; CASTRO, SAMANTA A.; ODA, GUSTAVO M.; ROCHA, GABRIELLA C.; TAVARES, DRIELE; ABE, AUGUSTO S.; LEITE, CLEO A. C.. Evaluation of the sequence method as a tool to assess spontaneous baroreflex in reptiles. OURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOG, v. 331, n. 7, p. 8-pg., 2019-08-01. (18/05035-0)

FILOGONIO, RENATO; RODRIGUES, GERSON J.; LEITE, CLEO A. C.. Ontogenetic scaling of the baroreflex function in the green iguana (Iguana iguana). AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, v. 323, n. 6, p. 11-pg., 2022-12-01. (18/05035-0, 16/20158-6, 18/10588-9)

CASTRO, SAMANTA APARECIDA; TAYLOR, EDWIN WILLIAM; TAVARES, DRIELE; LEITE, CLEO ALCANTARA COSTA. Adrenergic control of functional characteristics of the cardiovascular system in the South American rattlesnake, Crotalus durissus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, v. 281, p. 12-pg., 2023-07-01. (18/05035-0)

ROCHA, GABRIELLA CAMPOS; CASTRO, SAMANTA APARECIDA; TAYLOR, EDWIN WILLIAM; TAVARES, DRIELE; LEITE, CLEO ALCANTARA COSTA. A Decerebrate Preparation of the Rattlesnake, Crotalus durissus, Provides an Experimental Model for Study of Autonomic Modulation of the Cardiovascular System in Reptiles. PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY, v. 94, n. 5, p. 269-285, SEP 1 2021. (18/05035-0)

TAVARES, DRIELE; MATOS, SOFIA LOPES BASILIO DA SILVA; DURAN, LIVIA MARIA; CASTRO, SAMANTA A.; TAYLOR, EDWIN WILLIAM; FILOGONIO, RENATO; FERNANDES, MARISA NARCISO; LEITE, CLEO A. C.. Baroreflex responses of decerebrate rattlesnakes (Crotalus durissus) are comparable to awake animals. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, v. 273, p. 8-pg., 2022-08-10. (16/20158-6, 18/05035-0)